[Client]

5.1.1 For the criteria as regards air quality impact assessment, reference shall be made 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).

5.1.2 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) as follows:

(a) 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

(b) Ensure that the AQO for 7 common air pollutants are met as soon as possible.

5.1.3 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 5-1 Hong Kong Air Quality Objectives (HKAQO)

	Limits on Concentration, ug/m³ ^[1] (ppm in brackets)
Pollutant	1-hr ^[2]	8-hr ^[3]	24-hr ^[3]	Monthly ^[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.

5.1.4 The key air emission source from HKLR and HKBCF is obviously the road traffic (ie vehicular emission). In this regard, air pollutants of concern would include nitrogen dioxide (NO2) and respirable suspended particulates (RSP), and they have been assessed in this study. The emissions as regards other pollutants such as CO etc from road traffic are insignificant.

5.2 Ambient Air Quality Condition and Previous Monitoring Levels

5.2.1 Existing air sensitive receivers in the vicinity of the project include various developments (residential, commercial etc) and village houses along the northern coast of Lantau (see Section 5.3). Key existing air pollution sources that may bear upon the air quality in Tung Chung/North Lantau include the roads (notably North Lantau Highway), the Chek Lap Kok Airport i.e. Hong Kong International Airport, Black Point Power Station, Castle Peak Power Station and the Lamma Power Station. Other regional emission sources beyond HK would also have certain influence on the background air quality level. Details of air pollution emission sources are discussed in Sections 5.5 & 5.6.

5.2.2 Historical air quality monitoring data from the nearest monitoring station, namely the Tung Chung station operated by EPD, have been examined. The latest 5 published years of air quality monitoring data, i.e. 2004 to 2008 at Tung Chung Monitoring Station are tabulated in the table below.

Table 5-2 Air Quality Monitoring Data (Tung Chung Station, 2004-2008)

Pollutant	Year	Highest 1-Hour Average (mg/m³)	Highest Daily Average (mg/m³)	Annual Average (mg/m³)
SO₂	2004	432	115	27
	2005	301	121	21
	2006	393	209	25
	2007	259	95	23
	2008	266	91	18
	5-year mean ^[3]	330 (41%)	126 (36%)	23(29%)
	AQO – SO₂	800	350	80
NO₂	2004	289	166	52
	2005	268	147	46
	2006	253	157	47
	2007	248	127	46
	2008	256	134	49
	5-year mean ^[3]	263 (88%)	146 (97%)	48(60%)
	AQO – NO₂	300	150	80
TSP	2004	N/M	176	72
	2005	N/M	261	65
	2006	N/M	160	75
	2007	N/M	240	70
	2008	N/M	198	69
	5-year mean ^[3]	N/M	207(80%)	71 (89%)
	AQO - TSP	N/M	260	80
CO	2004	3940	3385	799
	2005	5730	4541	923
	2006	3670	260	782
	2007	3920	3514	820
	2008	2820	2566	860
	5-year mean ^[3]	4016(13%)	2853(29%)	837
	AQO - CO	30,000	10,000	N/A
RSP	2004	389	209	62
	2005	366	217	57
	2006	314	254	56
	2007	NM	199	54
	2008	243	146	52
	5-year mean ^[3]	328	205(113%)	56(102%)
	AQO - RSP	N/A	180	55
O₃	2004	403	138	48
	2005	357	140	38
	2006	302	107	37
	2007	308	117	40
	2008	310	146	41
	5-year mean ^[3]	336 (140%)	130	41
	AQO – O₃	240	N/A	N/A

Note:

[1] N/M - Not Measured

[2] Monitoring results exceeded AQO are shown as underlined characters.

[3] % of AQO is provided in the bracket. The 5-year mean is the average of the yearly maximum.

n.a Not applicable since there is no HKAQO for this parameter.

5.2.3 It can be seen from the above table that the highest 1-hour NO₂ concentration has gradually decreased from 289ug/m³ in 2004 to 256ug/m³ in 2008, against a criterion of 300ug/m³. A similar trend is also observed for the daily NO₂ concentration, which has decreased from 166ug/m³ in 2004 to 134ug/m³ in 2008. The maximum daily NO₂ concentration at 2004 and 2006, however, exceeded the criterion of 150ug/m³. The annual NO₂ remains relatively steady in the range of 46 - 52ug/m³, without any exceedance of the criterion of 80ug/m³.

5.2.4 For RSP, the maximum daily concentration exceeded the AQO (in the range of 199-254ug/m³ in 2004 – 2007, against the AQO of 180ug/m³), but the concentration became AQO-compliant in 2008, being the lowest among the last 5 years. The annual RSP concentration shows a decreasing trend, with the 2008 annual RSP concentration being 52ug/m³ without exceeding the criterion of 55ug/m³.

5.2.5 The maximum hourly concentration of O₃ from 2004 – 2008 has been relatively high, in the range of 302 – 403ug/m³, against the AQO of 240ug/m³. However, the proposed project will not generate any O_3. Hence, O₃ is not a pollutant to be assessed in this EIA.

5.2.6 For SO₂ and CO, the pollutant level are relatively low, in the order of less than 41% and less than 13% of the corresponding hourly AQOs respectively. Hence, SO₂ ad CO will not be assessed in this EIA.

5.2.7 For suspended particulates, road traffic emissions will mainly contribute to RSP. Hence, RSP will be included in the operation phase air quality assessment. However, the construction phase of the project will involve the emission of fugitive dusts, and hence TSP will be assessed for construction phase air quality impact.

5.3 Air Sensitive Receivers & Pollution Sources

5.3.1 Air Sensitive Receivers

5.3.1.1 With reference to EIA Study Brief No. ESB-110/2003 for HKLR and ESB-183/2008 for HKBCF, the study area for air quality impact assessment should generally be defined by a distance of 500m from the boundary of the project site. Further, it should be extended to include major emission sources that may have a bearing on the environmental acceptability of the project. The study will also review the air quality impacts on the areas and other sensitive receivers beyond 500m from the site boundary, which may be potentially affected by the Project.

5.3.1.2 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 would also be considered as a sensitive receiver.

5.3.1.3 Representative ASRs within a distance of 500m from the project boundary (including the proposed alignment, reclamation and the associated facilities) have been identified. Since there are some ASRs located outside the 500m range, representative ASRs beyond 500m from the project boundary have therefore been included in the assessment.

5.3.1.4 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 include scattered village houses generally in 1 to 3-storeys high, as well as residential / commercial developments in Tung Chung/North Lantau.

5.3.1.5 Planned/committed ASRs are identified by making reference to relevant Outline Zoning Plans (OZP), Outline Development Plans, Layout Plans and other published plans in relation to the development on North Lantau, including:

· Tung Chung Town Centre Area OZP (No. S/I-TCTC/13);

· Tung Chung Town Centre Area Layout Plan - Lantau Island (No. L/I-TCTC/1C);

· North Lantau New Town Phase IIB Area (Part) Layout Plan (No. L/I-TCIIB/1C).

5.3.1.6 The relevant stakeholders were also approached to obtain latest information on planning application, layout and building height. The major planned uses in the vicinity of the area include:

· Tung Chung East and West Further Developments (whilst there are no confirmed development layout, this EIA has included indicative locations to assess the future air quality impacts);

· Possible tourism initiatives in Lantau (including the possible Theme Park and the Sunny Bay Tourism node as indicated in the Concept Plan for Lantau);

· Lantau Logistics Park; and

· The possible transport hub at MTRCL Siu Ho Wan Depot.

5.3.1.7 The locations of the representative ASRs for air quality assessment during the implementation of the project are illustrated in Figure 5.1, and are summarised in the table below. ASRs at eastern coast of Tung Chung East Future Development, LLP, MTR Siu Ho Wan Depot etc are considered in the EIA for TMCLKL.

