3 Air Quality Impact

3.1 Introduction

3.1.1.1 This section presents the assessment on potential air quality impacts on the air sensitive receivers (ASRs) arising from construction and operation of the Project. Assessment has been conducted in accordance with the criteria and guidelines as stipulated in Annex 4 and Annex 12 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM) as well as the requirements given in Clause 3.4.4 of the EIA Study Brief (No. ESB-343/2021).

3.2 Environmental Legislation, Standards and Guidelines

3.2.1.1 The criteria for evaluating air quality impacts and the guidelines for air quality assessment are laid down in Annex 4 and Annex 12 of the EIAO-TM.

3.2.2 Air Quality Objectives & Technical Memorandum on EIA Process

3.2.2.1 The Air Pollution Control Ordinance provides the statutory authority for controlling air pollutants from a variety of sources. The Hong Kong Air Quality Objectives (AQOs), which stipulate the maximum allowable concentrations over specific periods for typical pollutants, should be met. The prevailing AQOs are listed in Table 3.1.

Table 3.1 Hong Kong Air Quality Objectives

Pollutants	Averaging Time	Concentration Limit (µg/m^3)^[1]	Number of Exceedance Allowed per Year
Respirable Suspended Particulates (RSP or PM10) ^[2]	24-hour	100	9
	Annual ^[4]	50	Not applicable
Fine Suspended Particulates (FSP or PM2.5) ^[3]	24-hour	50	35^[5]
	Annual ^[4]	25	N/A
Nitrogen Dioxide (NO2)	1-hour	200	18
	Annual ^[4]	40	N/A
Sulphur Dioxide (SO2)	10-min	500	3
	24-hour	50	3
Carbon Monoxide (CO)	1-hour	30,000	0
	8-hour	10,000	0
Ozone	8-hour	160	9
Lead (Pb)	Annual^[^4]	0.5	NA

Notes:

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

[2] Suspended particulates in air with a nominal aerodynamic diameter of 10µm or smaller.

[3] Suspended particulates in air with a nominal aerodynamic diameter of 2.5µm or smaller.

[4] Arithmetic mean

[5] The number of allowable exceedances of 18 days per calendar year as the benchmark for conducting air quality impact assessment under new Government Project Environmental Impact Assessment studies.

3.2.3 Air Pollution Control (Construction Dust) Regulation

3.2.3.1 Notifiable and regulatory works are under the control of Air Pollution Control (Construction Dust) Regulation. Notifiable works include site formation, reclamation, demolition, foundation and superstructure construction for buildings and road construction. Regulatory works include building renovation, road opening and resurfacing, slope stabilisation, and other activities including stockpiling, dusty material handling, excavation, concrete production, etc. This Project is expected to include notifiable works (foundation and superstructure construction and demolition) and regulatory works (dusty material handling and excavation). Contractors and site agents are required to inform Environmental Protection Department (EPD) and adopt dust reduction measures to minimize dust emission, while carrying out construction works, to the acceptable level.

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

3.2.4.1 The Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation came into effect on 1 June 2015. Under the Regulation, Non-road mobile machinery (NRMMs), except those exempted, are required to comply with the prescribed emission standards. From 1 September 2015, all regulated machines sold or leased for use in Hong Kong must be approved or exempted with a proper label in a prescribed format issued by EPD. Starting from 1 December 2015, only approved or exempted NRMMs with a proper label are allowed to be used in specified activities and locations including construction sites. The Contractor is required to ensure the adopted machines or non-road vehicle under the Project could meet the prescribed emission standards and requirement.

3.2.5 Air Pollution Control (Fuel Restriction) Regulation

3.2.5.1 The Air Pollution Control (Fuel Restriction) Regulation was enacted in 1990 to impose legal control on the type of fuels allowed for use and their sulphur contents in commercial and industrial processes to reduce sulphur dioxide (SO₂) emissions. In June 2008, the Regulation was amended to tighten the control requirements of liquid fuels. The Regulation does not apply to any fuel-using equipment that is used or operated in premises used solely as a dwelling or is used or operated in or on a vessel, motor vehicle, railway locomotive or aircraft.

3.2.6 Development Bureau Technical Circular (Works)

3.2.6.1 The Development Bureau Technical Circular (Works) No. 13/2020 Timely Application of Temporary Electricity and Water Supply for Public Works Contract and Wider Use of Electric Vehicles in Public Works Contracts is one of the environmental guidelines on timely application of temporary electricity and wider use of electric vehicles in public works contract. Development Bureau Technical Circular (Works) No. 1/2015 Emissions Control of Non-Road Mobile Machinery in Capital Works Contracts of Public Works also requires that no exempted generators, air compressors, excavators and crawler cranes shall be allowed in the new capital works contracts of public works (including design and build contracts) with an estimated contract value exceeding $200 million, unless is at the discretion of the Architect/Engineer considering no feasible alternative.

3.2.7 Practice Note on Control of Air Pollution in Vehicle Tunnels

3.2.7.1 The Practice Note on Control of Air Pollution in Vehicle Tunnels prepared by EPD provides guidelines on control of air pollution in vehicle tunnels. Guideline values on tunnel air quality are presented in Table 3.2.

Table 3.2 Tunnel Air Quality Guidelines

Pollutant	Averaging Time	Maximum Concentration
		µg/m^3 ^[1]	ppm
Carbon Monoxide (CO)	5 minutes	115,000	100
Nitrogen Dioxide (NO2)	5 minutes	1,800	1
Sulphur Dioxide	5 minutes	1,000	0.4

Notes:

[1] Measured at 298K and 101.325kPa

3.3 Description of Environment

3.3.1.1 The Project covers Tsuen Wan area and Kwai Tsing area. The northern boundaries of the Project are at TWR near Chai Wan Kok Interchange, while the southern boundaries of the Project are at TWR near Kwai Tsing Interchange. The Project site is located in developed areas surrounded by a combination of transport infrastructure, residential premises, industrial / commercial buildings and government facilities. Existing air quality in the study area is affected by the road traffic emissions from the existing road networks, portal, bus and minibus terminus, heavy goods vehicles and coach parking sites, marine traffic emissions and industrial emissions within the study area.

3.3.1.2 The nearest EPD air quality monitoring station is Tsuen Wan monitoring station. The annual average monitoring data recorded at EPD’s Tsuen Wan air quality monitoring station has shown general decreasing trend of pollutants’ concentration in the past five years. The recent five years (2018 – 2022) annual average concentrations of air pollutants relevant to the Project are summarized in Table 3.3.

Table 3.3 Average Concentrations of Pollutants in the Recent Five Years (Year 2018 – 2022) at Tsuen Wan EPD Air Quality Monitoring Station

Pollutant	Averaging Time		AQOs (µg/m^3)	2018	2019	2020	2021	2022
RSP	24-hr	10^th Highest	100	71	65	54	60	52
	Annual		50	30	30	24	24	22
FSP	24-hr	19^th Highest	50	41	40	32	34	32
	Annual		25	20	20	15	16	14
NO2	1-hr	19^th Highest	200	181	177	142	151	140
	Annual		40	45	46	36	44	39

Notes:

[1] Monitoring results exceeded AQOs are shown as bold and underlined characters.

[2] All data is calculated from the hourly data provided in EPD’s website (http://epic.epd.gov.hk/EPICDI/air/station/?lang=en)

[3] Reference conditions of gaseous pollutants concentration data: 293K and 101.325 kPa.

3.3.1.3 Apart from the air quality monitoring data, EPD has released a set of background levels from “Pollutants in the Atmosphere and their Transport over Hong Kong version 2.1” (PATH v2.1) model in July 2021. The PATH v2.1 model is a regional air quality model developed by EPD to simulate air quality over Hong Kong against the Pearl River Delta (PRD) as background. Year 2025 data of the assessment area extracted from PATH v2.1 is presented in Table 3.4. The predicted concentrations of NO₂, RSP and FSP at various averaging times would be lower than the AQOs.

Table 3.4 Background Air Pollutants in Year 2025 (Extracted from the PATH-v2.1)

Pollutant	Averaging Time		AQOs (µg/m^3)	Concentration in PATH v2.1 (Year 2025)
				(33,39)	(34,38)	(34,39)	(35,37)	(35,38)
RSP	24-hr	10^th Highest	100	60	62	62	63	62
	Annual		50	27	28	28	28	28
FSP	24-hr	19^th Highest	50	33	34	33	34	33
	Annual		25	15	15	15	15	15
NO2	1-hr	19^th Highest	200	128	147	134	147	143
	Annual		40	23	30	25	30	27

Notes:

[1] The annual RSP and FSP concentrations are adjusted by adding 10.3 µg/m³ and 3.5 µg/m³ respectively with reference to “Guidelines on Choice of Models and Model Parameters”.

[2] 10^th highest daily RSP concentration is adjusted by adding 11.0 µg/m³ respectively with reference to “Guidelines on Choice of Models and Model Parameters”.

3.4 Identification of Air Sensitive Receivers

3.4.1.1 In accordance with Annex 12 of the EIAO-TM, any domestic premises, hotel, hostel, hospital, clinic, nursery, temporary housing accommodation, school, educational institution, office, factory, shop, shopping centre, place of public worship, library, court of law, sports stadium or performing arts centre are considered as air sensitive receivers (ASRs). Any other premises or place with which, in terms of duration or number of people affected, has a similar sensitivity to the air pollutants as the aforelisted premises and places is also considered to be a sensitive receiver.

3.4.1.2 In accordance with the EIA Study Brief, the assessment area for air quality assessment should be defined by a distance of 500 m from the boundary of the Project site. Illustration of the proposed assessment area is presented in Figure 3.1.

3.4.1.3 For identification of the representative ASRs within the assessment area that would likely be affected by the potential impacts from the construction and operation of the Project, a review has been conducted based on relevant available information including topographic maps, Outline Zoning Plans (OZPs) and other published plans in the vicinity of the Project site. The representative ASRs within the assessment area are presented in Table 3.5 and illustrated in Figure 3.2a, Figure 3.2b, Figure 3.2c and Figure 3.2d.