Table 5-3 Representative ASRs for Air Quality Impact Assessment

ASR ID	Description	Area	No. of Storey (approx)	Urban /Rural ^[1]	Land use ^[2]
A93	Sha Lo Wan House No. 1	Sha Lo Wan^[A]	1-3	Rural	Res
A94	Sha Lo Wan House No. 5		1-3	Rural	Res
A95	Sha Lo Wan House No. 9		1-3	Rural	Res
A96	Tin Hau Temple at Sha Lo Wan		1-3	Rural	Res
A97	San Shek Wan	San Shek Wan^[A]	1-3	Rural	Res
A98	Sham Wat House No. 39	Sham Wat^[A]	1-3	Rural	Res
A99	Sham Wat House No. 30		1-3	Rural	Res
A90	Tin Sum	Tim Sum^[A]	1-3	Rural	Res
A91	Kau Liu		1-3	Rural	Res
A92	San Tau		1-3	Rural	Res
A59	Ma Wan Chung	Ma Wan Chung^[A]	1-3	Rural	Res
A41	One Citygate	Existing Tung Chung Town (South of NLH)^[A]	5	Urban	Res
A42	One Citygate Bridge		10	Urban	Res
A43	Fu Tung Shopping Centre		4	Urban	Com
A44	Tung Chung Health Centre		3	Urban	GIC
A45	Ching Chung Hau Po Woon Primary School		7	Urban	GIC
A46	Po On Commercial Association Wan Ho Kan Primary School		7	Urban	GIC
A47	Po Leung Kuk Mrs. Ma Kam Min Cheung Fook Sien College		7	Urban	GIC
A48	Wong Cho Bau Secondary School		7	Urban	GIC
A49	Tung Chung Wan Telephone Exchange		5	Urban	GIC
A50	Yu Tung Court - Hei Tung House		33	Urban	Res
A51	Yu Tung Court - Hor Tung House		36	Urban	Res
A52	Fu Tung Estate - Tung Ma House		30	Urban	Res
A53	Fu Tung Estate - Tung Shing House		30	Urban	Res
A54	Tung Chung Crescent Block 1		28	Urban	Res
A55	Tung Chung Crescent Block 3		30	Urban	Res
A56	Tung Chung Crescent Block 5		33	Urban	Res
A57	Tung Chung Crescent Block 7		39	Urban	Res
A58	Tung Chung Crescent Block 9		43	Urban	Res
A60	Yat Tung Estate - Shun Yat House		35	Urban	Res
A51	Yu Tung Court - Hor Tung House		36	Urban	Res
A61	Yat Tung Estate - Mei Yat House		35	Urban	Res
A62	Yat Tung Estate - Hong Yat House		35	Urban	Res
A63	Yat Tung Estate - Ping Yat House		35	Urban	Res
A64	Yat Tung Estate - Fuk Yat House		35	Urban	Res
A65	Yat Tung Estate - Ying Yat House		35	Urban	Res
A66	Yat Tung Estate - Sui Yat House		35	Urban	Res
P3	Planned Park near One Citygate		1	Urban	OS
A1	Caribbean Coast Block 1 – Facing NLH	Existing Tung Chung Town (North of NLH)^[A]	47	Urban	Res
A2	Caribbean Coast Block 1 – Facing BCF		47	Urban	Res
A3	Caribbean Coast Block 5 – Facing NLH		49	Urban	Res
A4	Caribbean Coast Block 5 – Facing BCF		49	Urban	Res
A5	Caribbean Coast Block 6 – Facing NLH		51	Urban	Res
A6	Caribbean Coast Block 6 – Facing BCF		51	Urban	Res
A7	Caribbean Coast Block 9 – Facing NLH		52	Urban	Res
A8	Caribbean Coast Block 9 – Facing BCF		52	Urban	Res
A9	Caribbean Coast Block 11 – Facing NLH		52	Urban	Res
A10	Caribbean Coast Block 11 – Facing BCF		52	Urban	Res
A11	Caribbean Coast Block 16 – Facing NLH		51	Urban	Res
A12	Caribbean Coast Block 16 – Facing BCF		51	Urban	Res
A13	Caribbean Coast (Phase 5)		3	Urban	Res
A14	Caribbean Coast (Phase 5)		3	Urban	Res
A15	Ho Yu College		7	Urban	GIC
A16	Ho Yu Primary School		7	Urban	GIC
A17	Coastal Skyline Block 1 – Facing NLH		50	Urban	Res
A18	Coastal Skyline Block 1 – Facing HKLR		50	Urban	Res
A19	Coastal Skyline Block 5 – Facing NLH		50	Urban	Res
A20	Coastal Skyline Block 5 – Facing HKLR		50	Urban	Res
A21	La Rossa B – Facing NLH		56	Urban	Res
A22	La Rossa B – Facing HKLR		56	Urban	Res
A23	LeBleu No.1		1-3	Urban	Res
A24	LeBleu No.31		1-3	Urban	Res
A25	LeBleu No.99		1-3	Urban	Res
A26	LeBleu No.2		1-3	Urban	Res
A27	LeBleu No.22		1-3	Urban	Res
A28	LeBleu No.88		1-3	Urban	Res
A29	LeBleu Deux		1-3	Urban	Res
A30	LeBleu Deux		1-3	Urban	Res
A31	LeBleu Deux		1-3	Urban	Res
A32	LeBleu Deux		1-3	Urban	Res
A33	Seaview Crescent Block 5 – Facing NLH		50	Urban	Res
A34	Seaview Crescent Block 5 – Facing HKLR		50	Urban	Res
A35	Seaview Crescent Block 3 – Facing NLH		49	Urban	Res
A36	Seaview Crescent Block 3 – Facing HKLR		49	Urban	Res
A37	Seaview Crescent Block 1 – Facing NLH		49	Urban	Res
A38	Seaview Crescent Block 1 – Facing HKLR		49	Urban	Res
A39	Ling Liang Church E Wun Secondary School		7	Urban	GIC
A40	Ling Liang Church Sau Tak Primary School		7	Urban	GIC
A101	Novotel Citygate Hong Kong		30	Urban	Com
P4	Planned Community Hall and Library	^[B]	5	Urban	GIC
P5	Planned District Open Space	^[B]	1	Urban	OS
P6	Planned District Open Space	^[B]	1	Urban	OS
A100	Man Tung Road Park		1	Urban	OS
A67	Aviation Security Company Limited	Airport Island^[A]	10	Rural	Com
A68	Tradeport Logistics Centre		10	Rural	Com
A69	Tradeport Logistics Centre		10	Rural	Com
A70	Cathay Pacific City		10	Rural	Com
A71	Cathay Pacific City		10	Rural	Com
A72	Chek Lap Kok Fire Station		3	Rural	Com
A73	LSG Sky Chefs		10	Rural	Com
A74	LSG Sky Chefs		10	Rural	Com
A75	Cathay Pacific Catering Services		10	Rural	Com
A76	Cathay Pacific Catering Services		10	Rural	Com
A77	Airport Police Station		3	Rural	Com
A78	Gate Gourmet Catering Building		10	Rural	Com
A79	CNAC Tower		10	Rural	Com
A80	Dragonair Tower		10	Rural	Com
A81	Regal Airport Hotel		30	Rural	Com
A82	SkyCity Nine Eagles Golf Course		1	Rural	OS
A83	SkyCity Nine Eagles Golf Course		1	Rural	OS
A84	SkyCity Nine Eagles Golf Course		1	Rural	OS
A85	Hong Kong SkyCity Marriott Hotel		30	Rural	Com
A86	Hong Kong SkyCity Marriott Hotel		30	Rural	Com
A87	AsiaWorld-Expo		5	Rural	Com
A88	AsiaWorld-Expo		5	Rural	Com
A89	Government Flying Services Headquarters		10	Rural	GIC
A102	Terminal 2 Sky Plaza		5	Rural	GIC
A103	SkyCity Nine Eagles Golf Course		1	Rural	OS
A104	SkyCity Nine Eagles Golf Course		1	Rural	OS
A105	Hong Kong Business Aviation Centre		10	Rural	Com
A106	DHL Central Asia Hub		10	Rural	Com
P1	Tung Chung East Development	Planned ASRs^[B]	-	Urban	Res
P2	Tung Chung East Development		-	Urban	Res
P7	Tung Chung West Development		-	Urban	Res
P8	Tung Chung West Development		-	Urban	Res
P9	Tung Chung West Development		-	Urban	Res
P10	Tung Chung West Development		-	Urban	Res
P11	Tung Chung West Development		-	Urban	Res
P12	Future CAD Headquarters ((Road side)		10	Urban	GIC
P13	Future CAD Headquarters (5m setback)		10	Urban	GIC

Notes:

[A] For both construction and operation phase assessment.

[B] For operation phase assessment only.

[1] Classified into urban and rural categories

[2] Res – residential; Com – Commercial; OS – Open Space; GIC – Government/Institution

[3] The planning for the future Tung Chung East and West Further Development is still pending

[4] The ASRs in the eastern coast of Tung Chung East Future Development, Lantau Logistic Park and the MTRCL Siu Ho Wan Depot are assessed in the EIA Report for TMCLKL.

5.3.2 Air Pollution Sources

5.3.2.1 Both construction and operation of the project would inevitably generate air pollutants with potential impacts on neighbouring sensitive receivers. These air pollutant emission sources include:

Phase

Air Pollution Sources

Construction

· Fugitive dust from various construction activities, including excavation, stockpiling, barging, infrastructure works etc

· Fugitive dust from concrete batching plant (near Siu Ho Wan Sewage Treatment Works) and To Kau Wan (near Toll Plaza of NLH)

· Cut-and-cover section of the APM tunnel on the airport island

Operation

· Vehicular emissions from road traffic, including vehicles on roads, or at the HKBCF facilities (such as kiosks, loading/unloading bays).

5.3.2.2 It should be noted that marine works such as dredging, underwater filling during reclamation, and installation of viaduct decks would not significantly generate fugitive dust.

5.4 Potential Concurrent Projects

5.4.1 As discussed in Section 1, the tentative commissioning year of the project is 2015 for HKLR and 2015/2016 (Phase 1/Phase 2) for HKBCF. All concurrent projects, which may have cumulative environmental impacts during its operation period, have been identified and discussed in Section 1. The following table summarises the concurrent projects that would have cumulative air quality impacts during the construction and operation phases of the project.

Table 5-4 Key Concurrent Projects for Air Quality Assessment

Phase	Key Concurrent Projects	Remark
Construction	Lantau Logistics Park	Possible concurrent construction with HKLR and HKBCF
	Tuen Mun-Chek Lap Kok Link	Possible concurrent construction with HKLR and HKBCF
Operation	Lantau Logistics Park	Traffic induced has been included
	Possible LLP Extension or other compatible uses	Traffic induced has been included
	FutureTung Chung East & West Developments	Traffic induced has been included
	Road P1 in North Lantau (for the section from Sham Shui Kok to Sunny bay)	Traffic induced has been included
	Container Terminal 10	Emission from additional marine vessels
	Sunny Bay Tourism Node	Traffic induced has been included
	Theme Park Extension at Penny’s Bay	Traffic induced has been included
	Commercial developments on Airport Island	Traffic induced has been included
	MTRCL Siu Ho Wan Depot	Traffic induced has been included
	Castle Peak Power Station	Chimney emission has been included
	Black Point Power Station	Chimney emission has been included
	Lamma Power Station	Chimney emission has been included
	Hong Kong International Airport	Emissions from aircraft and other facilities has been included
	Sludge Treatment Facilities	Emission from incineration and any other related activities
	Tuen Mun-Chek Lap Kok Link	Vehicular emission has been included
	HZMB Main Bridge	Vehicular emission has been included
	Eco Park	Chimney emission has been included
	Green Island Garment	Chimney emission has been included
	STF	Chimney emission has been included

5.4.2 It should be noted that the traffic forecast for HKLR and HKBCF has in fact already taken account of traffic generated by the planned developments as tabulated above. Hence, the vehicular emission model has also covered all the traffic emissions from these planned developments as well.

5.5 Construction Dust Assessment

5.5.1 Potential Sources of Dust

5.5.1.1 A review has been conducted on the construction methodology (see Section 4 for details) for various works areas. Construction dust will be potentially generated from the mainly land-based construction works including the following activities:

· Filling;

· Soil excavation activities;

· Backfilling;

· Surcharge and temporary storage of spoil on site;

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

· Construction of infrastructure and utilities;

· Loading and unloading of excavated materials / fill materials at barging facility; and

· Concrete batching plant.

5.5.1.2 Other marine based construction activities such as seawall construction, dredging, marine bored piling, viaduct deck construction etc would have insignificant fugitive dust generation and hence would not be included in this quantitative assessment. Figure 5.2a shows the location of these dust emission sources.

5.5.1.3 According to the latest design information, the Passenger Clearance Building (PCB) on the HKBCF will be commissioned in 2015. Hence, during the period Late 2015 – Late 2016, the passengers and workers at the PCB will be in relatively close proximity to the remaining construction activities for the works in the northern portion of HKBCF as shown on Figure 1.2. The construction dust model would include all the concurrent construction activities (see S.5.5.3).

5.5.2 Emission Inventory

5.5.2.1 Fugitive dust impact assessments will be 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 open sites, including stockpile and barging area;

· Loading/unloading from trucks at barging point and stockpiles; and

· Concrete batching plant.

5.5.2.2 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. Calculation of dust emission factors is given in Appendix 5A. References of the calculations of dust emission factors for different dust generating activities are listed below. For easy reference, the locations of ASRs assessment points and worksites, and the dust emission rates input into the model are presented in Appendix 5B.

Table 5-5 References of Dust Emission Factors for Different Activities

Activities	Reference^[1]	Operating Sites	Equations and Assumptions
Heavy construction activities including land clearance, ground excavation, cut and fill operations, construction of the facilities, haul road, etc	S.13.2.3.3	All construction and excavation sites	E = 1.2 tons/acre/month of activity or = 2.69Mg/hectare/month of activity
Wind Erosion	S.11.9, Table 11.9.4	All construction sites, any stockpile areas, barging area (all open sites)	E = 0.85 Mg/hectare/yr (24 hour emission)
Loading/Unloading at barging points and any stockpile	S13.2.4	Barging point and/or any stockpiles	k is particle size multiplier U is average wind speed M is material moisture content

[1] (USEPA) Compilation of Air Pollution Emission Factors (AP-42), 5th Edition

5.5.2.3 Dust emission from construction vehicle movement will generally be limited within the confined worksites area and the equation 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.

5.5.2.4 If stockpiling is adopted, it is recommended that vehicles will move to the stockpiling areas where C&D materials will be unloaded immediately. The vehicles will then be washed again before leaving the stockpiles in order to minimise generation of dusty materials. Therefore, the major dust generating activities at stockpiling areas will be originated mainly from wind erosion and loading/unloading of materials; and these will be assumed in the fugitive dust modelling.

5.5.2.5 For the calculation of 1-hr and 24-hr TSP concentration, an active operating area of 30% has been assumed at any one time. Dust suppression measures and estimated mitigation efficiencies will be incorporated into the dust emission calculations. With reference to Section 11.2.4.4 of AP-42 4th Edition, dust emissions from construction areas could be reduced by 50% by twice daily watering with complete coverage of active construction areas. Dust generated from vehicle traffic on unpaved site roads (if any) would be reduced by lowering the vehicle travelling speed. The percentage dust reduction will be estimated in accordance with Section 13.2.2.2 of AP-42 5th Edition. For the calculation of annual TSP construction, the active works area over the entire year would be less than for a typical hour and typical day. On this basis, it is considered that a 10% active operating area would be a more representative assumption. The active operating area for 1-hr, 24-hr and annual concentration has been agreed by the Engineer.

5.5.2.6 There would also be concrete batching plant at temporary works area at Tai Ho (near Siu Ho Wan Sewage Treatment Works) and To Kau Wan (near Toll Plaza of NLH) (see Figure 5.2b). The total capacity of these 2 concrete batching plants is 3,600m³/day and are located at more than 2 km from the existing ASRs in Tung Chung and Airport Island. In addition, these concrete batching plant are controlled under the Specified Process and hence sufficient mitigation measures would be implemented to control the emission of dust. The Contractor is also required to demonstrate by calculation that the design of his concrete batching plant would not cause unacceptable impacts. A list of the mitigation measures to be implemented by the contractor is given in Section 5.5.7. Hence, the impacts from these concrete batching plants would have insignificants cumulative impacts and not be quantified in this EIA.

5.5.2.7 There will be a maximum of 2 barges operating at the barging point to the south of Scenic Hill at any one time. Good site practices including the following would be implemented.

a. All road surface within the barging facilities will be paved.

b. Dust enclosures will be provided for the loading ramp.

c. Vehicles will be required to pass through designated wheels wash facilities.

d. Continuous water spray at the loading points.

5.5.2.8 These good site practices would be able to reduce the generation of dust at barging point by at least 90%.

5.5.3 Assessment Methodology

5.5.3.1 Dust impact assessment will be undertaken using the Fugitive Dust Model (FDM) as approved by USEPA and EPD. It is a well-known Gaussian Plume model designed for computing air dispersion model for fugitive dust sources. Modelling parameters including dust emission factors, particles size distributions, surface roughness, etc are referred to in EPD’s “Guideline on choice of models and model parameters” and USEPA’s AP-42. The density of dust will be assumed to be 2.5g/m³. The 5-year mean of the annual averaged TSP concentration will be taken as the background concentration. According to EPD’s monitoring data for Tung Chung Station, the 5-year average 1-hr TSP concentration is 71ug/m³ and this would be taken as the background concentration for fugitive dust modelling.

5.5.3.2 During daytime working hours (7am to 7pm), it is assumed that dust emissions would be generated from all dust generating activities and site erosion. Subject to the need of construction work at night-time and on weekend/holiday, it is assumed that dust emissions would only be generated from site erosion during night-time non-working hours (7pm to 7am of the next day).

5.5.3.3 The worst-case 1-hour, worst-case 24-hour average and annual TSP concentrations will be calculated based on real meteorological data (for Year 2007) on wind direction, wind speed, temperature and stability collected from the nearest weather station, the Chek Lap Kok Airport meteorological station.

5.5.3.4 Fugitive dust modelling will be conducted at heights 1.5m above local ground level. Since all the dust generating sources are at ground level, this assessment height would represent the worst-case scenario. Both the unmitigated and mitigated scenarios for the project will be presented. The following parameters had been adopted in the FDM model.