Table 3.5 Representative Air Sensitive Receivers in the vicinity of the Project

ASR ID	Description	Land Use	Approx. Distance between ASR and the Nearest Road Alignment (m)	Assessment Height Above Ground (mAG) [1]
A1	Tsuen Wan West Sports Centre	Recreational	315	1.5 - 20
A2	Tsuen Wan Government Primary School	Educational	218	1.5 - 25
A3	Bayview Garden Phase 3 Block 5	Residential	139	12 - 130
A4	Belvedere Garden Phase 1 Tower 2	Residential	143	1.5 - 110
A5	Serenade Cove Block B	Residential	36	15 - 110
A6	Southeast Industrial Building	Industrial	42	9 - 100
A7	Tennis Court at the Panorama	Recreational	163	1.5
A8a	Kong Nam Industrial Building	Industrial	125	4 ^[2]- 95
A8b	Kong Nam Industrial Building	Industrial	40	16 ^[3] - 95
A9	Basketball Court at Hoi On Road Playground	Recreational	14	1.5
A10	Chai Wan Kok Cooked Food Market	Shop	51	1.5
A11	TML Tower	Industrial	65	1.5 - 150
A12	Metropolitan Factory and Warehouse Building	Industrial	63	5 - 50
A13	Million Fortune Industrial Centre	Industrial	67	9 - 95
A14	Tsuen Tung Factory Building	Industrial	67	4 - 90
A15	Cable TV Tower	Commercial	67	17 - 180
A16	One Midtown	Industrial	88	15 - 170
A17	Golden Bear Industrial Centre	Industrial	95	13 - 85
A18	Shield Industrial Centre	Industrial	99	8 - 120
A19	Summit Terrace Tower 2	Residential	246	15 - 150
A20	Tsuen Tak Gardens Block D	Residential	341	1.5 - 140
A21	The Octagon	Commercial	288	1.5 - 150
A22	International Trade Centre	Commercial	291	9 - 75
A23	Yue Fung Industrial Building	Industrial	163	1.5 - 70
A24	Wang Cheong Enterprise Centre	Commercial	200	1.5 - 85
A25	Chai Wan Kok Rest Garden	Recreation	122	1.5
A26	Po On Commercial Association Wong Siu Ching Secondary School	School	161	1.5 - 30
A27	Clague Garden Estate Block A	Residential	74	1.5 - 110
A28a	Salvation Army Ng Kok Wai Memorial Kindergarten	School	46	1.5 - 10
A28b	Salvation Army Ng Kok Wai Memorial Kindergarten	School	34	1.5 - 10
A29	Clague Garden Estate Block B	Residential	98	1.5 - 120
A30	Clague Garden Estate Block C	Residential	92	1.5 - 120
A31	Clague Garden Estate Basketball Court	Recreational	73	1.5
A32	Parc City Tower 5	Residential	78	1.5 - 150
A33	Parc City Tower 3	Residential	37	1.5 - 120
A34	Parc City Tower 2	Residential	30	1.5 - 85
A35	Parc City Tower 1	Residential	51	5 - 60
A36	Ocean Pride Tower 10	Residential	39	30 - 160
A37	Ocean Pride Tower 9	Residential	95	30 - 160
A38	Ocean Pride Tower 8	Residential	55	30 - 160
A39	Ocean Pride Tower 7	Residential	22	30 - 160
A40	TCL Tower	Industrial	480	1.5 - 60
A41	Fortune Building	Residential	367	1.5 - 20
A42	Sha Tsui Road Playground	Recreational	433	1.5
A43	Tsuen Wan Town Hall	Recreational	309	1.5 - 20
A44	Skyline Plaza (Residential)	Residential	151	1.5 - 130
A45	Peace House	Residential	370	1.5 - 30
A46	Vision City Tower 1 / Sage Tsuen Wan District Elderly Community Centre	Residential / G/IC	254	1.5 - 180
A47	Nina Tower	Commercial	145	1.5 - 320
A48	L'hotel Nina et Convention Centre	Hotel	163	8 - 170
A49	The Dynasty Tower 2	Residential	198	1.5 - 200
A50	99 Chung On Street	Residential	372	1.5 - 20
A51	Asia Tone i-Centre	Commercial	477	1.5 - 40
A52	Kwong Fat Building	Residential	555	1.5 - 35
A53	Tsuen Wan Park	Recreational	11	1.5
A54	Tsuen Wan Park Children Cycling	Recreational	18	1.5
A55^[4]	Planned Joint-user Complex at Texaco Road, Tsuen Wan	G/IC	56	1.5 - 30
A56	The Dynasty Tower 1	Residential	176	1.5 - 210
A57	Aurora Tower 1	Residential	133	1.5 - 95
A58	Gunzetal Ltd	Industrial	106	1.5 - 50
A59	Texaco Road Industrial Centre	Industrial	85	12 - 65
A60	Proposed Industrial Building	Industrial	58	1.5 - 95
A61	Harmony Garden Block 1	Residential	349	1.5 - 80
A62	Chelsea Court (Tower East)	Residential	226	28 - 180
A63	Houston Industrial Building	Industrial	108	1.5 - 80
A64	Tsuen Wan Industrial Centre	Industrial	14	10 - 95
A65	Metropolitan Factory and Warehouse Building No. 2	Industrial	20	5 - 80
A66a	Wofoo Building	Industrial	15	5 - 55
A66b	Wofoo Building	Industrial	47	5 - 55
A67	Lucida Industrial Building	Industrial	155	1.5 - 100
A68	Indi Home	Residential	258	1.5 - 200
A69	Edward Wong Industrial Centre	Industrial	416	5 - 40
A70	Goodman Tsuen Wan Centre	Commercial	92	18 - 140
A71a	Leader Industrial Centre	Industrial	45	1.5 - 70
A71b	Leader Industrial Centre	Industrial	36	1.5 - 70
A72	Lin Fung Centre	Industrial	39	7 - 55
A73	Sandoz Centre	Industrial	44	5 - 85
A74	Tak Fung Industrial Centre	Industrial	50	11 - 70
A75a	Kerry (Tsuen Wan) Warehouse	Industrial	36	6 - 110
A75b	Kerry (Tsuen Wan) Warehouse	Industrial	24	6 - 110
A76	Good Ba Ba Hitech Building	Industrial	99	5 - 45
A77	Planned Industrial and Data Centre	Industrial	18	1.5 - 210
A78	Wing Kei Road 5-A-Side Soccer Pitch	Recreational	24	1.5
A79	Sunley Centre	Industrial	36	8 - 75
A80	Riviera Gardens Block 10 Hoi Sing Mansion	Residential	46	1.5 - 120
A81	Riviera Gardens Block 5 Hoi Tao Mansion	Residential	167	1.5 - 120
A82	Riviera Gardens Block 12 Hoi Fung Mansion	Residential	25	1.5 - 120
A83	HKBU Tsuen Wan Campus	School	37	1.5 - 15
A84	Riviera Gardens Block 18 Hoi Fai Mansion	Residential	81	1.5 - 110
A85	Riviera Gardens Block 20 Hoi Kwai Mansion	Residential	30	1.5 - 110
A86	Riviera Gardens Block 21 Hoi Yin Mansion	Residential	44	1.5 - 110
A87	Riviera Gardens Block 22 Hoi Yue Mansion	Residential	71	1.5 - 110
A88	Proposed School Site at TW7	School	77	1.5 - 20
A89a	City Point Block 8	Residential	45	22 - 140
A89b	City Point Block 8	Residential	31	22 - 140
A90	City Point Block 7	Residential	27	22 - 140
A91	City Point Block 6	Residential	19	22 - 150
A92	Riviera Gardens Block 1 Hoi Po Mansion	Residential	155	5 - 90
A93	City Point Block 5	Residential	18	22 - 150
A94	Shak Chung Shan Memorial Catholic Primary School	School	147	1.5 - 25
A95	City Point Block 3	Residential	23	22 - 150
A96	City Point Block 2	Residential	21	22 - 150
A97	City Point Block 1	Residential	18	22 - 150
A98	The Pavilia Bay Tower 2	Residential	86	22 - 170
A99	Tsuen Wan Sports Centre	Recreational	37	1.5 - 30
A100	The Pavilia Bay Tower 1	Residential	79	22 - 180
A101	Allied Cargo Centre	Industrial	83	15 - 130
A102	Lung Shing Factory Building	Industrial	121	5 - 85
A103	Goodman Texaco Centre	Industrial	191	7 - 80
A104	EW International Tower	Industrial	241	6 - 110
A105	Goodman Texaco Centre	Industrial	291	27 - 150
A106	Tung Cheong Industrial Building	Industrial	337	5 - 35
A107	100 Texaco Road	Industrial	375	5 - 35
A108	Sheung Chui Court Chui Ting House	Residential	460	1.5 - 120
A109	Po Yip Building	Industrial	558	5 - 70
A110	Tai Wo Hau Estate Fu Yin House	Residential	492	1.5 - 110
A111	Tower 1 High Prosperity Terrace	Residential	421	1.5 - 120
A112	Kerry Cargo Centre	Industrial	227	23 - 130
A113	Shun Hing Centre	Commercial	83	5 - 120
A114	Chun Shing Factory Estate	Industrial	20	8 - 90
A115	Citic Telecom Tower	Commercial	8	5 - 120
A116	Sir Robert Black College of Education Past Students' Association Lu Kwong Fai Memorial School	Educational	422	1.5 - 30
A117	Kwai Shing West Estate Block 5	Residential	334	1.5 - 70
A118	Kwai Shing West Estate Block 6	Residential	184	1.5 - 60
A119	SKH Chu Yan Primary School	School	148	1.5 - 30
A120	Kwai Shing West Estate Block 8	Residential	133	1.5 - 70
A121	Horizon Place Tower One	Residential	394	21 - 120
A122	Lions College	Educational	368	1.5 - 25
A123	Lok Sin Tong Ku Chiu Man Secondary School	Educational	346	1.5 - 25
A124	Kwai Shing West Estate Block 9	Residential	179	1.5 - 60
A125	CNEC Lee I Yao Memorial Secondary School	School	76	1.5 - 30
A126	Gold Way Industrial Centre	Industrial	9	1.5 - 65
A127	Planned Industrial Building	Industrial	10	10 - 100
A128	Wing Shing Industrial Building	Industrial	11	5 - 40
A129	Kwai Shing Swimming Pool	Recreational	184	1.5
A130	Metro Loft	Commercial	57	16 - 100
A131	Kingsford Industrial Building Phase I	Industrial	62	5 - 95
A132	Kai Bo Group Centre	Industrial	65	15 - 65
A133	Waford Industrial Building	Industrial	65	6 - 45
A134	Brilliant Cold Storage Tower	Industrial	65	6 - 85
A135	Yee Lim Industrial Centre Block B	Industrial	142	5 - 60
A136	Kwai Chung Sports Ground	Recreational	197	1.5
A137	Wing Hang Industrial Building	Industrial	57	12 - 60
A138	Wah Fung Industrial Centre	Industrial	82	9 - 70
A139a	Marvel Industrial Building Block B	Industrial	12	5 - 65
A139b	Marvel Industrial Building Block B	Industrial	28	5 - 65
A140	Wing Hong Industrial Building	Industrial	67	1.5 - 60
A141	Profit Industrial Building	Industrial	11	10 - 65
A142	Fook Yip Building	Industrial	162	1.5 - 100
A143	New Kwai Fong Garden Block A	Residential	316	15 - 110
A144	Ha Kwai Chung Polyclinic & Special Education Centre	Clinic	300	1.5 - 30
A145	Lai King Estate Ming King House	Residential	366	1.5 - 45
A146	Lai King Estate Fung King House	Residential	210	1.5 - 45
A147	Lai King Catholic Secondary School	School	186	1.5 - 25
A148	CEDD Public Works Regional Laboratory (Tsuen Wan)	Industrial	96	1.5 - 5
A149	Cargo Consolidation Complex	Industrial	185	20 - 90
A150	Ever Gain Plaza	Commercial	31	45 - 130
A154	Kwai Shun Street Playground	Recreational	4	1.5
A155	Kwai Shun Industrial Centre	Industrial	38	5 - 45
A156	Golden Industrial Building	Industrial	50	1.5 - 55
A157	Kwai Tak Industrial Building Block 2	Industrial	38	7 - 45
A158	Kwai Chung Park	Recreational	61	1.5
A159	Hopewell Logistics Centre	Industrial	141	5 - 45
A160	Kwai Wan Industrial Building	Industrial	8	5 - 80
A161	Wing Kin Industrial Building	Industrial	9	11 - 85
A162	Shui Hing Tannery Factory Ltd	Industrial	9	1.5 - 10
A163	Kai Bo Food Tower	Industrial	79	5 - 45

Notes:

[1]: The lower bound of assessment height shown in the table is the lowest level with air-sensitive uses.

[2]: No air-sensitive uses below 4mAG were identified for the façade of A8a facing Castle Peak Road - Tsuen Wan Road.

[3]: No air-sensitive uses below 8mAG were identified for the façade of A8b facing Hoi On Road.

[4]: The planned Joint-user Complex at Texaco Road, Tsuen Wan (A55) is still in preliminary design stage and no layout is available. According to OZP, the G/IC building is limited to 4 storeys. Therefore, the assessment height is taken as 1.5 - 30 mAG.

[5]: The Kwai Shun Street Cooked Food Market will be relocated and will not be considered as ASR.

3.5 Identification of Environmental Impacts

3.5.1 Construction Phase

3.5.1.1 During the construction phase, the Project would generate fugitive dust with potential impacts on neighbouring ASRs from various construction activities, including site clearance, demolition of the existing structure, and minor excavation with limited backfilling for column installation and wind erosion of the limited exposed area. Due to site constraint, the abovementioned construction works would be small-scale and confined within a small work area. Work area with dusty activities such as minor excavation with limited backfilling for each column installation would be approximately 250m² as confirmed by Project Engineer. The shortest separation distance between the dusty activities (i.e., column installation) and ASR (i.e., A64 - Tsuen Wan Industrial Centre) is approximately 17m. Considering the dusty activities would be short-term and localized with the implementation of dust suppression measures, the impact of the dusty activities to the nearest ASR is considered as limited.

3.5.1.2 It is understood that construction activities would not take place concurrently at the entire construction work area, but to be undertaken at multiple work fronts at different construction periods. For retaining structures for at-grade work and slopework in Works Area 3 (between Tsuen Tsing Interchange and Kwai Tsing Interchange section) and Works Area 4 (between Kwai Tsing Interchange and Container Port Road Section) presented in Figure 3.3a and Figure 3.3b, each activity location shall occupy about 100m in length of the Project alignment at any one time with a separation distance separation more than 300m between each location. Given an average dump truck capacity of 7.5m³, it is estimated that a maximum of 10 trips of dump trucks from all work activities will be required to dispose of the C&D material each day, and thus the maximum amount of handling C&D material for the project per day is about 75m³, which is a relatively small amount of excavated materials. In addition, the dump trucks would be covered by clean impervious sheeting to minimise dust nuisance to the nearby ASRs. Given that work area with dusty activity and the number of handled materials is small, dust impacts during the construction phases are anticipated to be insignificant with the implementation of mitigation measures stipulated in the Air Pollution Control (Construction Dust) Regulation.

3.5.1.3 Fuel combustion from the use of powered mechanical equipment (PME) during construction works could be a source of PM, NO₂, SO₂ and CO. Due to the small scale of the works area, only a small number of PMEs (less than 23 PMEs which in operation at the same time) will be required on-site under normal operation. Limited smoke and gaseous emissions would be generated from such equipment with proper maintenance. According to the Air Pollution Control (Non- Road Mobile Machinery (NRMM)) (Emission) Regulation, only approved or exempted NRMMs with a proper label are allowed to be used in specified activities and locations including construction sites. In addition, Air Pollution Control (Fuel Restriction) Regulation is imposed on the types of fuels allowed for use and their sulphur contents in commercial and industrial processes. Considering the limited number of equipment to be used on the site and the use of equipment in compliance with the Air Pollutant Control (Non-Road Mobile Machinery (NRMM)) (Emission) and Air Pollution Control (Fuel Restriction) Regulations, the emission from construction equipment is considered relatively small and would not cause adverse air quality impact to the surrounding ASRs.

3.5.1.4 Land-based sediment is anticipated at the northern and southern portion of the proposed widened TWR alignment (the locations are illustrated in Figure 6.1, Figure 6.2, Figure 6.3 and Figure 6.4). However, no odour emissions were detected during the ground investigation. Under the Project, there would be the construction of new bridge piers for the modification of the existing TWR viaduct and new supporting columns for proposed noise enclosures using the bored pile method in these areas. Thus, it is inevitable that land-based sediment will be involved during the piled foundation construction. The quantities of land-based sediment to be excavated are expected to be approximately 2,100m³. However, if any odour arising from the land-based sediment is detected, the recommended mitigation measures listed in Section 3.8.1 will be implemented. Given the limited land-based sediment to be excavated and with the implementation of good site practice recommended in Section 3.8.1, odour nuisance is expected to be minimal.

3.5.1.5 Referring to Section 8.4.3.2, there is a possibility of encountering waste pockets during excavation at the slope near Tsuen Wan Road within Gin Drinkers Bay Landfill (as shown in Figure 8.1). However, it is important to note that since the closure of Gin Drinkers Bay Landfill in 1979, the landfill has fully stabilized. As a result, it is expected that odour emissions arising from these waste pockets during the excavation will be minimal. If any odour is detected, the recommended mitigation measures listed in Section 3.8.1 will be implemented. By following the good site practices outlined in Section 3.8.1, odour nuisance is expected to be minimal.

3.5.2 Operation Phase

3.5.2.1 Potential air quality impacts during the operation phase of the Project would be associated with the following pollution sources. Figure 3.4 shows industrial emission sources, major emission sources within 4 km and marine emission source while Figure 3.5 presents the portal emissions.

Within the 500m study area

· Background pollutant concentrations;

· Industrial emissions within 500m study area of the Project Site boundary (locations shown in Figure 3.4);

· Vehicular emission from open sections of existing, and proposed roads within 500m study area and the associated PATH grids (i.e., 1km × 1km) from the project boundary;

· Vehicular emission associated with the existing bus and minibus termini in public transport interchange (PTI), on-street minibus termini, heavy goods vehicle, and coach parking site;

· Portal emissions from the existing underpasses at Castle Peak Road – Tsuen Wan and Cheung Pei Shan Road, the existing noise enclosures at Tsuen King Circuit (locations shown in Figure 3.5) and the proposed full enclosure along Tsuen Wan Road (locations shown in Figure 3.6a and Figure 3.6b); and

· Marine emissions from ferry travelling from Tsuen Wan Ferry Pier to Park Island and other vessels accessing to Rambler Channel (locations shown in Figure 3.4).

Other Major Point Sources within 4 km

· Industrial emission from Chemical Waste Treatment Facilities (CWTC) (locations shown in Figure 3.4);

· Industrial emission from Tsing Yi Asphalt Plant (locations shown in Figure 3.4); and

· Industrial emission from Kwai Chung Crematorium (locations shown in Figure 3.4).

Identification of Key Air Pollutants of Vehicular emissions from Open Road

3.5.2.2 The Project induces vehicular emission from the open sections of the proposed road networks. Vehicular emission comprises a number of pollutants, including NO_x, RSP, FSP, etc. According to “An Overview on Air Quality and Air Pollution Control in Hong Kong” published by EPD, motor vehicles are the main causes of high concentrations of RSP, FSP and NO_x at street level in Hong Kong and are considered as key air quality pollutants for road projects. For other pollutants, due to the low concentration in vehicular emission, they are not considered as key pollutants for the purpose of this study.

(i) Nitrogen Dioxide (NO₂)

3.5.2.3 Nitrogen oxides (NO_x) is a major pollutant from fossil fuel combustion. According to the 2020 Hong Kong Air Pollutant Emission Inventory Report published by EPD, navigation was the dominant contributor to NO_x generation in Hong Kong, accounting for 36% of NOx emission in 2020. Road transport was also a major NOx contributor which accounted for 19% of the total in the same year.