Table 5-6 Summary of Particles Size Distribution

Activities

Average value of particle size range^[1]

1.25um

3.75um

7.5um

12.5um

22.5um

· Heavy construction activities including filling, land clearing, ground excavation, cut and fill operations, construction of the facilities

· Wind Erosion

· Loading / unloading at barging points and surcharge / stockpile

7.2%

19.9%

20.3%

17.6%

35.1%

[1] S13.2.4.3 of USEPA AP-42

5.5.3.5 The concurrent construction of TMCLKL, HKBCF, LLP, etc have been included in the cumulative assessment. It should be noted that the marine viaduct section of HKLR and TMCLKL would mainly be viaduct structure and there would not be any major excavation. Similarly, the slope cutting and realignment of Cheung Tung Road under TMCLKL project are relatively small scale and more than 2 km from the existing ASRs in Tung Chung. Hence, it is anticipated that the cumulative dust impacts caused by the slope work, road realignment of Cheung Tung Road, and marine viaduct section of HKLR and TMCLKL would not be significant.

5.5.4 Assessment Results - “Unmitigated” Scenario

5.5.4.1 The maximum predicted 1-hour, 24-hour and annual TSP levels for construction of and other concurrent projects are summarised in Table 5-7.

5.5.4.2 The maximum predicted TSP hourly concentration is 2,443µg/m³ at the planned CAD Headquarters. These predicted concentrations have exceeded the 1-hr TSP criterion. The 24-hr concentration and the annual concentration for some ASRs also exceed the respective criteria.

Table 5-7 Maximum Predicted TSP concentrations under the “Unmitigated” scenario

		Concentration Unmitigated Scenario, ug/m³
ASR	Description	1-hr ^[1]	24-hr ^[2]	Annual average ^[3]
A87	AsiaWorld-Expo	2,218	235	85
A85	Hong Kong SkyCity Marriott Hotel	2,257	230	87
A82	SkyCity Nine Eagles Golf Course	2,018	233	92
A102	Terminal 2 Sky Plaza	2,066	371	99
P12	Planned CAD Headquarters Site (Roadside)	2,443	455	110
A79	CNAC Tower	1,704	253	93
A71	Cathay Pacific City	1,741	260	82
A67	Aviation Security Company Limited	918	145	76
A2	Caribbean Coast Block 1 - BCF Facade	901	182	75
A30	LeBleu Deux	815	136	75
A59	Ma Wan Chung	574	112	74

Notes

[1] An hourly averaged TSP concentration of 500µg/m³ should not be exceeded

[2] A 24-hour averaged TSP concentration of 260µg/m³ should not be exceeded

[3] An annual averaged TSP concentration of 80µg/m³ should not be exceeded

[4] Bold figures indicate the predicted TSP levels has exceeded EPD’s standards

5.5.5 Assessment Results - “Mitigated” Scenario

5.5.5.1 The unmitigated TSP concentrations in Table 5-7 above are high at some ASRs. However, under a good site practice with regular watering, dust suppression could be achieved. In accordance with USEPA AP-42, watering twice a day could generally reduce dust emission by half and hence the dust concentration by 50%. Hence, on the same basis, watering 4 times a day would achieve a dust removal efficiency of 75% (ie 100% - 100%/4). Similarly, watering 8 times a day would achieve a dust removal efficiency of 87.5% (ie 100% - 100%/8). In addition, using aggregates to pave the haul roads would also help to mitigate the dust generation. Assessment results indicate that the following watering measures is required to control the fugitive dust impacts:

· 8 times / day along within all work sites (an dust removal efficiency of 87.5%).

5.5.5.2 With the above watering throughout the construction phase, the 1-hour, 24-hour and annual TSP levels are predicted as shown in the table below. Details of the assessment results are given in Appendix 5B and the contours are given in Figure 5.3.

Table 5-8 Maximum Predicted TSP concentrations under the “Mitigated” scenario

		Concentration Mitigated Scenario, ug/m³
ASR	Description	1-hr ^[1]	24-hr ^[2]	Annual average ^[3]
A87	AsiaWorld-Expo	339	93	73
A85	Hong Kong SkyCity Marriott Hotel	344	92	73
A82	SkyCity Nine Eagles Golf Course	314	95	74
A102	Terminal 2 Sky Plaza	320	111	75
P12	Planned CAD Headquarters Site (Roadside)	367	122	76
A79	CNAC Tower	275	95	74
A71	Cathay Pacific City	280	96	73
A67	Aviation Security Company Limited	177	81	72
A2	Caribbean Coast Block 1 - BCF Facade	175	85	72
A30	LeBleu Deux	164	79	72
A59	Ma Wan Chung	134	77	71

Notes

[1] An hourly averaged TSP concentration of 500µg/m³ should not be exceeded

[2] A 24-hour averaged TSP concentration of 260µg/m³ should not be exceeded

[3] An annual averaged TSP concentration of 80µg/m³ should not be exceeded

[4] Bold figures indicate the predicted TSP levels has exceeded EPD’s standards

5.5.5.3 It should be noted that there would still be some minor construction works being conducted at the north of the HKBCF when the PCB is occupied in late 2015 and late 2016. Given that the minor construction work such as roadwork/structure/paving and the fact that the PCB would be air-conditioned, the filters of the air-conditioning system will serve to reduce construction dust to the remaining construction work. Hence, there would be insignificant fugitive dust impacts on the PCB.

5.5.5.4 Results indicate that by increasing frequency of watering as described above, the predicted cumulative 1-hour, 24-hour and annual TSP levels at all ASRs will comply with the TM-EIA and HKAQO. Hence, there would be no adverse cumulative dust impact caused. Pollution contours are presented in Figure 5.3. There will not be any air sensitive landuses exposed to impacts higher than the criterion. (For 1-hr TSP contours, it can been seen that the 500µg/m³ contour could encroach onto the existing CLP power substation and the electrical Switching Station which are not frequently manned and hence are not considered as sensitive to air quality. Part of the existing Marine Cargo Terminal berth would also be within the 500µg/m³ contour. However, the berth would stop operation once the construction work in the vicinity commences. Hence it is also not considered as sensitive to air quality.)

5.5.5.5 The construction dust impacts on ASR at LLP, MTR Siu Ho Wan Depot etc are assessed in the EIA for TMCLKL and have been confirmed to be comply with the legislative requirements and hence there is no residual construction dust impacts.

5.5.6 Recommended Mitigation Measures for Fugitive Dust

5.5.6.1 The Contractor is 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.

5.5.6.2 In accordance with the Air Pollution Control (Construction Dust) Regulation, the following dust suppression measures should also 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 extend 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.

5.5.6.3 For the barging facilities to the south of Scenic Hill, the following good site practice is required.

a. All road surface within the barging facilities will be paved.

b. Dust enclosures will be provided for the loading ramp.

c. Vehicles will be required to pass through designated wheel wash facilities.

d. Continuous water spray at the loading point.

5.5.6.4 By implementing these control measures and with good construction site practice, it is anticipated that dust impacts will be insignificant. It is recommended that the Contractor should undertake proper watering on all exposed spoil (with at least 8 times per day) throughout the construction phase.

5.5.6.5 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.

5.5.7 Recommended Mitigation Measures for Concrete Batching Plant

5.5.7.1 It should also be noted that in accordance with EPD’s Best Practicable Means Requirements for Cement Works (Concrete Batching Plant), the following mitigation measures should be adopted to prevent fugitive dust emissions for concrete batching plant:

· Loading, unloading, handling, transfer or storage of any dusty materials should be carried out in totally enclosed system;

· All dust-laden air or waste gas generated by the process operations should be properly extracted and vented to fabric filtering system to meet the emission limits for TSP;

· Vents for all silos and cement/pulverised fuel ash (PFA) weighing scale should be fitted with fabric filtering system;

· The materials which may generate airborne dusty emissions should be wetted by water spray system;

· All receiving hoppers should be enclosed on three sides up to 3m above unloading point;

· All conveyor transfer points should be totally enclosed;

· All access and route roads within the premises should be paved and wetted; and

· Vehicle cleaning facilities should be provided and used by all concrete trucks before leaving the premises to wash off any dust on the wheels and/or body.

5.5.8 Residual Impacts for Fugitive Dust

5.5.8.1 No residual dust impacts are expected with the adoption of appropriate dust mitigation measures, which will be implemented during the construction phase.

5.6 Operational Air Quality Assessment

5.6.1 Assessment Approach

5.6.1.1 Taking account of the air pollution control measures recommended in the Pearl River Delta Regional Air Quality Management Plan, which has been jointly drawn up by the governments of HKSAR and Guangdong in 2003 (see Section 5.6.3), the assessment for cumulative operational air quality has adopted the following approach:

· A regional model viz. Pollutants in the Atmosphere and the Transport over Hong Kong (PATH, a regional air quality prediction model developed by EPD) is used to quantify the impacts from various sources including those in Pearl River Delta Economic Zone (PRDEZ), the Hong Kong International Airport, power plants in HKSAR and roads beyond North Lantau etc.