3.5.2.4 In the presence of O₃ and VOC, NO_x would be converted to NO₂. The proposed road networks would inevitably influence the distribution of NOx emission and subsequently the roadside NO₂ concentration. Hence, NO₂ is one of the key pollutants for the operational air quality assessment of the Project. 1-hour and annual averaged NO₂ concentrations at each identified ASRs would be assessed and compared with the relevant AQO to determine the compliance.

(ii) Respirable Suspended Particulates (RSP)

3.5.2.5 Respirable Suspended Particulates (RSP) refers to suspended particulates with a nominal aerodynamic diameter of 10µm or less. According to the 2020 Hong Kong Air Pollutant Emission Inventory Report published by EPD, navigation is the dominant contributor to RSP generation in Hong Kong, accounting for 29% of RSP emission in 2020. Road transport is also a RSP contributor which accounted for 10% of the total in the same year. The proposed road networks would inevitably influence the distribution of RSP emission and subsequently the roadside RSP concentration. Hence, RSP is also one of the key pollutants for the operational air quality assessment of the Project. 24-hour and annual averaged RSP concentrations at each identified ASRs would be assessed and compared with the relevant AQO to determine the compliance.

(iii) Fine Suspended Particulates (FSP)

3.5.2.6 Fine Suspended Particulates (FSP) refers to suspended particulates with a nominal aerodynamic diameter of 2.5µm or less. According to the 2020 Hong Kong Air Pollutant Emission Inventory Report published by EPD, navigation is the dominant contributor to FSP generation in Hong Kong, accounting for 35% of FSP emission in 2020. Road transport is also a FSP contributor which accounted for 11% of the total in the same year. The proposed road networks would inevitably influence the distribution of FSP emission and subsequently the roadside FSP concentration. Hence, FSP is also one of the key pollutants for the operational air quality assessment of the Project. 24-hour and annual averaged FSP concentrations at each identified ASRs would be assessed and compared with the relevant AQO to determine the compliance.

3.5.3 Concurrent Projects

3.5.3.1 As stated in Section 2.8, there are several concurrent projects identified within 500m of the Project. The construction works of the Project will be tentatively commenced in 2028 and be completed in 2033 without Slip Road C and in 2036 with Slip Road C. All planned and committed concurrent projects are summarized as follows:

· Improvement Works at Tsuen Tsing Interchange, by Highways Department (HyD);

· Proposed Columbarium Building at Site No. 10 Tsing Tsuen Road, by the Board of Management of the Chinese Permanent Cemeteries (BMCPC);

· Flyover from Kwai Tsing Interchange Upramp to Kwai Chung Road, by Highways Department (HyD); and

· Improvement Works at Tai Chung Road Interchange, by Highways and Department (HyD);

3.5.3.2 Based on the available information shown in Table 2.3, the construction of Improvement Works at Tsuen Tsing Interchange (IWTTI project) is anticipated to commence in 2023 for completion in 2026. Therefore, no cumulative construction dust impact is expected during the construction phase. The cumulative impact during the operation phase of the Project in association with the IWTTI project has been considered.

3.5.3.3 Improvement Works at Tai Chung Road Interchange (IWTCRI project) is a modification to the existing Tai Chung Road Interchange (TCRI). IWTCRI project mainly comprises provision of exclusive left-turn lane from Hoi Hing Road to TWR (Tuen Mun bound); provision of free-flow left-turn lane from Tai Chung Road to TWR (Kowloon bound); and refinement of TCRI roundabout and associated arms refinement road side works. The construction of the IWTCRI project is anticipated to commence in 2028 and complete in 2030. Upon completion of the IWTCRI project, the current congested traffic condition at TCRI will be alleviated. With reference to the construction programme of the Project, the construction of Slip Road E would be carried out from 2030 to 2033. Therefore, the construction works of IWTCRI project and Slip Road E would not be conducted concurrently while the construction works of other parts of the Project will be carried out with separation distance of more than 300m. Hence, the cumulative adverse impact arising from this concurrent project is insignificant. Furthermore, as the forecast traffic flow data adopted for the air quality impact assessment in the Project already included the effect of the completion of IWTCRI project, the cumulative impact during the operation phase of the Project in association with the IWTCRI project has been considered.

3.5.3.4 The construction works of the Flyover from Kwai Tsing Interchange (KTI) Upramp to Kwai Chung Road (KCR) commenced in 2021 and will be completed in 2025. Therefore, no cumulative construction dust impact is expected during the construction phase. Furthermore, as the forecast traffic flow data adopted for the air quality impact assessment in the Project already included the effect of the completion of Flyover from KTI Upramp to KCR, the cumulative impact during the operation phase of the Project in association with this project has been considered.

3.5.3.5 A 4-floor columbarium building will be constructed at Tsing Tsuen Road (hereinafter referred to as “the planned columbarium”) which is anticipated to commence in Q2 2024 and complete in Q2 2030. Although there is no overlap of works area between the proposed columbarium building project and this Project, the proposed columbarium building project falls inside the Study Area of the Project. The overlapping of construction period between the two projects will be from 2028 (tentative commencement year of the Project) to 2030 (tentative completion year of proposed columbarium building project). In view that the most dusty construction works of the proposed columbarium building project would be the site formation and foundation works for the building which are anticipated to be substantially completed by the time when the construction for the Project commence in 2028, the tentative construction programme and works between the two projects could be arranged efficiently through close liaison between HyD’s and the Board of Management of the Chinese Permanent Cemeteries (BMCPC)’s contractors to avoid construction works of respective works contracts to be carried out concurrently at the close proximity areas. Given the nature of the proposed columbarium building, no cumulative environmental impact is anticipated during operation phases of the Project in association with the columbarium building project.

3.6 Assessment Methodology

3.6.1 Construction Phase

3.6.1.1 Considering the small scale and nature of the construction activities for the Project, the potential fugitive dust nuisance during the construction phase should be limited with the implementation of mitigation measures stipulated in Air Pollution Control (Construction Dust) Regulation and good site practices recommended in Section 3.8.1. Therefore, adverse construction dust impact to surrounding ASRs is not anticipated and a quantitative construction dust assessment is not necessary.

3.6.2 Operation Phase

3.6.2.1 PATH v2.1, CALINE4 and AERMOD models are used to simulate the dispersion of emission from the sources identified in Section 3.5.2.1. The future background concentrations for air pollutants from the PATH v2.1 model are adopted. CALINE4 model is used to simulate line sources including open road emissions within the study area. AERMOD model is used to simulate portal emission (volume source), vehicular emission associated with the existing bus and minibus termini in Public Transport Interchange (PTI), on-street minibus termini, heavy goods vehicle and coach parking site (area, areapoly and volume sources), marine emissions (volume, horizontal point and point sources) and industrial emission (point source) within the study area.

Vehicular Emissions from Open Roads

3.6.2.2 Open sections of existing and planned road networks within 500 m of the boundary of the Project site were considered in this study. The predicted 24-hour traffic flow and vehicle compositions at the identified roads during operation phase provided by the traffic consultant were adopted to assess the potential air quality impact from the open roads. The traffic data adopted for the assessment is presented in Appendix 3.1. Transport Department has no comment on the use of the traffic forecast for this Project and the endorsement letter is attached in Appendix 3.1.

3.6.2.3 EMFAC-HK v4.3 model was adopted to estimate the vehicular emission rates of NOx (i.e., initial NO + initial NO₂), RSP and FSP for vehicular emission arising from open road, portal, existing bus termini, minibus termini in PTI, on-street PLB and heavy goods vehicles and coach parking site within 500m study area. The “vehicle fleet” refers to all motor vehicles operating on roads within this assessment area. The modelled fleet is broken down into 18 vehicle classes based on the vehicle population provided by EPD. The detailed input parameters and model assumptions made in EMFAC-HK model are summarized in Appendix 3.2.

3.6.2.4 The vehicular emission burdens of NOx and RSP from commissioning year to 15 years after commissioning, namely Years 2033, 2036, 2042 and 2048, were estimated with EMFAC-HK model and are shown in Appendix 3.2. The vehicular emission attained the highest in Year 2033. Year 2033 was therefore selected as the representative assessment year.

3.6.2.5 Given the commissioning year of the proposed Slip Road C in the Year 2036, subject to its implementation ascertained in the further traffic review as presented in Section 2.5.5, the vehicular emission was calculated using the traffic forecast data of Slip Road C in Year 2036 combined with the Exhaust Technology Fraction in the Year 2033. Therefore, the vehicular emission from Slip Road C has been included in the Year 2033 as a conservative approach.

3.6.2.6 The resulting hourly emissions of NO, NO₂, RSP and FSP were divided by the number of vehicles and the distance travelled to obtain the emission factors in gram per miles per vehicle. The calculated 24-hour initial NO, NO₂, RSP and FSP emission factors of 18 vehicle classes for each road type under each scenario were adopted in the subsequent air dispersion modelling, and are presented in Appendix 3.3. The 24-hour traffic flows and composite emission factors for each road link are presented in Appendix 3.4.

3.6.2.7 Referring to Section 4.9.2.4, direct noise remedies such as noise barriers, semi-enclosures and full enclosures are proposed under this Project. Secondary air quality impacts arising from the implementation of the existing and proposed roadside noise mitigation measures, such as vertical noise barriers, vertical noise barriers with canopies, semi-enclosure and full enclosure, were incorporated into the air quality model. The proposed noise mitigation measures are presented in Figure 3.6a and Figure 3.6b.

3.6.2.8 It is assumed that, with the installation of vertical noise barriers, all traffic pollutants generated from the mitigated road section are emitted from the top of the noise barriers. In the CALINE4 model, the elevation of the mitigated road section was set to the elevation of the barrier top. No correction or adjustment to the receiver heights was made in the model.

3.6.2.9 For vertical noise barriers with canopies and semi-enclosure, it is assumed that dispersion of traffic pollutants is in effect similar to physically shifting the mitigated road section towards the central divider. The traffic pollutants are assumed to emit from the top of the canopies. In the CALINE4 model, the alignment of the mitigated road section was shifted by a distance equal to the covered extent. The elevation of the mitigated road section was set to the elevation of the barrier top. No correction or adjustment to the receiver heights was made in the model.

Portal Emissions from the underpass at Castle Peak Road – Tsuen Wan and Cheung Pei Shan Road (near D. Park Shopping Centre), Noise Enclosure at Tsuen King Circuit and the Proposed Noise Enclosure at Tsuen Wan Road

3.6.2.10 The portal emissions (initial NO, initial NO₂, RSP and FSP) of the underpasses at Castle Peak Road -Tsuen Wan, Cheung Pei Shan Road (near the D. Park Shopping Centre), noise enclosure at Tsuen King Circuit and the proposed noise enclosure at Tsuen Wan Road are calculated based on the 24-hour vehicle emission factors predicted by EMFAC-HK model and vehicle flows provided by the traffic consultant. The locations of portal emissions are presented in Figure 3.5 and the detailed calculation of the portal emissions are represented in Appendix 3.5.

3.6.2.11 Portal emissions were modelled in accordance with the Permanent International Association of Road Congress Report (PIARC, 1991). Pollutants were assumed to eject from the portal as a portal jet such that 2/3 of the total emissions were dispersed within the first 50 m of the portal and 1/3 of the total emissions within the second 50 m.

Vehicular Emission Associated with the Existing Bus Termini and Minibus Termini in PTI, On-street Minibus Termini, Heavy Goods Vehicle and Coach Parking Site

3.6.2.12 Despite the inclusion of start emissions on local/rural roads for most of the vehicle classes except franchised buses, public light buses, heavy goods vehicles and coach, start emissions induced by the identified bus and minibus termini, heavy goods vehicle and coach parking sites were further simulated to avoid any underestimation of air quality impact at the exit of the termini and parking sites. The start emissions, running exhaust emissions and idling emission associated with the vehicles at the existing bus and minibus termini, heavy goods vehicle and coach parking sites within the assessment area were calculated based on the start emission and running exhaust emission factors predicted by EMFAC-HK model, cold idling emission factors from the Calculation of Start Emissions in Air Quality Impact Assessment published by EPD, warm idling emission factors from Road Tunnels: Vehicle Emissions and Air Demand for Ventilation published by World Road Association and traffic data provided by the traffic consultant.

3.6.2.13 Calculations of emission associated with the bus and minibus termini, heavy goods vehicle and coach parking sites were referenced to the Calculation of Start Emission in Air Quality Impact Assessment published by EPD. Start emissions for diesel vehicles fitted with selective catalytic reduction (SCR) devices vehicles were adjusted based on the idling emission and would be released over total spread distance of 700 m from where the start takes place, start emissions for liquefied petroleum gas (LPG) minibus were adjusted based on the idling emission and would be released over a total spread distance of 150 m from where the start takes place, while running exhaust and idling emissions would be released on the spot. For identified terminus and parking sites, running exhaust and idling emissions from terminating and non-terminating vehicles, and adjusted start emission from terminating vehicles are considered for emissions inside terminus/ parking sites while the remaining adjusted start emission from terminating vehicles is considered for emissions outside terminus/parking sites. The locations of emission sources associated with the existing bus termini and minibus termini in PTI, heavy goods vehicles and coach parking sites of which the start emissions are estimated by the precise approach and the detailed calculation of the emissions are presented in Appendix 3.6. A total of 4 PTIs (i.e., PT2 – Tsuen Wan West Station PTI, PT5 – Nina Tower Bus Terminus PTI, PT8 – Bayview Garden Bus Terminus, and PT11- Kwai Tsui Estate Bus Terminus) have been installed with mechanical ventilation systems for exhaust. To avoid any underestimating the emission from these PTIs, additional emission sources are assigned to the openings, ingress and egress.

3.6.2.14 Several sensitivity tests were conducted between the broad-brush approach and the precise approach of the existing HGV carpark,1 PC car park in very close proximity, and on-street minibus termini. For the existing HGV carpark, the broad-brush approach provides generally more conservative results for HGV parking spaces less than or equal to 100 while the precise approach is more appropriate to be adopted for carpark with HGV parking spaces more than 100. The HGV traffic flow on the nearby roads is greater than that within the carpark with less than 100 parking spaces, so the total emission burden from the nearby road is much greater than that within the HGV carpark. As such, the broad-brush approach provides a more conservative result at the ASRs with HGV parking spaces less than or equal to 100. For private car carpark, it is noted that the start emission factor of private car is much lower than those of HGV, FBSD and FBDD. Broad-brush approach was considered reasonable and adopted for start emissions at private car carparks. Nevertheless, considering the close proximity of the Tsuen Wan Plaza Carpark to the surrounding ASRs (the shortest separation distance between the ventilation exhaust outlet and the ASRs is approximately 17m), a precise approach was specifically used for a more realistic start emission estimation at this carpark.