· A near-field dispersion model is used i.e. CALINE4 for line sources to quantify the air quality impacts at local scale from open road emission and idling emission at HKBCF. Another near-field model ISCST3 is used to assess point and volume sources to quantify the air quality impacts at local scale from portals and ventilation buildings.

5.6.1.2 Appendix 5C illustrates the extent of the roads within the study area (i.e. in North Lantau) that would be included in near-field model. As discussed in Section 5.6.1.1, the pollutant dispersion from these roads has been predicted using CALINE4. Another model EmFAC-HK has been adopted to calculate the total vehicular tailpipe emission from roads within North Lantau.

5.6.2 Determination of Assessment Year

5.6.2.1 In accordance with the EIA Study Brief, the assessment year for air pollution impacts shall be calculated based on the highest emission strength from the project within the next 15 years upon commencement. The selected assessment year should therefore represent the highest emission scenario for HKLR and other proposed roads under HKBCF.

5.6.2.2 Given the operation nature of the project, NO₂ is the pollutant of primary concern. The worst assessment year has therefore been determined based on the highest total NO_x emission scenario using the EmFAC–HK. The approach for EmFAC-HK modelling is presented in Section 5.6.10.

5.6.2.3 Traffic forecast for 2015, 2016, 2021 and 2031 have been conducted, which has been submitted to TD and without any adverse comments. Sensitivity tests have therefore been undertaken to examine the worst case scenario for the following selected years:

· Year 2015 – HKLR commissioning year and HKBCF Phase 1 commissioning year;

· Year 2016 - HKBCF Phase 2 commissioning year;

· Year 2021 - Intermediate year between 2016 and 2031; and

· Year 2031 - 15 years after HKBCF Phase 2 commissioning.

5.6.2.4 Results for the above 4 scenarios are compared in the following table. It can therefore be concluded that the highest emission scenario is Year 2031.

Table 5-9 Sensitivity Test for Determination of Assessment Year

	Year for Sensitivity Tests (Figures below are NOx emissions in terms of Tonne / day)
Emission Category	2015^[1]	2016	2021	2031
HKLR	0.2660	0.2812	0.3329	0.5237
HKBCF and Associated Roads
Cross-boundary	0.1060	0.1145	0.1307	0.1978
Local traffic	0.0528	0.0893	0.0853	0.0929
Idling Emission on HKBCF	0.0218	0.0211	0.0317	0.0572
Total	0.4466	0.5061	0.5806	0.8716

[1] The original sensitivity test was conducted for 2014. Subsequent to the sensitivity test, the HKLR commissioning year and the HKBCF Phase 1 commissioning year has been changed to 2015. Given the slight change from 2014 to 2015 and the fact that the emission factors for 2015 are slightly less than that for 2014, it is more conservative to use the emission for 2014. It is therefore considered that it would not change the assessment year as 2031.

5.6.3 Emissions within Pearl River Delta Economic Zone (PRDEZ)

5.6.3.1 The Study of Air Quality in the Pearl River Delta Region conducted in Year 2000 had recommended various mitigation strategies to control and improve the regional air quality problems. In December 2003, the governments of HKSAR and Guangdong jointly drew up the Pearl River Delta Regional Air Quality Management Plan, with a view to meeting the emission reduction targets recommended in the Study of Air Quality in the Pearl River Delta Region. The Pearl River Delta Air Quality Management and Monitoring Special Panel has also been set up under the Hong Kong/Guangdong Joint Working Group on Sustainable Development and Environmental Protection to follow-up on the tasks under the Management Plan.

5.6.3.2 A Mid-term Review Study on Pearl River Delta Regional Air Quality Management Plan was commissioned by EPD (of HKSAR Government) and the Guangdong Environmental Protection Bureau (GPEPB) in Nov 2006 to update the regional pollutant emission for 2003 and 2010 Control Scenario, as well as to review the effect of control measures committed by the governments. The updated data from this Mid-term Review Study forms the basis for projection of PRDEZ emission in this EIA.

5.6.3.3 In addition, the Guangdong Province government also prepared the 珠江三角洲環境保護規劃 in Jun 2006 which also outlined the plan to control and reduce their emission up to 2020. With such measures, the resulted 2020 PRDEZ emission data are significantly lower than the 2010 PRDEZ emission data from the Mid-term Review Study.

5.6.3.4 Given the best available emission inventory for 2010 from the Mid-Term Review and the 2020 inventory compiled from 珠江三角洲環境保護規劃, it is considered that a prudent approach would be to interpolate from these 2 sets of inventory to generate the 2015 inventory and to assume that the regional emission would then be capped within the assessment period of this project ie up to 2031. (Note: In accordance with the 珠江三角洲環境保護規劃, with the measures therein, the PRDEZ emission will in fact continue to reduce all the way to 2020. However, for a conservative assessment, it is assumed that the PRDEZ emission is capped at 2015 level as far as this EIA is concerned.) A summary of the 2031 PRDEZ emission inventory is given in Appendix 5D.

5.6.4 Emissions from Hong Kong International Airport

5.6.4.1 A review of the operation activities on the Chek Lap Kok Airport reveals that there are 6 key groups of emission sources, including

· Aircraft movements;

· Ground Support Equipment (GSE);

· Auxiliary Power Units (APUs);

· Engine Run-Up Facility;

· Fuel Tanks; and

· Aircraft Maintenance.

5.6.4.2 The respective stakeholders for the above-mentioned sources have been consulted to obtain relevant latest operation information. The key assumptions adopted to compile the emission inventory are described in the paragraphs below. The operation information provided by the airport operator (i.e. the Airport Authority) is summarised in Appendix 5E.

Aircraft Movements

5.6.4.3 Aircraft movements could be considered as comprising 4 main operation modes, viz. take-off, climb-out, final approach and idling/taxi-ing. Each mode would have different Emission Index (EI), fuel consumption rates and duration. The pollutant emissions from these modes would be a product of the EI, fuel consumption rates and the duration.

5.6.4.4 The latest operation information for aircraft movements including Landing-Takeoff Cycle (LTO), aircraft mix and the duration of idling/taxi-ing for 2020 (year when the airport would reach its capacity) had been collected from the airport operator (i.e. the Airport Authority).

5.6.4.5 Since there is no information on the EIs, fuel consumption rates and the duration for different types of aircrafts (except the taxi-ing and idling time), reference is made to international reference such as USEPA’s “Evaluation of Air Pollutant Emissions from Subsonic Commercial Jet Aircraft”, FAA’s “Emission and Dispersion Modelling System” and the ICAO Engine database.

5.6.4.6 The airport operator has also advised that the airport would reach its full operation capacity (in terms of passenger and cargo handling) by Year 2020, which is 20 years earlier than the assumed year of reaching capacity adopted in the New Airport Master Plan 1991 (NAMP 1991). It is therefore assumed that the pollutant emission after Year 2020 would remain the same as that predicted for Year 2020. The updated emission inventory is given in Appendix 5D.

Ground Support Equipment

5.6.4.7 Other than the emissions from aircrafts, the GSE (mostly diesel-driven) would also generate air pollutants. According to the information available, GSE include tractors, belt loaders, catering trucks etc. Information/data as regards typical load factors and operation duration for the GSE have been obtained from the airport operator.

5.6.4.8 The emission factors for GSE have been extracted from the FAA’s and EDMS’s emission database. Appendix 5D presents the predicted GSE emission for Year 2020 and it is assumed that the emission would be capped from 2020 onwards.

5.6.4.9 It is assumed that all the GSE would be manoeuvring within the apron area. Hence the emission from GSE would be modelled as an area source covering the entire apron area. The temporal profile for GSE emissions is assumed to be the same as that for aircraft emissions.

Auxiliary Power Units

5.6.4.10 Auxiliary power units (APUs) would also generate air pollutants. Information/data as regards typical load factors and operation duration for APUs have been obtained from the airport operator too. Reference has been made to the EDMS database for APUs for different types of aircrafts for Year 2020 (assumed to be capped to Year 2031; see Appendix 5D).

5.6.4.11 It is assumed that all the APUs would be manoeuvring within the apron area. Hence the emission from APUs would be modelled as an area source covering the entire apron area and at an elevated level to take account of thermal plume rise. The temporal profile for APU emissions is assumed to be the same as that for aircraft emissions.

Engine Run-Up Facility

5.6.4.12 The existing engine run-up facility is located in the western part of the airport island. Operation information is however not available. In order to conduct a more conservative assessment, it is assumed that all the aircrafts tested would be 747-400, and each test would consist of 5 LTO cycles. In addition, it is further assumed that there would be 3 times of testing each week. A summary of the predicted emission is given in Appendix 5D.