3.6.2.15 The sensitivity test was also performed on start emissions at on-street minibus termini. Based on the on-site observation, the start emissions at on-street minibus termini only took place within an hour. As such, start emissions emitted from these on-street minibus termini would be concentrated within this hour and those emissions during the remaining hours were insignificant. The predicted maximum hourly and the annual NOx concentrations at the selected ASRs near to Kwai Shing (Kwai Hau Street) minibus terminus (PLB12) estimated by the precise approach and the hybrid approach (i.e., start emissions within the on-street minibus terminus are modelled as an “AREAPOLY” source while the start emissions from roads adjacent to the terminus are estimated by the broad-brush approach) were compared. The sensitivity test showed that the maximum hourly and annual NOx concentrations calculated by the hybrid approach for the selected ASRs are greater than those concentrations estimated by the precise approach. As such, the hybrid approach is adopted for the start emission at on-street minibus termini.

Marine Emissions

3.6.2.16 Tsuen Wan Ferry Pier and a small portion of Rambler Channel fall within the assessment area, emissions from the ferry service and vessels accessing Rambler Channel are considered in the assessment and the locations of the emission sources are presented in Figure 3.4 and the detailed assumptions are presented in Appendix 3.7.

3.6.2.17 As reviewed from the arrival and departure schedules on Park Island Transport Company Ltd.’s website, there would be a maximum of 3 regular ferry services daily from 10:35 to 16:35 using Tsuen Wan Ferry Pier. Emissions from the ferries during maneuvering and hoteling were calculated in the assessment. Existing marine traffic flows accessing Rambler Channel were based on the vessel count survey. Referring to the "Study on the Strategic Development Plan for Hong Kong Port 2030"[1], it is predicted that the throughput of the non-contained cargo will decline slightly during 2015 - 2030. The findings indicate that the number of River Trade Vessel (RTV) activities is not expected to increase from 2033 to 2048. Based on this best available information, a no-growth trend is assumed for the River Trade Vessel activities during the period of 2033 - 2048 for emission estimations.

3.6.2.18 With reference to the Study on Marine Vessels Emission Inventory (MVEIS) by HKUST, the marine emission is estimated in activities-based approach. The emission factors were derived in units of work (gram per kilowatt-hour), dependent on fractional load of the equipment during different vessel activity modes. The calculation can be summarized as below:

Emission = P × FL × T × EF

Where P is the installed power of equipment;

FL is fractional load of equipment in a specific mode;

T is operation time-in-mode; and

EF is fractional load emission factor of equipment.

3.6.2.19 Typical power equipment installed on marine vessels are Main Engine (ME) for propulsion, Auxiliary Engine (AE) for electricity and Auxiliary Boiler (AB) for fuel pre-heating and pumping. Subject to the vessel types, different combinations of engines are equipped on a vessel. Typical engine power rating engine type, fuel type of each vessel type was adopted from MVEIS.

3.6.2.20 Typical engine load factor by vessel type and by operation mode refers to MVEIS. The engine load factor is estimated by the Propeller Law and is defined as the ratio of actual speed over maximum speed of the vessel (MVEIS Section 3.2.10). The time-in-mode was estimated by the distance and vessel speed travelled in the corresponding mode (i.e., Fairway Cruise – over 12 knots; Slow Cruise – 8 to 12 knots; Maneuvering – 1 to 8 knots and Hoteling – below 1 knot). The hoteling time of the approaching vessel was assumed to be 5 mins at the ferry pier and landing step for the assessment purpose.

3.6.2.21 Stack height, diameter, exit temperature, and exit velocity are made reference to the stack parameters for all vessels in the approved EIA Lei Yue Mun Waterfront Enhancement Project (AEIAR-219/2018). The vessels were modelled as volume and point sources with horizontal release in AERMOD. The detailed calculation of the marine emissions is presented in Appendix 3.7.

Existing Industrial/Chimney Emission/ Other Major Sources within 4km

3.6.2.22 Based on chimney survey conducted on 7 July 2023, there are totally 20 chimney emission sources identified within the 500m study area. The chimney locations are presented in Figure 3.4 and Appendix 3.8.

3.6.2.23 The chimney parameters such as stack height, stack temperature, stack exit velocity, stack diameter and the locations for the chimneys are provided by either the management offices / tenant’s response or taken from the approved EIA Report of Tsuen Wan Bypass, Widening of Tsuen Wan Road between Tsuen Tsing Interchange and Kwai Tsing Interchanges and Associated Junction Improvement Works (AEIAR-124/2008).

3.6.2.24 Other major sources within 4km area from the Project boundary such as Chemical Waste Treatment Facility (CWTC) and Tsing Yi Asphalt Plant (AP-5) have been identified. The parameters and emission data of these emission sources are extracted from the SP licenses to develop the emission inventory. The detailed calculations of the industrial, chimney emission and other major sources within 4km are presented in Appendix 3.8.

Background Contributions

3.6.2.25 As suggested by “Guidelines on Assessing the ‘TOTAL’ Air Quality Impacts”, an integrated modelling system, PATH v2.1 which is developed and maintained by EPD is applied to estimate the background pollutant concentrations. The emission sources including those in Pearl River Delta Economic Zone, roads, marine, airport, power plants and industries within Hong Kong are all considered in the PATH v2.1 model.

3.6.2.26 The study area covers 5 grid cells of PATH v2.1, namely grid (33,39), (34,39), (34,38), (35,38) and (35,37). To avoid the double-counting of emissions from the vehicle within the study area, vehicular emission including NO₂, NO, FSP and RSP in the PATH v2.1 model for the abovementioned grid cells are deducted.

3.6.2.27 Although PATH v2.1 in Year 2030 is close to the operation year of the Project, as a conservative approach, the background pollutant concentrations in PATH v2.1 in Year 2025 are adopted. Given the proposed works will be completed and start operation in Year 2033, the vehicular emission for the remaining grids is projected to Year 2033 to avoid over-estimation of background pollutant concentrations for the cumulative air quality impact assessment.

3.6.2.28 According to the statistic presented in “The Clean Air Plan for Hong Kong 2035”, emissions from the power plant and vessels have been on a downward trend over the past decade. Under the implementation of control measures such as the elimination of coal-fired power generation and the tightening of emission cap, fuel standards, and using cleaner fuels for ocean-going vessels, emissions from power plants and vessels are to be reduced in the future. Emissions from vessels and power plants are expected to be lower in Year 2033 than that in Year 2025. As a conservative approach, emissions from the power plant and marine in the Year 2025 are adopted as the input for PATH emission inventory. The methodology for emission adjustment for PATH model is presented in Appendix 3.9.

Determination of the Assessment Scenarios

3.6.2.29 In order to evaluate the change in air quality impacts arising from the proposed road works as well as the proposed Direct Noise Remedies (DNR), three scenarios as described below have been assessed at the representative ASRs.

· Without Project Scenario – Scenario without the proposed road works.

· With Project (Without DNR) Scenario - Scenario with the proposed road works and without implementation of the proposed direct technical noise remedies; and

· With Project (With DNR) Scenario - Scenario with the proposed road works and with implementation of the proposed direct technical noise remedies.

Dispersion Modelling & Modelling Approach

Vehicular emissions from Open Roads

3.6.2.30 Traffic on all major existing and planned roads within the study area were included in this assessment. CALINE4 dispersion model, approved by the United States Environmental Protection Agency (USEPA), is used for the calculation of the NO, NO₂, RSP and FSP concentrations. Open sections of existing and planned road networks within the study area were considered in the model. The weighted surface roughness coefficient grid was taken for each grid in the CALINE4 model based on the land use characteristics of each grid. The weighted surface roughness coefficient and the proportions of land use for each grid are shown in Table 3.6.

Table 3.6 Summary of Surface Roughness Adopted in CALINE4 Model

Grid	Percentage of Urban Area (%)	Percentage of Grassland Area (%)	Percentage of Water Area (%)	Weighted Average Surface Roughness (cm)
33,39	55.0	17.3	27.6	212
34,38	62.5	10.9	26.6	237
34,39	100	0	0	370
35,37	83.8	16.2	0	318
35,38	100	0	0	370
Notes: [1] With reference to “Guidelines on Choice of Models and Model Parameters” by EPD, typical values of surface roughness (cm) 370 cm, 50 cm and 0.01 cm are assumed for the urban area, grassland area and water area, respectively. The weighted average surface roughness at the specific grid can be calculated as: Pwater × 0.01 + Purban × 370+ Pgrassland × 50. Where Pwater is the percentage of water area, Purban is the percentage of Urban area and Pgrassland is the percentage of Grassland Area. [2] The percentage of urban, grassland and water areas are calculated based on the PATH v2.1 grid size (i.e.,1km × 1km = 1km^2).

3.6.2.31 Under the current EPD guideline, the hourly meteorological data including wind speed, wind direction, and air temperature from the relevant grids from the WRF Meteorological data (same basis for PATH v2.1 model), were employed for the model run. The minimum wind speed was capped at 1 meter per second. The mixing height was capped between 131 meters and 1941 meters according to the observation in Year 2015 by Hong Kong Observatory (HKO). PCRAMMET was applied to generate Pasquill-Gifford stability class for the meteorological input to CALINE4 model based on the WRF meteorological data.

Vehicular Emissions from the Existing Bus Termini and Minibus Termini in PTI, On-street Minibus Termini, Heavy Goods Vehicle and Coach Parking Site, Marine Emissions and Major Point Sources within 4 km

3.6.2.32 AERMOD, the EPD approved air dispersion model, was employed to predict the air quality impact due to the vehicular emissions from the existing bus termini and minibus termini in PTI, on-street minibus termini, heavy goods vehicle and coach parking site, marine emissions, portal emissions and major point sources within 4 km at the representative ASRs.

3.6.2.33 Vehicular and marine emission sources described in Section 3.5.2.1 were modelled as “POINT”, “POINTHOR”, “AREA”, “AREAPOLY”, and “VOLUME” sources. The daily profiles adopted in AERMOD were based on the available information.

3.6.2.34 Hourly meteorological conditions including wind data, temperature, relative humidity, pressure, cloud cover and mixing height are extracted from the WRF meteorological data adopted in the PATH v2.1 model. The minimum wind speed is capped at 1 m/s. The mixing height was capped between 131 meters and 1941 meters according to the observation in Year 2015 by HKO. The height of the input data was assumed to be 9m above ground for the first layer of the WRF data as input. In order to avoid any missing hours misidentified by AERMOD and its associated components, the WRF met data was handled manually to set wind direction between 0° – 0.1° to be 360°. The meteorological data was inputted as on-site data into AERMET (the meteorological pre-processor of AERMOD).

3.6.2.35 Surface characteristic parameters such as albedo, Bowen ratio and surface roughness are required in the AERMET (the meteorological pre-processor of AERMOD). The land use characteristics of the surrounding are classified, and these parameters of each land use are then suggested by AERMET by default according to its land use characteristics. The detailed assumptions are discussed in Appendix 3.10. The AERMET meteorological data are then employed for the AERMOD model run. Flat terrain and urban mode in AERMOD were adopted for this assessment.

Ozone Limiting Method for Short-term Cumulative NO₂ Assessment

3.6.2.36 For the short-term cumulative NO₂ assessment (i.e., predictions of hourly average NO₂ concentration), Ozone Limiting Method (OLM) was adopted for conversion of NO from vehicle-related sources (i.e., emissions from open roads using CALINE4, portals, bus and minibus termini, heavy goods vehicle and coach parking sites) and NOx from industrial and marine sources to NO₂ based on the predicted O₃ level from rerun PATH v2.1. According to the Heathrow Airport EIA report, the initial NO₂/NOx ratios of marine and industrial emission sources are 10%. The NO₂/NOx conversion was calculated as follows:

[NO₂]_predicted = [NO₂]_vehicular + 0.1 ´ [NO_x]_{marine/chimney +} MIN {[NO]_vehicular + 0.9 ´ [NOx]_{marine /chimney}, or (46/48) ´ [O₃]_PATH}

where

[NO₂]_predicted is the predicted NO₂ concentration

[NO₂]_vehicular is the sum of predicted initial NO₂ concentration from open roads, portals, bus and minibus termini, heavy goods vehicle and coach parking sites

[NO_x]_{marine/chimney} is the sum of predicted initial NO_x concentration from the marine and industrial emission sources

[NO]_vehicular is the sum of predicted initial NO concentration from open roads, portals, bus and minibus termini, heavy goods vehicle and coach parking sites

MIN means the minimum of the two values within the brackets

[O₃]_PATH is the representative O₃ from rerun PATH concentration (from other contribution)

(46/48) is the molecular weight of NO₂ divided by the molecular weight of O₃

Jenkin Method for Long-term Cumulative NO₂ Assessment

3.6.2.37 For the long-term cumulative NO₂ assessment (i.e., predictions of annual average NO₂ concentration). Jenkin method was adopted for the conversion of cumulative NO_x to NO₂ by using the functional form of an annual mean of NO₂-to-NO_x with reference to the Review of Methods for NO to NO₂ Conversion in plumes at short ranges[2]. The mentioned functional form is referenced from Jenkin, 2004a[3] and is presented as follows:

where

[NO₂] is the NO₂ concentration

[NO_x] is the NOx concentration

[OX] is the sum of NO₂ concentration and O₃ concentration (i.e. [OX] = [NO₂] + [O₃])

J is the photolysis rate of NO₂

k is the rate coefficient for reaction between NO and O₃

3.6.2.38 The above functional form was used to analyse the annual mean data obtained from EPD’s air quality monitoring stations including Tsuen Wan general station and on-site measurement data on Tsuen Wan Road. The functional form curve would fit the annual mean data when [OX] = 55.0 ppb and J/k = 13.5 ppb. The obtained functional form curve was adopted for the cumulative annual average NO_x to NO₂ conversion. As shown in Appendix 3.11, the curve is slightly higher than all the annual mean data obtained from AQMS and on-site measurement data, underestimation of the annual average NO₂ concentration is not expected. The cumulative annual average NO_x to NO₂ conversion equation for this assessment was calculated as follows:

where

[NO₂] _c is the predicted cumulative NO₂ concentration in ppb

[NO_x] _c is the predicted cumulative NO_x concentration (i.e., the sum of the total predicted NOx concentration from CALINE4, AERMOD and PATH v2.1) in ppb

Cumulative Air Quality Impact

3.6.2.39 The PATH v2.1 model output was added to the sum of the CALINE4 and AERMOD model results sequentially on an hour-to-hour basis to derive the short-term and long-term cumulative impacts at the ASRs for the three assessment scenarios. Cumulative average predictions at each ASR amongst 8760 hours were ranked by highest concentration and compared with the maximum allowable concentration to determine the number of exceedances throughout a year. The air quality impact upon ASRs was evaluated by number of exceedances per annum against the AQO.

3.6.2.40 With reference to the EPD’s Guidelines on Choice of Models and Model Parameters, PATH v2.1’s outputs of RSP and FSP concentrations are adjusted as follows:

· 10^th highest daily RSP concentration: add 11.0 µg/m³

· Annual RSP concentration: add 10.3 µg/m³

· Annual FSP concentration: add 3.5 µg/m³

3.7 Prediction and Evaluation of Environmental Impacts

3.7.1 Construction Phase

3.7.1.1 As mentioned in Section 3.5.1.1 to Section 3.5.1.3, the potential fugitive dust nuisance during the construction phase should be limited due to the small scale and nature of the construction works, and construction activities would not be conducted concurrently at different work location. Hence, there would be no significant dust emission from the works area to the surrounding ASRs and adverse construction dust impact to surrounding ASRs is not anticipated. Nevertheless, dust suppression measures recommended in Section 3.8.1 and mitigation measures stipulated in Air Pollution Control (Construction Dust) Regulation will be implemented to minimize the potential dust emission from the construction of the Project.

3.7.1.2 As mentioned in Section 3.5.1.3. the emissions from PMEs are considered relatively small. Hence, adverse air quality impact arising from the use of PME to the surrounding ASRs is not anticipated.

3.7.2 Operation Phase

3.7.2.1 The cumulative air quality impacts at the representative ASRs have been evaluated. The predicted cumulative air quality impacts at the representative ASRs for the Without Project Scenario, With Project (without DNR) and With Project (with DNR) are presented in Table 3.7, Table 3.8 and Table 3.9, respectively. The detailed assessment results for these scenarios are presented in Appendix 3.12, Appendix 3.13 and Appendix 3.14.

3.7.2.2 According to the predicted results, the predictions under without Project, with Project (without DNR), and with Project (with DNR) scenarios indicated that the 10^th highest daily average and the annual average of RSP, the 19^th highest daily average and the annual average of FSP and the 19^th highest hourly average of NO₂ concentration, at all representative ASRs would comply with the respective AQOs. However, some exceedances were found for the annual average NO₂ concentration. A total of 11 ASRs would exceed the AQO for the annual average NO₂ under Without Project Scenario, while a total of 3 ASRs would exceed the AQO for the annual average NO₂ under With Project (without DNR) Scenario, and a total of 5 ASRs would exceed the AQO for the annual average NO₂ under With Project (With DNR) Scenario.

Table 3.7 Predicted Cumulative Concentrations at Representative Air Sensitive

Receivers under Without Project Scenario

ASR	NO2 Concentration (µg/m^3)		RSP Concentration (µg/m^3)		FSP Concentration (µg/m^3)
	19^th Highest Hourly Average	Annual Average	10^th Highest Daily Average	Annual Average	19^th Highest Daily Average	Annual Average
AQO	200	40	100	50	50	25
A1	121 - 134	19.88 - 26.91	59 - 60	26 - 27	32	14 - 15
A2	123 - 138	20.37 - 26.45	59 - 60	26 - 27	32	14 - 15
A3	110 - 126	15.06 - 22.19	59	26	32	14
A4	110 - 147	15.59 - 29.2	59 - 60	26 - 27	32	14 - 15
A5	110 - 132	15.51 - 23.37	59	26	32	14
A6	111 - 143	15.54 - 26.21	59 - 60	26 - 27	32	14 - 15
A7	148	-	60	-	33	-
A8a	111 - 148	15.56 - 28.96	59 - 60	26 - 27	32 - 33	14 - 15
A8b	111 - 140	15.53 - 24.24	59	26	32	14
A9	164	-	60	-	33	-
A10	151	28.82	59	27	32	15
A11	109 - 140	14.42 - 26.27	59	26 - 27	32	14 - 15
A12	115 - 142	17.94 - 26.52	59	26 - 27	32	14 - 15
A13	110 - 140	15.4 - 25.71	59	26 - 27	32	14 - 15
A14	111 - 140	15.56 - 26.3	59	26 - 27	32	14 - 15
A15	108 - 136	14.1 - 24.03	59	26	32	14
A16	108 - 136	14.19 - 24.71	59	26	32	14
A17	110 - 140	15.79 - 25.76	59	26 - 27	32	14 - 15
A18	110 - 147	15.62 - 28.25	59	26 - 27	32	14 - 15
A19	108 - 137	14.38 - 24.19	59	26	32	14 - 15
A20	109 - 151	14.39 - 28.56	59	26 - 27	32	14 - 15
A21	109 - 152	14.3 - 32.05	59 - 60	26 - 27	32 - 33	14 - 15
A22	110 - 137	15.94 - 25.87	59	26 - 27	32	14 - 15
A23	111 - 137	16.33 - 25.9	59	26 - 27	32	14 - 15
A24	110 - 141	15.65 - 27.14	59	26 - 27	32	14 - 15
A25	157	-	61	-	33	-
A26	136 - 145	21.77 - 28.99	60 - 61	27	32	15
A27	114 - 144	15.99 - 29.52	60 - 61	27	32	14 - 15
A28a	145 - 149	28.02 - 31.04	60 - 61	27	32	15
A28b	149 - 159	28.78 - 32.78	61	27	32	15
A29	113 - 144	15.74 - 28.65	60 - 61	26 - 27	32	14 - 15
A30	113 - 150	15.75 - 31.26	60 - 61	27	32	14 - 15
A31	159	-	61	-	33	-
A32	112 - 154	15.26 - 33.19	60 - 61	26 - 27	32 - 33	14 - 15
A33	113 - 158	15.76 - 34.03	60 - 61	27	32 - 33	14 - 15
A34	116 - 161	16.9 - 34.99	60 - 61	27 - 28	32 - 33	14 - 15
A35	120 - 164	18.4 - 36.43	60 - 61	27 - 28	32 - 33	14 - 15
A36	113 - 140	15.17 - 22.59	60	26 - 27	32	14 - 15
A37	113 - 140	15.18 - 22.63	60	26 - 27	32	14 - 15
A38	113 - 138	15.19 - 22.52	60	26 - 27	32	14 - 15
A39	113 - 141	15.2 - 22.6	60	26 - 27	32	14 - 15
A40	123 - 161	18.19 - 33.66	60 - 61	27	32 - 33	14 - 15
A41	139 - 181	22.77 - 37.49	60 - 61	27 - 28	32	15
A42	177	-	61	-	33	-
A43	139 - 170	23.5 - 38.78	60 - 62	27 - 28	32 - 33	15 - 16
A44	113 - 169	15.53 - 37.34	60 - 62	26 - 28	32 - 33	14 - 15
A45	133 - 145	20.98 - 26.76	60	27	32	15
A46	111 - 153	14.9 - 29.47	60 - 61	26 - 27	32	14 - 15
A47	111 - 144	14.57 - 27.61	60	26 - 27	32	14 - 15
A48	111 - 143	14.99 - 26.28	60	26 - 27	32	14 - 15
A49	111 - 144	14.77 - 27.56	60 - 61	26 - 27	32	14 - 15
A50	141 - 163	23.26 - 32.02	60 - 61	27	32	15
A51	124 - 145	19.63 - 27.83	60	27	32	15
A52	126 - 171	19.65 - 33.23	60	27 - 28	32	15
A53	164	-	61	-	33	-
A54	168	-	61	-	33	-
A55	151 - 173	26.47 - 38.47	61	27	33	15
A56	128 - 157	17.82 - 31.51	60 - 61	26 - 27	32 - 33	14 - 15
A57	133 - 168	19.95 - 35.81	60 - 61	27	32 - 33	15
A58	143 - 167	24.58 - 35.38	60 - 61	27 - 28	33 - 34	15 - 16
A59	136 - 168	23.62 - 35.81	60 - 62	27 - 29	33 - 35	15 - 17
A60	131 - 174	19.73 - 36.36	60 - 61	27	32 - 33	14 - 15
A61	132 - 174	20.41 - 38.03	60 - 61	27 - 28	32 - 33	15
A62	128 - 144	17.93 - 26.36	60	26 - 27	32 - 33	14 - 15
A63	132 - 170	20.62 - 35.18	60 - 61	27	32 - 33	15
A64	131 - 181	19.57 - 35.84	60 - 61	26 - 27	32 - 33	14 - 15
A65	132 - 187	20.28 - 38.88	60 - 61	27	32 - 33	15
A66a	138 - 190	22.19 - 41.26	60 - 61	27 - 28	32 - 33	15
A66b	137 - 184	22.33 - 39.15	60 - 61	27	32 - 33	15
A67	131 - 179	19.37 - 39.23	60 - 61	26 - 27	32 - 33	14 - 15
A68	128 - 165	17.75 - 34.89	60 - 61	26 - 27	32 - 33	14 - 15
A69	139 - 162	23.78 - 31.39	60 - 61	27	32 - 33	15
A70	128 - 159	18.42 - 30.85	60 - 61	26 - 27	32 - 33	14 - 15
A71a	133 - 181	20.88 - 40.28	60 - 61	27	32 - 33	15
A71b	133 - 192	20.76 - 41.56	60 - 61	27 - 28	32 - 33	15
A72	135 - 180	21.95 - 39.26	60 - 61	27 - 28	32 - 33	15
A73	131 - 182	19.79 - 41.04	60 - 61	27 - 28	32 - 33	14 - 15
A74	132 - 163	20.55 - 35.03	60 - 61	27	32 - 33	15
A75a	128 - 169	19.12 - 35.33	60 - 61	26 - 27	32 - 33	14 - 15
A75b	128 - 175	19.18 - 36.29	60 - 61	26 - 27	32 - 33	14 - 15
A76	143 - 150	23.91 - 32.71	60 - 61	27	33	15
A77	128 - 184	17.74 - 43.08	60 - 62	26 - 28	32 - 34	14 - 16
A78	177	-	61	-	34	-
A79	134 - 153	20.44 - 30.77	60 - 61	27	32 - 33	15
A80	130 - 158	19.18 - 35.01	60 - 61	26 - 27	32 - 34	14 - 15
A81	131 - 156	19.11 - 34.76	60 - 61	26 - 27	32 - 33	14 - 15
A82	131 - 161	19.09 - 37.56	60 - 61	26 - 28	32 - 34	14 - 15
A83	147 - 162	30.33 - 38.71	61	27 - 28	33 - 34	15 - 16
A84	132 - 165	19.21 - 41.13	60 - 62	26 - 28	32 - 34	14 - 16
A85	132 - 161	19.21 - 38.57	60 - 61	26 - 28	32 - 34	14 - 15
A86	132 - 162	19.19 - 37.91	60 - 61	26 - 28	32 - 34	14 - 15
A87	131 - 161	19.16 - 38.18	60 - 61	26 - 27	32 - 34	14 - 15
A88	148 - 162	30.23 - 38.08	61	27	33 - 34	15
A89a	128 - 154	18.46 - 30.53	60 - 61	26 - 27	32 - 33	14 - 15
A89b	128 - 154	18.46 - 30.52	60 - 61	26 - 27	32 - 33	14 - 15
A90	128 - 154	18.47 - 30.26	60 - 61	26 - 27	32 - 33	14 - 15
A91	128 - 153	18.31 - 30	60 - 61	26 - 27	32 - 33	14 - 15
A92	133 - 158	19.92 - 35.04	60 - 61	27	32 - 33	14 - 15
A93	128 - 152	18.33 - 29.51	60 - 61	26 - 27	32 - 33	14 - 15
A94	146 - 159	27.86 - 35.61	61	27	33 - 34	15
A95	129 - 152	18.35 - 29.06	60 - 61	26 - 27	32 - 33	14 - 15
A96	129 - 152	18.38 - 28.77	60 - 61	26 - 27	32 - 33	14 - 15
A97	129 - 150	18.4 - 28.62	60 - 61	26 - 27	32 - 33	14 - 15
A98	128 - 146	18.19 - 28.36	60 - 61	26 - 27	32 - 33	14 - 15
A99	147 - 160	26.32 - 32.99	61	27	33 - 34	15
A100	128 - 148	18.11 - 28.09	60 - 61	26 - 27	32 - 33	14 - 15
A101	121 - 150	17.27 - 28.82	60 - 61	26 - 27	32 - 33	14 - 15
A102	121 - 178	18.32 - 40.91	60 - 61	26 - 28	32 - 33	14 - 15
A103	122 - 171	18.5 - 35.4	60 - 61	26 - 27	32 - 33	14 - 15
A104	121 - 177	17.61 - 37.77	60 - 61	26 - 27	32 - 33	14 - 15
A105	119 - 141	16.91 - 22.97	60	26 - 27	32	14 - 15
A106	139 - 166	22.55 - 33	61	27	32 - 33	15
A107	136 - 181	21.71 - 36.74	60 - 61	27	32 - 33	15
A108	121 - 168	17.37 - 32.6	60 - 61	26 - 27	32 - 33	14 - 15
A109	124 - 181	18.75 - 34.49	60 - 61	26 - 27	32 - 33	14 - 15
A110	121 - 147	17.53 - 24.61	60	26 - 27	32	14 - 15
A111	120 - 146	17.33 - 24.65	60 - 61	26 - 27	32	14 - 15
A112	119 - 143	17.25 - 23.37	60 - 61	26 - 27	32	14 - 15
A113	121 - 156	17.5 - 31.07	60 - 61	26 - 27	32 - 33	14 - 15
A114	122 - 163	18.33 - 31.33	60 - 61	26 - 27	32 - 33	14 - 15
A115	121 - 174	18.34 - 34.8	60 - 61	27	32 - 33	14 - 15
A116	137 - 145	21.17 - 24.18	60 - 61	27	32	15
A117	121 - 146	18.66 - 24.71	60 - 61	26 - 27	32	14 - 15
A118	124 - 150	19.37 - 27.7	60 - 61	27	32 - 33	14 - 15
A119	137 - 153	22.47 - 27.7	60 - 61	27	32 - 33	15
A120	121 - 153	18.76 - 28.13	60 - 61	26 - 27	32 - 33	14 - 15
A121	120 - 139	17.37 - 22.46	60	26 - 27	32	14 - 15
A122	140 - 152	22.63 - 28.35	60 - 61	27	32 - 33	15
A123	139 - 151	22.5 - 27.48	60 - 61	27	32 - 33	15
A124	122 - 172	19.17 - 31.48	60 - 61	26 - 27	32 - 33	14 - 15
A125	136 - 172	22.6 - 34.48	61	27	32 - 33	15
A126	122 - 184	19.25 - 44.72	61 - 63	27 - 28	32 - 34	15 - 16
A127	121 - 157	18.69 - 30.01	60 - 61	27	32 - 33	14 - 15
A128	133 - 168	21.59 - 36.71	61 - 62	27	32 - 34	15
A129	170	34.03	61	27	33	15
A130	136 - 152	22.03 - 30.1	61	27	33	15
A131	136 - 167	21.85 - 34.28	61	27	33	15
A132	138 - 156	22.4 - 31.12	61	27	33	15
A133	142 - 165	23.96 - 35.54	61 - 62	27	33	15
A134	136 - 169	21.64 - 36.37	61 - 62	27	33	15
A135	138 - 163	22.65 - 34.32	61 - 62	27	33	15
A136	171	-	61	-	33	-
A137	137 - 162	22.5 - 34.02	61 - 62	27	33	15
A138	136 - 158	21.87 - 32.77	61 - 62	27	33	15
A139a	137 - 167	22.1 - 36.86	61 - 62	27	33	15
A139b	137 - 167	22.07 - 36.01	61	27	33	15
A140	138 - 166	22.21 - 34.97	61	27	33	15
A141	136 - 163	21.87 - 33.64	61	27	33	15
A142	135 - 175	20.91 - 41.6	61 - 62	27	33 - 34	15
A143	134 - 150	20.71 - 26.77	61	27	33	15
A144	136 - 176	22.32 - 32.02	61	27	33	15
A145	135 - 158	21.45 - 27.64	61	27	33	15
A146	135 - 165	21.86 - 31.29	61	27	33	15
A147	141 - 159	24.25 - 30.3	61	27	33	15
A148	169 - 173	35.86 - 36.92	62	27	33 - 34	15
A149	135 - 144	21.03 - 27.55	61	27	33	15
A150	134 - 139	20.57 - 22.84	61	26 - 27	33	15
A154	159	-	62	-	34	-
A155	138 - 159	23.12 - 35.94	61 - 62	27	33 - 34	15
A156	136 - 159	22.42 - 36.05	61 - 62	27	33 - 34	15
A157	138 - 154	23.5 - 34.01	61 - 62	27	33 - 34	15
A158	155	-	62	-	34	-
A159	146 - 155	26.21 - 32.31	61 - 62	27	33 - 34	15
A160	136 - 180	22.32 - 41.27	61 - 63	27 - 28	33 - 34	15 - 16
A161	136 - 159	22.34 - 33.23	61 - 62	27	33	15
A162	163 - 188	34.22 - 46.32	62 - 63	27 - 28	34	15 - 16
A163	150 - 154	25.77 - 34.51	61 - 62	27	33 - 34	15

Note:

1. Exceedance of the relevant AQOs is bolded and underlined.

2. Long-term AQOs are not applicable to A7, A9, A25, A31, A42, A53, A54, A78, A136, A154, and A158 in consideration of short retention time at these kinds of uses.