5.6.4.13 The facility would be modelled as an area source. And it is assumed that the temporal profile would be constant throughout the year.

Fuel Tanks

5.6.4.14 The existing fuel tank farm is located to the southeast corner of the Airport Island near the Scenic Hill, with a total of 9 fuel tanks. Three new tanks are being installed to the west of the existing fuel tank farm. All the tanks have fixed roofs and are freely vented.

5.6.4.15 Emissions from the total 12 no. fuel tanks have been estimated using the Emissions and Dispersion Modeling System (EDMS). The results indicate that the annual VOC emission from all fuel tanks would be 8 tonne for Year 2031 (see Appendix 5D). The fuel tank farms have been modelled as point sources. It is assumed that the temporal profile would be constant throughout the year.

Aircraft Maintenance

5.6.4.16 It is understood that the main sources of VOC from aircraft maintenance are the paint shops and the aircraft hangers. However, air extraction systems have been installed to extract the VOC to water scrubbers before discharging to the atmosphere. It is therefore anticipated that the VOC emission through the scrubbers should be insignificant. Hence the PATH model has not included any emissions from the aircraft maintenance facility.

5.6.5 Emissions from Power Stations within HKSAR

5.6.5.1 In accordance with the information from the power stations in HKSAR, about 28% of the electricity is currently generated from natural gas. It is also noted from their publication (eg annual reports) that they have plans to increase the utilisation of natural gas to 50% by early next decade. It is therefore considered reasonable to assume that, by the time of 2015, the utilisation rate of natural gas within HKSAR should have reached 50%. It is also assumed that after Year 2015, the emission would be capped at the same level as 2015. This should be an assumption on the prudent side, as the trend of increase in utilisation of natural gas ought not reverse after Year 2015. An estimate of the emission with a natural gas utilisation rate of 50% is given in Appendix 5D.

5.6.6 Industrial Sources within HKSAR

5.6.6.1 The emissions from other industrial sources have also been considered. Estimation has been made by projecting from the emission level for 2010 in the Mid-Term Review to the emission level for 2015. A summary of the industrial emission sources within HKSAR for 2031 is given in Appendix 5D.

5.6.6.2 Other specific emission sources have been updated based on their respective best available information. A summary of the specific industrial emission sources within HKSAR for 2031 is given in Appendix 5D. The assumptions for updating these specific industrial emission sources are given below:

Emission Group	Key Assumptions in Updating Emission Inventory
Ecopark	· Based on their approved EIA Report.
Integrated Waste Management Facilities	· According to the project proponent, there is no information as regards its implementation; hence it is not included in the emission inventory in this EIA.
Organic Waste Facilities	· Ditto.
Sludge Treatment Facility	· Based on their approved EIA Report (ref: EIA-155/2008)
Green Island Cement Facilities	· Based on their Specified Process Licence.

5.6.7 Marine Emission within HKSAR

5.6.7.1 In the original PATH model developed by EPD, the marine emission sources in Hong Kong were apportioned into 2 counties including:

Hong Kong Harbour	· Marine emissions from vessels within the Victoria Harbour
HK Waters	· Marine emissions from vessels from area beyond the Victoria Harbour

5.6.7.2 Marine emission inventory for the Control Scenario of Year 2010 in the Mid-term Review Study will be adopted as the basis for emission projection. The emission from marine vessels are apportioned into different categories including supporting ships, international ferry, river trade, ocean going vessels, anchorage and other ships based on the emission breakdown of the above-mentioned 2010 Control Scenario.

5.6.7.3 For emission projection, reference has been made to the Study on Hong Kong Port – Master Plan 2020 – Final Strategic Environmental Assessment – Part 2 (Port 2020 Study). Accordingly, the growth factors tabulated below have been adopted.

Table 5-10 Growth Factor for Marine Vessels from 1997 to 2020

		% Increase from Yr 1997
Emission Source		Ocean Going Ships	Ferries	River Trades	Tug & Tow
Hong Kong harbour	1997 – 2020 (as in Port 2020 Study)	99	0	145	-62
	Equiv annual growth rate (assuming linear growth)	3.04	0.00	3.97	-4.12
Hong Kong waters	1997 – 2020 (as in Port 2020 Study)	162	0	145	-62
	Equiv annual growth rate (assuming linear growth)	4.28	0.00	3.97	-4.12
Container Terminal CT 1-9	1997 – 2020 (as in Port 2020 Study)	113.00	* TEU trend
	Equiv annual growth rate (assuming linear growth)	3.34
Container Terminal CT 10	1997 – 2020 (as in Port 2020 Study)	182.00	* TEU trend
	Equiv annual growth rate (assuming linear growth)	4.61

Note:

(1) Data (with CT10 at Tsing Yi) are extracted from Study on Hong Kong Port – Master Plan 2020 – Final Strategic Environmental Assessment – Part 2 (Port 2020 Study)

5.6.7.4 The emission for the assessment year 2031 can then be determined based on the 2010 emission and the equivalent annual growth factors; the result is presented in Appendix 5D.

5.6.8 Vehicular Emissions within HKSAR beyond those on Lantau

5.6.8.1 For roads beyond Lantau, the emissions are predicted using EPD’s EmFAC-HK model which takes into account the exhaust technology, number of trips, different vehicle classes, different speed fraction etc of the entire Hong Kong region. The vehicle-kilometer-travelled (VKT) were forecast by Arup’s in-house Territory Transport Model (accepted by Transport Department).

5.6.8.2 Whereas detailed assessment on the traffic for roads in Lantau/Airport has been conducted under the traffic impact assessments for HKLR and HKBCF, the traffic for roads beyond Lantau can only make reference to territory-wide traffic forecast. For these ready beyond Lantau, the territory wide traffic forecast is only available for Year 2030, though all the major planned highway infrastructure projects have been included. It is also considered that the territory wide traffic for 2031 would be very similar to that of 2030. Moreover, any impacts due to these “beyond-Lantau roads” on the sensitive receivers relevant to the EIAs of HKLR & HKBCF ought to be relatively minor. Hence the 2030 territory-wide traffic figures are considered to be acceptable to assess the impacts due to these “beyond-Lantau roads”. A summary of the projected 2030 (equivalent to 2031) vehicular emission from HK roads other than those on Lantau is given in Appendix 5D.

5.6.9 Other Emission Sources

5.6.9.1 The emissions from other emission sources (eg Non-Road mobile sources, VOC containing sources etc) have also been considered by projecting from the emission level for 2010 in the Mid-Term Review to the emission level for 2015. A summary of the other emission sources within HKSAR for 2031 is given in Appendix 5D.

5.6.10 Road Emission within Lantau and Airport Island

5.6.10.1 For road emissions within Lantau/Airport for Year 2031, EmFAC-HK was used to calculate the vehicular tailpipe emission instead of using the traditional fleet average emission factors. EmFAC-HK (ref http://www.epd.gov.hk /epd /english /environmentinhk /air /guide_ref /emfac.html) is a more versatile model giving more refined estimates, and is appropriate for the current study from an air quality assessment point of view. It can readily calculate the vehicular emissions for different projected scenarios for different future years, while the traditional fleet average emission factors commonly used in other projects can only provide emission factors up to Year 2011 and cannot take into account the implementation of fuel with better quality.

5.6.10.2 In accordance with the current legislation, cross-boundary vehicles must go through the vehicle-registration process in Hong Kong. In addition, all motor vehicles seeking first registration in Hong Kong must comply with the requirements of the Air Pollution Control (Vehicle Design Standards) (Emission) Regulations. Since there is no program on policy review, it is assumed that the first registration policy is still applicable for this assessment. This implies that cross-boundary vehicles (mainly on the HKLR and the HKBCF) will perform as Hong Kong vehicles of similar types as far as tailpipe emission is concerned.

5.6.10.3 According to the latest implementation programme of the emission standards for diesel vehicles, the following emission standards should be adopted for calculation of emissions from diesel vehicles registered in Hong Kong irrespective of whether they need to travel to/from Macao and Mainland China:

(i) Diesel vehicles < 3.5 tonnes: Euro IV by 2007

(ii) Diesel vehicles > 3.5 tonnes: Euro IV by 2007, Euro V by 2010

5.6.10.4 A recently published diesel fuel analysis result by the Macao Authority shows that their fuel quality is very close to the current fuel in Hong Kong (http://www.ambiente.gov.mo/tchinese/08/2005/05.asp). In addition, Mainland China Authorities announced to implement Euro IV and V standards (for diesel fuel) by 2010 and 2012 respectively (http://sysadm.blog.51cto.com/180447/30805 and http://www.chinarhy.com/chinarhy/2008/200810/2008-10-22/2563.html). The fuel properties will also be in line with the implementation of these standards. Therefore the maximum sulphur content will be 0.005% and 0.001% by 2010 and 2012 respectively.