Table 3.8 Predicted Cumulative Concentrations at Representative Air Sensitive Receivers under With Project (Without DNR) Scenario

ASR	NO2 Concentration (µg/m^3)		RSP Concentration (µg/m^3)		FSP Concentration (µg/m^3)
	19^th Highest Hourly Average	Annual Average	10^th Highest Daily Average	Annual Average	19^th Highest Daily Average	Annual Average
AQO	200	40	100	50	50	25
A1	121 - 134	19.78 - 26.82	59 - 60	26 - 27	32	14 - 15
A2	123 - 138	20.27 - 26.35	59 - 60	26 - 27	32	14 - 15
A3	110 - 126	15.02 - 22.06	59	26	32	14
A4	110 - 146	15.53 - 29.09	59 - 60	26 - 27	32	14 - 15
A5	110 - 132	15.45 - 23.2	59	26	32	14
A6	111 - 142	15.48 - 26.02	59 - 60	26 - 27	32	14 - 15
A7	147	-	60	-	33	-
A8a	111 - 144	15.51 - 28.86	59 - 60	26 - 27	32 - 33	14 - 15
A8b	111 - 138	15.47 - 24.02	59	26	32	14
A9	163	-	60	-	33	-
A10	149	28.68	59	27	32	15
A11	109 - 138	14.38 - 26.14	59	26 - 27	32	14 - 15
A12	115 - 140	17.85 - 26.39	59	26 - 27	32	14 - 15
A13	110 - 138	15.33 - 25.57	59	26 - 27	32	14 - 15
A14	111 - 139	15.49 - 26.16	59	26 - 27	32	14 - 15
A15	108 - 133	14.07 - 23.88	59	26	32	14
A16	108 - 135	14.15 - 24.56	59	26	32	14
A17	110 - 137	15.71 - 25.6	59	26 - 27	32	14 - 15
A18	110 - 145	15.54 - 28.1	59	26 - 27	32	14 - 15
A19	108 - 137	14.34 - 24.09	59	26	32	14 - 15
A20	109 - 150	14.35 - 28.47	59	26 - 27	32	14 - 15
A21	109 - 152	14.26 - 31.96	59 - 60	26 - 27	32 - 33	14 - 15
A22	110 - 137	15.87 - 25.78	59	26 - 27	32	14 - 15
A23	111 - 136	16.26 - 25.75	59	26 - 27	32	14 - 15
A24	110 - 140	15.57 - 26.99	59	26 - 27	32	14 - 15
A25	157	-	61	-	33	-
A26	136 - 144	21.65 - 28.87	60 - 61	27	32	15
A27	114 - 144	15.92 - 29.37	60 - 61	27	32	14 - 15
A28a	144 - 147	27.88 - 30.87	60 - 61	27	32	15
A28b	148 - 157	28.66 - 32.63	61	27	32	15
A29	113 - 144	15.68 - 28.5	60 - 61	26 - 27	32	14 - 15
A30	113 - 148	15.69 - 31.07	60 - 61	26 - 27	32	14 - 15
A31	158	-	61	-	33	-
A32	112 - 153	15.21 - 32.93	60 - 61	26 - 27	32 - 33	14 - 15
A33	113 - 157	15.7 - 33.76	60 - 61	27	32 - 33	14 - 15
A34	116 - 159	16.8 - 34.69	60 - 61	27 - 28	32 - 33	14 - 15
A35	119 - 163	18.27 - 36.15	60 - 61	27 - 28	32 - 33	14 - 15
A36	112 - 138	15.13 - 22.41	60	26 - 27	32	14 - 15
A37	112 - 138	15.14 - 22.47	60	26 - 27	32	14 - 15
A38	112 - 137	15.15 - 22.37	60	26 - 27	32	14 - 15
A39	113 - 140	15.16 - 22.48	60	26 - 27	32	14 - 15
A40	123 - 160	18.1 - 33.57	60 - 61	27	32 - 33	14 - 15
A41	139 - 181	22.66 - 37.33	60 - 61	27 - 28	32	15
A42	177	-	61	-	33	-
A43	139 - 169	23.33 - 38.6	60 - 62	27 - 28	32 - 33	15 - 16
A44	113 - 168	15.46 - 37.19	60 - 62	26 - 28	32 - 33	14 - 15
A45	133 - 145	20.79 - 26.56	60	27	32	15
A46	111 - 152	14.87 - 29.29	60 - 61	26 - 27	32	14 - 15
A47	111 - 144	14.56 - 27.39	60	26 - 27	32	14 - 15
A48	111 - 142	14.96 - 26.04	60	26 - 27	32	14 - 15
A49	111 - 143	14.75 - 27.31	60 - 61	26 - 27	32	14 - 15
A50	139 - 161	23 - 31.78	60 - 61	27	32	15
A51	123 - 145	19.43 - 27.59	60	27	32	15
A52	127 - 170	19.48 - 33	60	27 - 28	32	15
A53	164	-	61	-	33	-
A54	168	-	61	-	33	-
A55	146 - 172	26.19 - 38.3	61	27	33	15
A56	128 - 154	17.8 - 31.29	60 - 61	26 - 27	32 - 33	14 - 15
A57	132 - 166	19.85 - 35.6	60 - 61	27	32 - 33	15
A58	141 - 167	24.29 - 35.15	60 - 61	27 - 28	33 - 34	15 - 16
A59	135 - 168	23.44 - 35.61	60 - 62	27 - 29	33 - 35	15 - 17
A60	131 - 170	19.64 - 35.82	60 - 61	27	32 - 33	14 - 15
A61	132 - 173	20.24 - 37.82	60 - 61	27 - 28	32 - 33	15
A62	128 - 144	17.91 - 25.96	60	26 - 27	32 - 33	14 - 15
A63	132 - 166	20.48 - 34.44	60 - 61	27	32 - 33	15
A64	131 - 170	19.48 - 34.57	60 - 61	26 - 27	32 - 33	14 - 15
A65	132 - 180	20.15 - 37.56	60 - 61	27	32 - 33	15
A66a	135 - 184	21.94 - 39.62	60 - 61	27 - 28	32 - 33	15
A66b	135 - 178	22.07 - 37.75	60 - 61	27	32 - 33	15
A67	131 - 175	19.28 - 38.38	60 - 61	26 - 27	32 - 33	14 - 15
A68	128 - 163	17.74 - 34.4	60 - 61	26 - 27	32 - 33	14 - 15
A69	139 - 162	23.51 - 31.09	60 - 61	27	32 - 33	15
A70	128 - 153	18.38 - 29.89	60 - 61	26 - 27	32 - 33	14 - 15
A71a	133 - 173	20.72 - 38.78	60 - 61	27	32 - 33	15
A71b	133 - 181	20.6 - 39.85	60 - 61	27 - 28	32 - 33	15
A72	134 - 174	21.69 - 37.73	60 - 61	27	32 - 33	15
A73	131 - 173	19.67 - 39.63	60 - 61	27 - 28	32 - 33	14 - 15
A74	132 - 155	20.37 - 33.99	60 - 61	27	32 - 33	15
A75a	128 - 161	19.06 - 33.85	60 - 61	26 - 27	32 - 33	14 - 15
A75b	128 - 165	19.13 - 34.71	60 - 61	26 - 27	32 - 33	14 - 15
A76	142 - 150	23.56 - 30.69	60 - 61	27	33	15
A77	128 - 167	17.73 - 38.41	60 - 61	26 - 28	32 - 34	14 - 16
A78	163	-	61	-	34	-
A79	134 - 152	20.31 - 30.05	60 - 61	27	32 - 33	15
A80	130 - 157	19.11 - 35.48	60 - 61	26 - 27	32 - 34	14 - 15
A81	130 - 156	19.05 - 34.69	60 - 61	26 - 27	32 - 33	14 - 15
A82	130 - 164	19.03 - 39.22	60 - 62	26 - 28	32 - 34	14 - 16
A83	145 - 163	30.2 - 39.92	61 - 62	27 - 28	33 - 34	15 - 16
A84	132 - 166	19.15 - 41.24	60 - 62	26 - 28	32 - 34	14 - 16
A85	132 - 166	19.15 - 39.64	60 - 61	26 - 28	32 - 34	14 - 16
A86	132 - 163	19.13 - 38.35	60 - 61	26 - 28	32 - 34	14 - 15
A87	131 - 161	19.1 - 38.12	60 - 61	26 - 28	32 - 34	14 - 15
A88	146 - 160	29.68 - 37.73	61	27	33 - 34	15
A89a	128 - 151	18.43 - 29.53	60 - 61	26 - 27	32 - 33	14 - 15
A89b	128 - 151	18.43 - 29.5	60 - 61	26 - 27	32 - 33	14 - 15
A90	128 - 151	18.44 - 29.31	60 - 61	26 - 27	32 - 33	14 - 15
A91	128 - 150	18.29 - 29.11	60 - 61	26 - 27	32 - 33	14 - 15
A92	133 - 158	19.8 - 34.5	60 - 61	27	32 - 33	14 - 15
A93	128 - 151	18.3 - 28.83	60 - 61	26 - 27	32 - 33	14 - 15
A94	146 - 158	27.42 - 35.13	61	27	33 - 34	15
A95	129 - 149	18.33 - 28.61	60 - 61	26 - 27	32 - 33	14 - 15
A96	129 - 148	18.35 - 28.4	60 - 61	26 - 27	32 - 33	14 - 15
A97	129 - 148	18.37 - 28.27	60 - 61	26 - 27	32 - 33	14 - 15
A98	128 - 146	18.16 - 28.05	60 - 61	26 - 27	32 - 33	14 - 15
A99	145 - 159	26.05 - 33.71	61	27	33 - 34	15
A100	128 - 146	18.09 - 27.78	60 - 61	26 - 27	32 - 33	14 - 15
A101	121 - 147	17.25 - 28.11	60 - 61	26 - 27	32 - 33	14 - 15
A102	121 - 173	18.23 - 40.1	60 - 61	26 - 28	32 - 33	14 - 15
A103	122 - 165	18.38 - 35	60 - 61	26 - 27	32 - 33	14 - 15
A104	121 - 174	17.55 - 37.47	60 - 61	26 - 27	32 - 33	14 - 15
A105	119 - 139	16.88 - 22.67	60	26 - 27	32	14 - 15
A106	137 - 165	22.25 - 32.7	61	27	32 - 33	15
A107	136 - 181	21.47 - 36.48	60 - 61	27	32 - 33	15
A108	121 - 162	17.31 - 32.35	60 - 61	26 - 27	32 - 33	14 - 15
A109	123 - 180	18.62 - 34.32	60 - 61	26 - 27	32 - 33	14 - 15
A110	121 - 148	17.47 - 24.42	60	26 - 27	32	14 - 15
A111	120 - 146	17.28 - 24.45	60 - 61	26 - 27	32	14 - 15
A112	119 - 142	17.22 - 23.02	60 - 61	26 - 27	32	14 - 15
A113	121 - 155	17.48 - 30.22	60 - 61	26 - 27	32 - 33	14 - 15
A114	122 - 154	18.28 - 30.78	60 - 61	26 - 27	32 - 33	14 - 15
A115	121 - 162	18.34 - 32.01	60 - 61	27	32 - 33	14 - 15
A116	135 - 143	21 - 24	60 - 61	27	32	15
A117	121 - 146	18.55 - 24.46	60 - 61	26 - 27	32	14 - 15
A118	123 - 149	19.18 - 27.2	60 - 61	27	32 - 33	14 - 15
A119	136 - 151	21.99 - 27.05	60 - 61	27	32 - 33	15
A120	121 - 151	18.66 - 27.41	60 - 61	26 - 27	32 - 33	14 - 15
A121	120 - 139	17.36 - 22.3	60	26 - 27	32	14 - 15
A122	140 - 153	22.55 - 28.18	60 - 61	27	32 - 33	15
A123	140 - 152	22.36 - 27.32	60 - 61	27	32 - 33	15
A124	122 - 170	19.06 - 31	60 - 61	26 - 27	32 - 33	14 - 15
A125	136 - 162	22.04 - 33.3	61	27	32 - 33	15
A126	122 - 157	19.19 - 36.34	61 - 62	27 - 28	32 - 34	14 - 15
A127	121 - 150	18.67 - 27.95	60 - 61	27	32 - 33	14 - 15
A128	133 - 157	21.34 - 32.68	61 - 62	27	32 - 33	15
A129	170	33.63	61	27	33	15
A130	136 - 152	22.03 - 29.32	61	27	33	15
A131	136 - 162	21.84 - 33.24	61	27	33	15
A132	138 - 156	22.4 - 30.95	61	27	33	15
A133	143 - 169	23.95 - 35.25	61 - 62	27	33	15
A134	136 - 170	21.64 - 36.11	61 - 62	27	33	15
A135	138 - 163	22.65 - 34.14	61 - 62	27	33	15
A136	172	-	61	-	33	-
A137	137 - 163	22.5 - 33.96	61 - 62	27	33	15
A138	136 - 159	21.87 - 32.69	61 - 62	27	33	15
A139a	137 - 167	22.1 - 36.69	61 - 62	27	33	15
A139b	137 - 167	22.06 - 35.67	61	27	33	15
A140	138 - 167	22.21 - 34.72	61	27	33	15
A141	136 - 164	21.86 - 33.39	61	27	33	15
A142	135 - 173	20.9 - 41.47	61 - 62	27	33 - 34	15
A143	134 - 150	20.71 - 26.76	61	27	33	15
A144	136 - 176	22.32 - 32.12	61	27	33	15
A145	135 - 159	21.45 - 27.66	61	27	33	15
A146	135 - 164	21.86 - 31.34	61	27	33	15
A147	141 - 158	24.26 - 30.31	61	27	33	15
A148	170 - 173	35.86 - 37.18	62	27 - 28	33 - 34	15
A149	135 - 144	21.03 - 27.55	61	27	33	15
A150	133 - 139	20.57 - 22.84	61	26 - 27	33	15
A154	160	-	62	-	34	-
A155	138 - 159	23.14 - 35.91	61 - 62	27	33 - 34	15
A156	136 - 159	22.42 - 35.97	61 - 62	27	33 - 34	15
A157	138 - 155	23.52 - 34.06	61 - 62	27	33 - 34	15
A158	155	-	62	-	34	-
A159	146 - 155	25.92 - 31.34	61 - 62	27	33 - 34	15
A160	136 - 161	22.32 - 36.92	61 - 62	27	33 - 34	15
A161	136 - 155	22.34 - 31.2	61 - 62	27	33	15
A162	156 - 162	31.85 - 39.09	62 - 63	27 - 28	34	15 - 16
A163	149 - 153	25.52 - 32.44	61 - 62	27	33 - 34	15

Note:

1. Exceedance of the relevant AQOs is bolded and underlined.

2. Long-term AQO are not applicable to A7, A9, A25, A31, A42, A53, A54, A78, A136, A154, and A158 in consideration of short retention time at these kinds of uses.

Table 3.9 Predicted Cumulative Concentrations at Representative Air Sensitive Receivers under With Project (With DNR) Scenario

ASR	NO2 Concentration (µg/m^3)		RSP Concentration (µg/m^3)		FSP Concentration (µg/m^3)
	19^th Highest Hourly Average	Annual Average	10^th Highest Daily Average	Annual Average	19^th Highest Daily Average	Annual Average
AQO	200	40	100	50	50	25
A1	121 - 134	19.76 - 26.79	59 - 60	26 - 27	32	14 - 15
A2	123 - 138	20.25 - 26.32	59 - 60	26 - 27	32	14 - 15
A3	110 - 125	15.01 - 22.04	59	26	32	14
A4	110 - 146	15.52 - 29.07	59 - 60	26 - 27	32	14 - 15
A5	110 - 132	15.44 - 23.18	59	26	32	14
A6	111 - 142	15.47 - 26.01	59 - 60	26 - 27	32	14 - 15
A7	147	-	60	-	33	-
A8a	111 - 144	15.49 - 28.85	59 - 60	26 - 27	32 - 33	14 - 15
A8b	111 - 138	15.45 - 24.01	59	26	32	14
A9	163	-	60	-	33	-
A10	149	28.68	59	27	32	15
A11	108 - 137	14.38 - 26.14	59	26 - 27	32	14 - 15
A12	115 - 140	17.82 - 26.4	59	26 - 27	32	14 - 15
A13	110 - 137	15.32 - 25.58	59	26 - 27	32	14 - 15
A14	111 - 138	15.47 - 26.17	59	26 - 27	32	14 - 15
A15	108 - 133	14.07 - 23.89	59	26	32	14
A16	108 - 135	14.15 - 24.57	59	26	32	14
A17	110 - 137	15.7 - 25.62	59	26 - 27	32	14 - 15
A18	110 - 146	15.54 - 28.13	59	26 - 27	32	14 - 15
A19	108 - 137	14.34 - 24.11	59	26	32	14 - 15
A20	109 - 150	14.35 - 28.48	59	26 - 27	32	14 - 15
A21	109 - 152	14.26 - 31.97	59 - 60	26 - 27	32 - 33	14 - 15
A22	110 - 137	15.85 - 25.79	59	26 - 27	32	14 - 15
A23	111 - 137	16.24 - 25.77	59	26 - 27	32	14 - 15
A24	110 - 141	15.56 - 27.01	59	26 - 27	32	14 - 15
A25	157	-	61	-	33	-
A26	136 - 144	21.6 - 28.78	60	27	32	15
A27	114 - 144	15.93 - 29.27	60 - 61	27	32	14 - 15
A28a	143 - 145	27.79 - 30.78	60 - 61	27	32	15
A28b	147 - 156	28.57 - 32.54	61	27	32	15
A29	113 - 143	15.69 - 28.38	60 - 61	26 - 27	32	14 - 15
A30	113 - 150	15.7 - 30.94	60 - 61	26 - 27	32	14 - 15
A31	156	-	61	-	33	-
A32	112 - 154	15.21 - 32.82	60 - 61	26 - 27	32 - 33	14 - 15
A33	113 - 154	15.7 - 33.47	60 - 61	27	32 - 33	14 - 15
A34	116 - 158	16.81 - 34.35	60 - 61	27	32 - 33	14 - 15
A35	120 - 162	18.3 - 36.04	60 - 61	27 - 28	32 - 33	14 - 15
A36	112 - 135	15.13 - 22.39	60	26 - 27	32	14 - 15
A37	112 - 135	15.14 - 22.47	60	26 - 27	32	14 - 15
A38	113 - 134	15.16 - 22.34	60	26 - 27	32	14 - 15
A39	113 - 136	15.17 - 22.43	60	26 - 27	32	14 - 15
A40	123 - 160	18.08 - 33.55	60 - 61	27	32 - 33	14 - 15
A41	138 - 178	22.63 - 37.31	60 - 61	27 - 28	32	15
A42	177	-	61	-	33	-
A43	139 - 170	23.34 - 38.62	60 - 62	27 - 28	32 - 33	15 - 16
A44	113 - 168	15.47 - 37.2	60 - 62	26 - 28	32 - 33	14 - 15
A45	133 - 145	20.81 - 26.62	60	27	32	15
A46	111 - 152	14.87 - 29.36	60 - 61	26 - 27	32	14 - 15
A47	111 - 143	14.56 - 27.56	60 - 61	26 - 27	32	14 - 15
A48	111 - 142	14.96 - 26.18	60	26 - 27	32	14 - 15
A49	111 - 144	14.75 - 27.46	60 - 61	26 - 27	32	14 - 15
A50	140 - 162	23.05 - 31.85	60 - 61	27	32	15
A51	123 - 145	19.44 - 27.62	60	27	32	15
A52	127 - 170	19.49 - 33.02	60	27 - 28	32	15
A53	161	-	61	-	33	-
A54	165	-	61	-	33	-
A55	147 - 173	26.15 - 38.44	61	27	33	15
A56	128 - 158	17.81 - 31.46	60 - 61	26 - 27	32 - 33	14 - 15
A57	132 - 167	19.86 - 35.91	60 - 61	27	32 - 33	15
A58	141 - 168	24.25 - 35.61	60 - 61	27 - 28	33 - 34	15 - 16
A59	135 - 168	23.44 - 35.59	60 - 62	27 - 29	33 - 35	15 - 17
A60	131 - 171	19.65 - 36.24	60 - 61	27	32 - 33	14 - 15
A61	132 - 173	20.24 - 37.9	60 - 61	27 - 28	32 - 33	15
A62	128 - 144	17.91 - 26.03	60	26 - 27	32 - 33	14 - 15
A63	132 - 167	20.49 - 34.74	60 - 61	27	32 - 33	15
A64	131 - 179	19.49 - 38.09	60 - 61	26 - 28	32 - 33	14 - 16
A65	132 - 184	20.16 - 38.14	60 - 61	27	32 - 33	15
A66a	135 - 191	21.96 - 40.2	60 - 61	27 - 28	32 - 33	15
A66b	135 - 178	22.07 - 38.19	60 - 61	27	32 - 33	15
A67	131 - 175	19.28 - 38.55	60 - 61	26 - 27	32 - 33	14 - 15
A68	128 - 163	17.74 - 34.46	60 - 61	26 - 27	32 - 33	14 - 15
A69	139 - 162	23.53 - 31.13	60 - 61	27	32 - 33	15
A70	128 - 153	18.39 - 30.06	60 - 61	26 - 27	32 - 33	14 - 15
A71a	133 - 173	20.73 - 39.18	60 - 61	27	32 - 33	15
A71b	133 - 184	20.6 - 40.18	60 - 61	27 - 28	32 - 33	15
A72	134 - 174	21.7 - 37.78	60 - 61	27	32 - 33	15
A73	131 - 173	19.68 - 39.65	60 - 61	27 - 28	32 - 33	14 - 15
A74	132 - 155	20.38 - 34	60 - 61	27	32 - 33	15
A75a	128 - 161	19.06 - 33.83	60 - 61	26 - 27	32 - 33	14 - 15
A75b	128 - 165	19.13 - 34.69	60 - 61	26 - 27	32 - 33	14 - 15
A76	142 - 150	23.57 - 30.7	60 - 61	27	33	15
A77	128 - 167	17.73 - 38.83	60 - 61	26 - 28	32 - 34	14 - 16
A78	163	-	61	-	34	-
A79	134 - 152	20.31 - 30.03	60 - 61	27	32 - 33	15
A80	130 - 159	19.12 - 35.06	60 - 61	26 - 27	32 - 34	14 - 15
A81	130 - 156	19.05 - 34.51	60 - 61	26 - 27	32 - 33	14 - 15
A82	130 - 157	19.03 - 36.27	60 - 61	26 - 27	32 - 34	14 - 15
A83	146 - 162	30.3 - 38.23	61	27 - 28	33 - 34	15
A84	132 - 165	19.15 - 40.81	60 - 62	26 - 28	32 - 34	14 - 16
A85	132 - 161	19.15 - 37.91	60 - 61	26 - 28	32 - 34	14 - 15
A86	132 - 162	19.13 - 37.55	60 - 61	26 - 28	32 - 34	14 - 15
A87	131 - 161	19.11 - 37.78	60 - 61	26 - 27	32 - 34	14 - 15
A88	146 - 160	29.67 - 37.51	61	27	33	15
A89a	128 - 151	18.44 - 29.4	60 - 61	26 - 27	32 - 33	14 - 15
A89b	128 - 151	18.43 - 29.37	60 - 61	26 - 27	32 - 33	14 - 15
A90	128 - 151	18.44 - 29.19	60 - 61	26 - 27	32 - 33	14 - 15
A91	128 - 149	18.29 - 29.01	60 - 61	26 - 27	32 - 33	14 - 15
A92	133 - 158	19.81 - 34.34	60 - 61	27	32 - 33	14 - 15
A93	128 - 148	18.31 - 28.82	60 - 61	26 - 27	32 - 33	14 - 15
A94	146 - 158	27.34 - 34.97	61	27	33 - 34	15
A95	129 - 147	18.33 - 28.54	60 - 61	26 - 27	32 - 33	14 - 15
A96	129 - 147	18.36 - 28.36	60 - 61	26 - 27	32 - 33	14 - 15
A97	129 - 147	18.37 - 28.31	60 - 61	26 - 27	32 - 33	14 - 15
A98	128 - 144	18.17 - 27.92	60 - 61	26 - 27	32 - 33	14 - 15
A99	143 - 152	26.19 - 32.02	61	27	33	15
A100	128 - 146	18.09 - 27.66	60 - 61	26 - 27	32 - 33	14 - 15
A101	121 - 147	17.25 - 28.11	60 - 61	26 - 27	32 - 33	14 - 15
A102	121 - 173	18.23 - 40.11	60 - 61	26 - 28	32 - 33	14 - 15
A103	122 - 165	18.38 - 35.01	60 - 61	26 - 27	32 - 33	14 - 15
A104	121 - 174	17.55 - 37.48	60 - 61	26 - 27	32 - 33	14 - 15
A105	119 - 139	16.89 - 22.67	60	26 - 27	32	14 - 15
A106	137 - 165	22.26 - 32.72	61	27	32 - 33	15
A107	136 - 181	21.47 - 36.49	60 - 61	27	32 - 33	15
A108	121 - 162	17.31 - 32.36	60 - 61	26 - 27	32 - 33	14 - 15
A109	123 - 180	18.62 - 34.32	60 - 61	26 - 27	32 - 33	14 - 15
A110	121 - 148	17.47 - 24.42	60	26 - 27	32	14 - 15
A111	120 - 146	17.28 - 24.46	60 - 61	26 - 27	32	14 - 15
A112	119 - 142	17.22 - 23.03	60 - 61	26 - 27	32	14 - 15
A113	121 - 155	17.48 - 30.21	60 - 61	26 - 27	32 - 33	14 - 15
A114	122 - 154	18.28 - 30.74	60 - 61	26 - 27	32 - 33	14 - 15
A115	121 - 162	18.33 - 32.02	60 - 61	27	32 - 33	14 - 15
A116	135 - 143	21 - 24.01	60 - 61	27	32	15
A117	121 - 146	18.55 - 24.47	60 - 61	26 - 27	32	14 - 15
A118	123 - 149	19.18 - 27.2	60 - 61	27	32 - 33	14 - 15
A119	136 - 151	22 - 27.06	60 - 61	27	32 - 33	15
A120	121 - 151	18.66 - 27.41	60 - 61	26 - 27	32 - 33	14 - 15
A121	120 - 139	17.36 - 22.31	60	26 - 27	32	14 - 15
A122	140 - 153	22.55 - 28.19	60 - 61	27	32 - 33	15
A123	140 - 152	22.37 - 27.33	60 - 61	27	32 - 33	15
A124	122 - 170	19.06 - 31.01	60 - 61	26 - 27	32 - 33	14 - 15
A125	136 - 162	22.05 - 33.31	61	27	32 - 33	15
A126	122 - 156	19.19 - 36.35	61 - 62	27 - 28	32 - 34	14 - 15
A127	121 - 150	18.67 - 27.95	60 - 61	27	32 - 33	14 - 15
A128	133 - 156	21.34 - 32.68	61 - 62	27	32 - 33	15
A129	170	33.64	61	27	33	15
A130	136 - 152	22.03 - 29.33	61	27	33	15
A131	136 - 162	21.84 - 33.25	61	27	33	15
A132	138 - 156	22.39 - 30.97	61	27	33	15
A133	143 - 169	23.95 - 35.26	61 - 62	27	33	15
A134	136 - 170	21.63 - 36.13	61 - 62	27	33	15
A135	138 - 163	22.64 - 34.15	61 - 62	27	33	15
A136	172	-	61	-	33	-
A137	137 - 163	22.49 - 33.98	61 - 62	27	33	15
A138	136 - 159	21.86 - 32.73	61 - 62	27	33	15
A139a	137 - 167	22.09 - 36.76	61 - 62	27	33	15
A139b	137 - 167	22.05 - 35.75	61	27	33	15
A140	138 - 167	22.21 - 34.83	61	27	33	15
A141	136 - 164	21.85 - 33.34	61	27	33	15
A142	135 - 174	20.9 - 41.52	61 - 62	27	33 - 34	15
A143	134 - 150	20.71 - 26.77	61	27	33	15
A144	136 - 176	22.32 - 32.13	61	27	33	15
A145	135 - 159	21.44 - 27.66	61	27	33	15
A146	135 - 165	21.86 - 31.35	61	27	33	15
A147	141 - 159	24.26 - 30.32	61	27	33	15
A148	170 - 173	35.97 - 36.83	62	27	33 - 34	15
A149	135 - 144	21.02 - 27.56	61	27	33	15
A150	133 - 139	20.57 - 22.83	61	26 - 27	33	15
A154	160	-	62	-	34	-
A155	138 - 160	23.11 - 36.02	61 - 62	27	33 - 34	15
A156	136 - 159	22.41 - 36.08	61 - 62	27	33 - 34	15
A157	138 - 155	23.5 - 34.15	61 - 62	27	33 - 34	15
A158	155	-	62	-	34	-
A159	146 - 155	25.92 - 31.35	61 - 62	27	33 - 34	15
A160	136 - 161	22.32 - 36.93	61 - 62	27	33 - 34	15
A161	136 - 155	22.33 - 31.21	61 - 62	27	33	15
A162	156 - 162	31.86 - 39.1	62 - 63	27 - 28	34	15 - 16
A163	149 - 153	25.52 - 32.45	61 - 62	27	33 - 34	15

Notes:

1. Exceedance of the relevant AQOs is bolded and underlined.

2. Long-term AQOs are not applicable to A7, A9, A25, A31, A42, A53, A54, A78, A136, A154, and A158 in consideration of short retention time at these kinds of uses.