5.6.10.5 In consideration of the above, it should be reasonable to assume that cross-boundary vehicles will perform similarly to Hong Kong vehicles in terms of pollutant emission. All vehicles have therefore been considered as Hong Kong vehicles in this assessment.

5.6.10.6 Other developments in the Concept Plan of Lantau, such as Tung Chung East Development, Tung Chung West Development, Lantau Logistics Park, tourism node at Sunny Bay, etc. have already been taken into account in developing the traffic data. The traffic profile is determined from the existing Annual Traffic Census (ATC) data, supplemented by the results of traffic survey.

5.6.10.7 The air quality assessment under this EIA has also taken into account other factors including the vehicle population, hourly temperature and humidity, traffic speed etc. Appendix 5F-1 presents the key assumptions for the EmFAC modelling and Appendix 5F-2 gives the estimation of the vehicular emission factors for NO_x and RSP (including the composite vehicle emission factors for each road link).

5.6.11 Vehicular Emission Kiosks and Loading / Unloading Bays

5.6.11.1 As discussed in Section 5.3.2, vehicular emission at kiosks and loading / unloading bays also need to be considered. Considerations have been given to the number of vehicles at the kiosks and the loading / unloading bays. A summary of the estimated emissions at 2031 is given below (see Appendix 5G).

Table 5-11 Summary of Emission at Kiosks and Loading / Unloading Bays

	Emission Factor, (g/hr)
Activities	NO_x	RSP
*Kiosks*
Car (Inbound)	270.1	Negligible
Car (Outbound)	178.1	Negligible
Goods Vehicle (Inbound)	438	17
Goods Vehicle (Outbound)	370	14
Bus (Inbound)	47	2
Bus (Outbound)	40	2
*Loading Bay*
Bus (Inbound)	1247	48
Bus (Outbound)	1056	41
*Unloading Bay*
Bus (Inbound)	312	12
Bus (Outbound)	264	10

5.6.12 Vehicular Emission from TMCLKL

5.6.12.1 The vehicular emission from TMCLKL is provided by the EIA Consultant of TMCLKL. A summary of their emission factors is given in Appendix 5H.

5.6.13 Other Vehicular Emission

5.6.13.1 The traffic forecast has included all the induced traffic from planned developments such as LLP, Tung Chung East and West Future Developments. In addition, the vehicular emission from the 2 ventilation buildings for the HZMB Main Bridge have also been included for assessing the cumulative air quality impacts.

5.6.14 Dispersion Modelling Methodology

5.6.14.1 The PATH model was previously used in the Study of Air Quality in the Pearl River Delta Region (Consultancy Agreement no. CE 106/98), in which regional air quality was predicted up to Year 2015.

5.6.14.2 There are three core modules in the PATH model, namely:

· MM5 - Conditioning for Meteorology, Terrain, Landuse;

· EMS-95 - Emission Inventory;

· SAQM - Pollutants Transport & Chemistry Modelling.

Detailed descriptions of these modules are given in Technical Annex 7 of the CE 106/98 Study.

5.6.14.3 Input for MM5 Module – A complete set of MM5 Module data (at 1.5km grid) for 2003 has been compiled and provided by EPD. This is the best available set of meteorological information for the entire Pearl River Estuary and HKSAR for PATH modelling, satisfying the requirement under Annex B-1 of the EIA Study Brief. This set of data has been adopted for assessing the impacts for the assessment year.

5.6.14.4 Input for EMS-95 Module – EMS-95 consists of 5 main emission modules for point, area, biogenic, motor vehicle and marine sources. Point and area emission data are processed through EMS-95. The resultant output comprises hourly emission files, spatially allocated over the model domain grids, and then speciated i.e. processed in a suitable format for use in the air quality model emission preprocessor.

5.6.14.5 The steps involved in running EMS-95 consists of running firstly the grid definition model, followed by the point, area and biogenics mode, and then the speciation model.

5.6.14.6 SAQM Module – The output data from MM5 and EMS-95 are processed through the SAQM module. The SAQM model time-step is set to one hour, and is run in a one-way nested mode. The boundary and initial conditions are derived from the largest 40.5 km domain and used as input to the 13.5 km domain, and subsequently to 4.5km and 1.5km domains.

5.6.15 Prediction of Open Road Emission

5.6.15.1 Whereas the traffic emissions for roads beyond Lantau are covered by the PATH modelling already, the traffic emissions for roads in Lantau/Airport are assessed separately by near-field modelling. The USEPA approved line source air dispersion model, CALINE4, developed by the California Department of Transport is used to assess the dispersion of traffic emissions impact from existing and planned roads in the Lantau/Airport area.

5.6.15.2 The hourly emission rates for each vehicle class (in gram per mile per vehicle) are obtained by dividing the emissions for the four road categories calculated in the EmFAC-HK by the total vehicle travelled miles. The composite emission factors in CALINE4 model are then calculated, as illustrated in Appendix 5G.

5.6.15.3 Grid-specific composite real meteorological data are adopted, including:

· Relevant temperature, wind speed, direction and mixing height from the MM5 model; and

· Stability class from a separate model PCRAMMET.

5.6.15.4 Meteorological data were extracted from PATH model for input into the CALINE4 and ISCST3 models, and processed by capping the mixing height to 129m as per the real meteorological data. As regards the treatment of calm hours, the approach of the "Guideline on Air Quality on Air Quality Models Version 05" has been adopted.

5.6.15.5 Ozone Limiting Method (OLM) was adopted for conversion of NO_x to NO₂, using the predicted O₃ and NO₂ levels from PATH.

5.6.15.6 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. The surface roughness and the wind standard deviation are estimated in accordance with the “Guideline on Air Quality Models (Revised), 1986”, as summarized in the table below.

Table 5-12 Summary of Surface Roughness and Wind Standard Deviation

Period / Location/ Parameters		Assumptions
Tung Chung	Surface roughness (cm)	370
	Wind standard deviation (degrees)	1) 43 for A & B Stability Classes; 2) 33 for C Stability Class; 3) 24 for D Stability Class; 4) 14 for E Stability Class; and 5) 7.2 for F Stability Class.
Lantau & Airport Island	Surface roughness (cm)	50
Lantau & Airport Island	Wind standard deviation (degrees)	1) 29 for A & B Stability Classes; 2) 22 for C Stability Class; 3) 16 for D Stability Class; 4) 9.5 for E Stability Class; and 5) 5 for F Stability Class.

5.6.15.7 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 will be set to 10m in the CALINE4 model as the worst-case assumption.

5.6.15.8 For barriers along roads (eg the existing noise barriers along the NLH near existing Tung Chung area see Figure 5.4g), the line source has been modelled at the tip of the barrier and the mixing width will be limited to the actual uncovered road width. The road type of the concerned section was set to the “fill” option.

5.6.15.9 As regards the dispersion of emission from kiosks and loading/unloading bays on HKBCF, the Parking Lot mode in the CALINE4 would be used to simulate the dispersion.

5.6.16 Prediction of Portal and Ventilation Building Emissions

5.6.16.1 The USEPA approved ISCST3 model was adopted for modelling of emission from portals and ventilation buildings. Similar to the assessment of open road emission, the ISCST3 model has adopted the grid-specific composite real meteorological data as that adopted for CALINE4 modelling. The tunnels and portals in the proposed project include the following:

Table 5-13 Summary of Tunnel Ventilation

Tunnel	Length	Ventilation	Portal Dim	Other Details for VB
*HKLR*
Under Scenic Hill (See Figures 5.4a to f)	1.1km	Ventilation Building (70% pollutants discharged from vent building, 30% via portals)	In-Bound Height : 5.85m (above local ground) Width : 12m Out-Bound Height : 5.85m Width : 15.6m	Flow rate : 133m³/s Discharge vel : 5m/s Height above local road : 5m Diameter: 5.8m
*HKBCF*
Road link (with tunnel section) from HKBCF to Airport (See Figures 5.4a to f)	~0.9km	Horizontal Jet Fans (100% pollutants discharged from tunnel exit)	Height : 7m (above local ground) Width : 11.3m	(Not required for modelling)

Note: Details of the ventilation building for TMCLKL are separately provided by the EIA Consultant of TMCLKL (see Appendix 5I).

5.6.16.2 For tunnels, the effect of portal emission will be considered. The hourly emission rate will be obtained by multiplying the emission strength (g/km/veh) by the products of traffic flow (veh/hr) and tunnel/enclosure length (km). The emission split between the tunnel portal and ventilation building will be 30% / 70% according to the latest design. For tunnels using jet fans, all the emission would be assumed at the exit of the tunnel.

5.6.16.3 The portal emission was assessed in accordance with the PIARC guideline assuming a jet effect to discharge to the first 100-250m of the open road section in the direction of the vehicular movements in 10 sources, with 2/3 of the total emission strength for the first five sources and 1/3 of the total emission strength for the remaining 5 sources. The emission was then modeled as volume sources by ISCST3. Appendix 5I presents the calculations for the tunnel portal emission.

5.6.16.4 Emissions from the ventilation buildings (including those for HKBCF, TMCLKL, HZMB Main Bridge) were assessed by the ISCST3 model as point sources.

5.6.16.5 Ozone Limiting Method (OLM) was used for conversion of NOx to NO₂ based on the O₃ level from PATH direct (i.e. no residual O₃ is considered after vehicular emission interaction). As a conservative approach, OLM is applied separately to the following groups of emission sources:

· Open roads;

· West bound portal and ventilation building of the tunnel under Scenic Hill;

· Eastbound portal of the tunnel under Scenic Hill;

· Tunnel portals for the road link (with tunnel section) from HKBCF to Airport;

· Southern tunnel portal for the southern landfall of TMCLKL;

· Ventilation building for the southern landfall of TMCLKL;

· Tunnel portals and ventilation building of the HZMB Main Bridge.

5.6.16.6 The ventilation design of the tunnels for HKLR and HKBCF would be designed to meet EPD’s guidelines for Air Quality Inside Tunnel.

5.6.17 Prediction of Cumulative Air Quality Impacts

5.6.17.1 The cumulative pollutant concentrations are computed by combining the predicted concentration from PATH, CALINE4 and ISCST on an hourly basis. All the predictions including maximum 1-hour, 24-hour average and annual average for NO₂ and RSP from 1.5m to 20m above local ground or higher level for some ASRs are given in Appendix 5J. A summary of these predictions at the worst hit levels is presented in the tables below.

Table 5-14A Predicted Maximum 1-hour Concentrations

Locations	NO_2,ug/m³
Sham Wat (A98 – A99)	214 – 218
Sha Lo Wan (A93 – A96)	232 - 246
San Tau Area (A90 – A92)	212 – 228
Ma Wan Chung (A59, A60 – A66)	197 - 202
San Shek Wan (A97)	219
Tung Chung Town - South of NLH (A41 – A58, P3)	195 - 243
Tung Chung Town – North of NLH (A1 – A40, A100 – A101, P4 – P6)	192 - 206
Airport Island (A67 – A89, A102 –- A106, P12 – P13)	203 - 271
Tung Chung East Further Development (P1 – P2)	191 - 201
Tung Chung West Further Development (P7 – P11)	200 - 210
AQO	300
% of AQO	90
Margin below AQO	29

Table 5-14B Predicted Maximum Daily Concentrations

Locations	NO_2,ug/m³	RSP, ug/m³
Sham Wat (A98 – A99)	96 - 110	89 - 91
Sha Lo Wan (A93 – A96)	130 - 134	95 - 96
San Tau Area (A90 – A92)	108 - 109	90
Ma Wan Chung (A59, A60 – A66)	100 - 105	90
San Shek Wan (A97)	110	92
Tung Chung Town - South of NLH (A41 – A58, P3)	103 - 119	90 - 92
Tung Chung Town – North of NLH (A1 – A40, A100 – A101, P4 – P6)	93 - 127	91 - 92
Airport Island (A67 – A89, A102 –- A106, P12 – P13)	110 - 131	90 - 96
Tung Chung East Further Development (P1 – P2)	94 - 107	91 - 92
Tung Chung West Further Development (P7 – P11)	99 - 109	89 - 91
AQO	150	180
% of AQO	89	53
Margin below AQO	16	84

Table 5-14C Predicted Annual Concentrations

Locations	NO_2,ug/m³	RSP, ug/m³
Sham Wat (A98 – A99)	22 - 26	43 - 45
Sha Lo Wan (A93 – A96)	44 - 47	47
San Tau Area (A90 – A92)	31 - 33	45
Ma Wan Chung (A59, A60 – A66)	23 - 25	44
San Shek Wan (A97)	27	45
Tung Chung Town - South of NLH (A41 – A58, P3)	26 - 54	44 - 47
Tung Chung Town – North of NLH (A1 – A40, A100 – A101, P4 – P6)	26 - 43	44 - 46
Airport Island (A67 – A89, A102 –- A106, P12 – P13)	34 - 51	45 - 48
Tung Chung East Further Development (P1 – P2)	24 - 27	44
Tung Chung West Further Development (P7 – P11)	25 - 36	44 - 46
AQO	80	55
% of AQO	68	87
Margin below AQO	26	7

5.6.17.2 It can be seen from the above tables that the predicted pollutant concentrations at all the representative ASRs do satisfy the Air Quality Objectives.

5.6.17.3 For the ASRs on the eastern coast of Tung Chung East Future Development, LLP and the MTR Siu Ho Wan Depot, the EIA Report for TMCLKL has confirmed that all the existing and planned receivers would comply with the relevant criteria and there are no residual air quality impacts.

5.6.17.4 In order to identify any potential landuse constraints along the alignment of HKLR and in the vicinity of the HKBCF (within area more influenced by HKLR and HKBCF), the use of pollution contours has been considered.

5.6.17.5 For the HKLR section along the airport channel, there are no planned sensitive uses on airport island. The village houses to the south of the alignment include San Shek Wan, Sha Lo Wan and San Tau would mainly retain as village type developments and representative ASRs have been assessed. Results indicated that all the predicted concentrations are well within the criteria. The receivers are also about at least 100m far away from the HKLR. Hence, it is considered that pollution contours are not required.

5.6.17.6 For the HKLR alignment along the eastern coast of airport island and near to the HKBCF, there would be some planned developments closer to the project boundary. These planned developments include the CAD Headquarter and other landuse to the south of AsiaExpo. Pollution contours would therefore be useful for identify any landuse constraints. Further analysis of the results for discrete ASRs suggests that, for the maximum predicted RSP concentrations (for 24-hr average and annual) are dominated by the background concentration (up to 98%) instead of the contribution from the traffic on the roadwork. For the annual NO₂, the predicted concentration is relatively low, only constitute about 28-68% of the AQO. It is therefore considered that contours for RSP and annual NO₂ would not provide useful information for identifying landuse constraints. Hence, pollution contours would only be generated for 1-hr NO₂ and 24-hr NO₂.

5.6.17.7 For the Tung Chung area, analysis has revealed that higher concentrations are predicted for the ASRs closer to the NLH. Receivers away from NLH would be subject to much lower pollution concentrations. Due to the influence of the emission from the airport, the predicted pollution concentrations for ASRs such as the Citygate would be slightly higher than the developments to the east of the Tung Chung New Town. Hence, it is considered appropriate to have the contours for the area near Citygate. Similar to the situation for ASRs along the eastern coast of the airport island, only 1-hr and 24-hr NO₂ pollution contours would be presented.

5.6.17.8 The pollution contours on the concerned areas are presented in Figures 5.5a to c. It can be seen from these contours that other than a small portion of the planned highway maintenance area along the eastern coastline of airport island (reclaimed under the HKLR), the air quality impacts caused by HKLR and HKBCF would not impose any constraints and the neighbouring landuse. Since the planned highway maintenance area along the eastern coastline would not have any air sensitive uses, it would not impose any landuse constraints.

5.7 Conclusion

5.7.1 An air quality impact assessment has been conducted for both the construction and operational phases. The fugitive dust assessment for the construction phase has concluded that 8 times/day watering in all works areas would be required to control the fugitive dust impact.

5.7.2 For the assessment of operational phase air quality, a combination of regional wide model (PATH) and near field dispersion models (CALINE4 and ISCST3) has been used. This approach allows a more realistic prediction taking into consideration of the regional meteorological patterns, terrain effect and complex photochemical reactions. The PATH model also takes into account the Pearl River Delta Regional Air Quality Management Plan drawn up by the HKSAR and the Guangdong Provincial Government.

5.7.3 Sensitivity tests have been undertaken to identify the highest emission scenario from this Project, given the combination of vehicular emission factors and the projected traffic flow. It is concluded that the worst-case assessment scenario is Year 2031. Emissions for various pollutant sources have therefore been updated for the assessment year.

5.7.4 For open road emissions within North Lantau, the dispersion was modelled by CALINE4. EmFAC-HK model was adopted to calculate the vehicular tailpipe emission, taking into account the latest implementation program of the emission standards for diesel vehicles and fuel quality in Macao and Mainland China.

5.7.5 The effect of emission from portals and ventilation buildings has been modelled using ISCST, taking the length of each tunnel and its ventilation scheme into account.

5.7.6 The results show that the predicted cumulative pollution concentrations at all identified ASRs will comply with the Air Quality Objectives. There will be no landuse constraints. Hence, it is concluded that there will not be any residual air quality impacts.