3.7.2.3 According to Table 3.9, a total of 5 ASRs would exceed the AQO for the annual average NO₂ concentrations (i.e., 40 ug/m³). In order to investigate whether the project would induce any adverse impact, changes in annual average NO₂ concentrations between with Project (with DNR) and without Project scenarios for the ASRs with exceedance of AQOs are presented in Table 3.10. Detailed concentration changes in annual average NO₂ between with Project (with DNR) and without Project scenarios are presented in Appendix 3.15. The results indicate the reduction of the annual NO₂ concentration after the Project is in operation and noise mitigation measures are in place. The changes of these 5 ASRs are in the ranges of -1.38 to -0.08 ug/m³. As such, the Project would not induce an additional air quality impact on the ASRs.

Table 3.10 Difference in Predicted Annual-averaged NO₂ at Representative Air Sensitive Receivers under With Project (With DNR) Scenario and Without Project Scenario

ASR	Assessment Height Above Ground (mAG)	Annual-averaged NO2 (µg/m^3)
		With-Project (With DNR) Scenario	Without Project Scenario	Difference
A66a	5	40.20	41.26	-1.06
A71b	1.5	40.18	41.56	-1.38
A84	1.5	40.81	41.13	-0.32
A102	5	40.11	40.91	-0.80
A142	1.5	41.52	41.60	-0.08

3.7.2.4 According to the discrete results, the worst affect level would be 1.5 mAG and 5 mAG. None of the discrete ASRs above 5mAG exceeded the corresponding AQOs criteria. Contour plots of the 19^th highest hourly average and annual average NO₂ concentrations, the 10^th highest daily average and annual average RSP concentrations, and the 19^th highest daily average and annual average FSP concentrations at 1.5mAG and 5mAG under With Project (With DNR) Scenario are predicted and presented in Figure 3.7a, Figure 3.7b, Figure 3.8a, Figure 3.8b, Figure 3.9a, Figure 3.9b, Figure 3.10a, Figure 3.10b, Figure 3.11a, Figure 3.11b, Figure 3.12a, Figure 3.12b, Figure 3.13a, Figure 3.13b, Figure 3.14a, Figure 3.14b, Figure 3.15a, Figure 3.15b, Figure 3.16a, Figure 3.16b, Figure 3.17a, Figure 3.17b, Figure 3.18a and Figure 3.18b. Referring to the contour plots (Figure 3.7a, Figure 3.7b, Figure 3.8a, Figure 3.8b, Figure 3.9a, Figure 3.9b, Figure 3.10a, Figure 3.10b and Figure 3.13a, Figure 3.13b, Figure 3.14a, Figure 3.14b, Figure 3.15a, Figure 3.15b, Figure 3.16a, Figure 3.16b), no exceedance zone is found for the 10^th highest daily RSP, the 19^th highest daily FSP, and the annual averaged RSP and FSP concentrations at 1.5 mAG and 5 mAG. For the 19^th highest hourly NO₂, as shown in Figure 3.11a and Figure 3.11b, it can be seen that 7 exceedance zones at 1.5mAG are predicted at Hing Fong Road, Kwai Tsing Road, Tsuen Wan Road near Kerry Warehouse (Tsuen Wan), EW International Tower and Goodman Texaco Centre on Texaco Road. No air-sensitive uses were identified within these exceedance zones. Also, several small exceedance zones at 5mAG are found on Tsuen Wan Road near Wing Kei Road and Kwai Chung Park (shown in Figure 3.17b) but no air sensitive uses are found within these exceedance zones. Figure 3.12a, Figure 3.12b, Figure 3.18a and Figure 3.18b show that there is exceedance in the annual averaged NO₂ concentration at 1.5mAG and 5 mAG, where located in Tai Chung Road, Tai Ho Road, the junction of Yeung Uk Road and Ma Tau Pa Road, Tsing Tsuen Road, Texaco Road, Hing Fong Road, Kwai Fuk Road and Tsuen Wan Road (between Tsing Tsuen Road and Hing Fong Road. As to demonstrate that the air quality in the assessment area with AQO exceedance would not deteriorate during the operation period, annual averaged NO₂ concentrations at 1.5mAG and 5mAG under Without Project Scenario are also predicted and presented in Figure 3.19a, Figure 3.19b, Figure 3.20a and Figure 3.20b. Although there are some ASRs located within the exceedance zone at 1.5mAG and 5mAG, it shows an improvement in air quality impact under With Project (With DNR) Scenario. No ASRs located within the exceedance zone at 1.5mAG and 5mAG with additional annual average NO₂ impact is identified.

Incremental Air Quality Impact

3.7.2.5 By comparing the assessment result under “with project (with DNR)” and “without project” scenarios, the predicted incremental air quality impact is summarized in Table 3.11. Detailed results are presented in Appendix 3.15. According to the results shown in Table 3.11, the predicted cumulative concentrations under with Project (with DNR) scenario with maximum concentration changes were increased to different extents as compared to those under the without Project scenario. Nevertheless, the elevated concentrations would still comply with the corresponding AQOs.

Table 3.11 Summary of Incremental Air Quality Impact

Pollutant		AQO, ug/m^3	Predicted max. concentration changes, ug/m^3 ^[1]	Predicted cumulative conc. at the ASRs with max. concentration changes, ug/m^3
RSP	10^th Highest Daily Average	100	+0.33 (A64)	61
	Annual Average	50	+0.27 (A64)	28
FSP	19^th Highest Daily Average	50	+0.24 (A64)	33
	Annual Average	25	+0.25 (A64)	16
NO2	19^th Highest Hourly Average	200	+4.18 (A133)	169
	Annual Average	40	+2.25 (A64)	38

Note:

[1] ( ) refers to the representative ASRs with the maximum concentration changes.

Air Quality Implication due to the Recommended Direct Technical Noise Remedies (DNR)

3.7.2.6 In order to investigate the air quality implications induced by the proposed DNR, the predicted cumulative air quality impacts at the ASRs under With Project (Without DNR) scenario have been evaluated and the detailed assessment results are presented in Appendix 3.16. According to Appendix 3.16, the changes between with and without DNR are in the range of -9.20 to 9.25 ug/m³ for 19^th highest hourly NO₂, -2.95 to 3.53 ug/m³ for annual NO₂, -0.27 to 0.35 ug/m³ for 10^th highest daily RSP, -0.22 to 0.30 ug/m³ for annual RSP, -0.31 to 0.24 ug/m³ for 19^th highest daily FSP and -0.20 to 0.27 ug/m³ for annual FSP. For ASRs with exceedance of annual average NO₂ concentrations, their predicted NO₂ concentrations are reduced under with Project (with DNR) scenario as compared to those under with Project (without DNR) scenario. For other ASRs, the predicted air pollutant concentrations comply with the respective AQO limit values regardless of the concentration changes due to the implementation of DNR. Therefore, the proposed DNR would not result in any adverse or additional air quality impacts.

3.8 Mitigation of Adverse Environmental Impacts

3.8.1 Construction Phase

3.8.1.1 The approved NRMMs under NRMM Regulation (excluding exempted NRMMs) would be used on site and NRMMs supplied with mains electricity instead of diesel-powered should be adopted as far as possible to minimize the potential emission from NRMMs.

3.8.1.2 In addition, dust suppression measures stipulated in the Air Pollution Control (Construction Dust) Regulation and good site practices listed below should be carried out to further minimize construction dust impact.

· Use of regular watering to reduce dust emissions from exposed site surfaces and unpaved roads, particularly during dry weather.

· Use of frequent watering for particularly dusty construction areas and areas close to ASRs.

· Side enclosure and covering of any aggregate or dusty material storage piles to reduce emissions. Where this is not practicable owing to frequent usage, watering shall be applied to aggregate fines.

· Open stockpiles shall be avoided or covered. Where possible, prevent placing dusty material storage piles near ASRs.

· Tarpaulin covering of all dusty vehicle loads transported to, from and between site locations.

· Establishment and use of vehicle wheel and body washing facilities at the exit points of the site.

· Provision of wind shield and dust extraction units or similar dust mitigation measures at the loading area of barging point, and use of water sprinklers at the loading area where dust generation is likely during the loading process of loose material, particularly in dry seasons/ periods.

· Provision of not less than 2.4m high hoarding from ground level along site boundary where adjoins a road, streets or other accessible to the public except for a site entrance or exit.

· Imposition of speed controls for vehicles on site haul roads.

· Where possible, routing of vehicles and positioning of construction plant should be at the maximum possible distance from ASRs.

· Instigation of an environmental monitoring and auditing program to monitor the construction process in order to enforce controls and modify method of work if dusty conditions arise.

· Locate all the dusty activities away from any nearby ASRs as far as practicable.

· Erect higher hording at the location with ASRs in immediate proximity to the project site boundary.

· All malodorous materials shall be placed as far as possible from any ASRs.

· The stockpiled malodorous materials shall be covered entirely by plastic tarpaulin sheets.

· The malodorous materials shall be removed from site as soon as possible and shall not be stockpiled overnight at the site.

· Loading of the malodorous materials onto the dump trucks shall be controlled to avoid spillage.

3.8.1.3 With the implementation of the mitigation measures stipulated in the Air Pollution Control (Construction Dust) Regulation, unacceptable construction dust impact would not be anticipated.

3.8.2 Operation Phase

3.8.2.1 According to Table 3.10, there would be a decrease in annual average NO₂ concentration for the “With Project (with DNR)” scenario compared to the “Without Project” Scenario for the identified ASRs with exceedance of annual NO₂ AQO, no additional air quality impact would be anticipated during the operation phase.

3.8.2.2 The “Roadmap for the Popularization of Electric Vehicles in Hong Kong” (hereinafter referred to as “EV Roadmap”) proposes a series of measures to achieve zero vehicular emissions before 2050. The main measures of the EV Roadmap include ceasing the new registration of fuel-propelled and hybrid private cars by 2035 or earlier, promoting trials of electric public transport and commercial vehicles, and expanding the Electric Vehicles (EV) charging network in Hong Kong, etc. The use of electric private cars (e-PCs) has been considered to reduce vehicular emissions from private cars in this assessment (see Appendix 3.2 – Annex A). Apart from the emission from private cars, commercial vehicles, such as double-decker buses, single-decker buses, taxis, public light buses, and goods vehicles are the major sources of roadside air pollution. Using electric public transportation can reduce roadside air pollution, especially for this Project. Also, referring to Sections 3.7.2.3 - 3.7.2.4, the project would not cause adverse air quality impact on the ASRs with compliance of AQOs and additional air quality impacts on the ASRs with exceedance of AQOs. By implementing the measures in the “EV roadmap”, the air quality would be further improved.

3.9 Evaluation of Residual Impacts

3.9.1 Construction Phase

3.9.1.1 With the implementation of the mitigation measures as stipulated in the Air Pollution Control (Construction Dust) Regulation together with the recommended dust control measures and good site practices on the work sites, no adverse residual impact would be expected from construction of the Project.

3.9.2 Operation Phase

3.9.2.1 No adverse residual impact is expected during the operation phase of the Project.

3.10 Environmental Monitoring and Audit

3.10.1 Construction Phase

3.10.1.1 EM&A for potential dust impacts should be conducted during construction phase so as to check compliance with the legislative requirements. Details of the monitoring and audit programme are contained in a stand-alone EM&A Manual.

3.10.1.2 Regular site audits for potential dust impact are recommended to be conducted during the entire construction phase of the Project so as to ensure the dust mitigation measures and the dust suppression measures stipulated in Air Pollution Control (Construction Dust) Regulation are implemented in order.

3.10.2 Operation Phase

3.10.2.1 No adverse residual air quality impact arising from the Project is anticipated during the operation of the Project. Therefore, the EM&A works for the operation phase are considered unnecessary.

3.11 Conclusion

3.11.1 Construction Phase

3.11.1.1 The potential air quality impacts may arise from the construction works of the Project including site clearance, demolition of the existing structure and minor excavation with limited backfilling for column installation and wind erosion of limited exposed area. With the implementation of mitigation measures specified in the Air Pollution Control (Construction Dust) Regulation together with the recommended dust suppression measures, good site practices, and EM&A programme, no adverse dust impact at ASRs is anticipated due to the construction activities of the Project.

3.11.2 Operation Phase

3.11.2.1 Cumulative air quality impact arising from vehicular emission and start emission from the existing open road, emission associated with bus and minibus termini, HGV carparks, on-street minibus carparks, and PC carparks, industrial and marine emissions within 500m study area, and other major sources within 4km, has been assessed for the operation phase of the Project. The results concluded that the predicted cumulative air quality concentrations on the identified ASRs comply with the respective AQOs except for ASRs A66a, A71b, A84, A102, and A142. For these identified ASRs with exceedance of the AQO for the annual average NO₂ concentrations, there would be a decrease in annual average NO₂ concentration compared to the “Without Project” Scenario which indicated the Project would improve the environment from air quality aspect and no additional air quality impact would be generated due to the Project during the operation phase. In addition, the predicted 19^th highest hourly average NO₂, 10^th highest daily average, and annual average RSP and 19^th highest daily average and annual FSP concentrations at all representative ASRs would comply with the respective AQOs.

---

[1] The Executive Summary of “Study on the Strategic Development Plan for Hong Kong Port 2030” is available at https://www.hkmpb.gov.hk/document/ES_Eng.pdf.

[2] Environment Agency. 2007.Review of methods for NO to NO₂ conversion in plumes at short range. Prepared by Environmental Agency.

3 Jenkin. 2004a. Analysis of sources and partitioning of oxidant in the UK – Part 1: The NOx-dependence of annual mean concentrations of nitrogen dioxide and ozone. Atmospheric Environment, 38, 5117-5129.