Contents

3 Air Quality  1

3.1 Legislation, Standards and Guidelines  1

3.2 Description of the Environment 3

3.3 Air Sensitive Receivers  9

3.4 Construction Dust Assessment 14

3.5 Operational Air Quality Assessment 39

3.6 Air Quality Impact Assessment Conducted by SHO and SHD Replanning Works  87

3.7 Conclusion  88

3.8 References  88

Appendices

Appendix 3.1       Calculations of Dust Emission and Active Area

Appendix 3.1a     Routing of Construction Vehicles

Appendix 3.2       AERMET Surface Characteristic Parameters

Appendix 3.3       Hourly Composite Vehicular Emission Factor (for Construction Dust Assessment)

Appendix 3.4       Detailed Construction Dust Assessment Results (Unmitigated)

Appendix 3.5       Justification of Dust Suppression Efficiency

Appendix 3.6       Detailed Construction Dust Assessment Results (Mitigated)

Appendix 3.7       Traffic Forecast

Appendix 3.8       EMFAC-HK Key Model Assumptions

Appendix 3.9       Hourly Composite Vehicular Emission Factor (for Operational Air Quality Assessment)

Appendix 3.10 Details of Criteria Pollutant and Odourous Emission Inventory

Appendix 3.11 Detailed Operational Air Quality Assessment Results

Appendix 3.11a   Detailed Air Quality Assessment Results Extracted from SHO and SHD Replanning Works EIA

Appendix 3.11b Sensitivity Test on Contribution from TM-CLK Link

Appendix 3.12     Detailed Odour Assessment Results

Figures

Figure 3.1             Locations of Concerned PATH Grids

Figure 3.2 Location of Representative Air Sensitive Receivers

Figure 3.3 Construction Dust Impact Assessment Area

Figure 3.4a Contours of Cumulative Unmitigated Maximum 1-Hour TSP Concentration at 1.5m Above Ground (Construction Phase)

Figure 3.4b           Contours of Cumulative Unmitigated 10th Highest 24-Hour RSP Concentration at 1.5m Above Ground (Construction Phase)

Figure 3.4c Contours of Cumulative Unmitigated Annual RSP Concentration at 1.5m Above Ground (Construction Phase)

Figure 3.4d Contours of Cumulative Unmitigated 10th Highest 24-Hour FSP Concentration at 1.5m Above Ground (Construction Phase)

Figure 3.4e Contours of Cumulative Unmitigated Annual FSP Concentration at 1.5m Above Ground (Construction Phase)

Figure 3.4f Contours of Cumulative Unmitigated Maximum 1-Hour TSP Concentration at 13.6m Above Ground (Construction Phase)

Figure 3.4g           Contours of Cumulative Unmitigated 10th Highest 24-Hour RSP Concentration at 13.6m Above Ground (Construction Phase)

Figure 3.4h Contours of Cumulative Unmitigated Annual RSP Concentration at 13.6m Above Ground (Construction Phase)

Figure 3.4i Contours of Cumulative Unmitigated 10th Highest 24-Hour FSP Concentration at 13.6m Above Ground (Construction Phase)

Figure 3.4j Contours of Cumulative Unmitigated Annual FSP Concentration at 13.6m Above Ground (Construction Phase)

Figure 3.5a Contours of Cumulative Mitigated Maximum 1-Hour TSP Concentration at 1.5m Above Ground (Construction Phase )

Figure 3.5b Contours of Cumulative Mitigated 10th Highest 24-Hour RSP Concentration at 1.5m Above Ground (Construction Phase )

Figure 3.5c Contours of Cumulative Mitigated Annual RSP Concentration at 1.5m Above Ground (Construction Phase )

Figure 3.5d Contours of Cumulative Mitigated 10th Highest 24-Hour FSP Concentration at 1.5m Above Ground (Construction Phase )

Figure 3.5e Contours of Cumulative Mitigated Annual FSP Concentration at 1.5m Above Ground (Construction Phase )

Figure 3.5f Contours of Cumulative Mitigated Maximum 1-Hour TSP Concentration at 13.6m Above Ground (Construction Phase)

Figure 3.5g Contours of Cumulative Mitigated 10th Highest 24-Hour RSP Concentration at 13.6m Above Ground (Construction Phase)

Figure 3.5h Contours of Cumulative Mitigated Annual RSP Concentration at 13.6m Above Ground (Construction Phase)

Figure 3.5i Contours of Cumulative Mitigated 10th Highest 24-Hour FSP Concentration at 13.6m Above Ground (Construction Phase)

Figure 3.5j Contours of Cumulative Mitigated Annual FSP Concentration at 13.6m Above Ground (Construction Phase)

Figure 3.6             Not Used

Figure 3.7 Operational Air Quality Assessment Area

Figure 3.8 Locations of Potential Emission Sources

Figure 3.9a Contours of Cumulative 19th Highest 1-Hour NO₂ Concentration at 1.5m Above Ground (Operational Phase)

Figure 3.9b Contours of Cumulative Annual NO₂ Concentration at 1.5m Above Ground (Operational Phase)

Figure 3.10a Contours of Cumulative 10th Highest 24-Hour RSP Concentration at 1.5m Above Ground (Operational Phase)

Figure 3.10b Contours of Cumulative Annual RSP Concentration at 1.5m Above Ground (Operational Phase)

Figure 3.11a Contours of Cumulative 10th Highest 24-Hour FSP Concentration at 1.5m Above Ground (Operational Phase)

Figure 3.11b Contours of Cumulative Annual FSP Concentration at 1.5m Above Ground (Operational Phase)

Figure 3.12a Contours of Cumulative 19th Highest 1-Hour NO₂ Concentration at 13.6m Above Ground (Operational Phase)

Figure 3.12b Contours of Cumulative Annual NO₂ Concentration at 13.6m Above Ground (Operational Phase)

Figure 3.13a Contours of Cumulative 10th Highest 24-Hour RSP Concentration at 13.6m Above Ground (Operational Phase)

Figure 3.13b Contours of Cumulative Annual RSP Concentration at 13.6m Above Ground (Operational Phase)

Figure 3.14a Contours of Cumulative 10th Highest 24-Hour FSP Concentration at 13.6m Above Ground (Operational Phase)

Figure 3.14b Contours of Cumulative Annual FSP Concentration at 13.6m Above Ground (Operational Phase)

Figure 3.15a Contours of Cumulative 5-Second Maximum Odour Concentration at 5 m Above Ground

Figure 3.15b Contours of Cumulative 5-Second Maximum Odour Concentration at 10 m Above Ground

Figure 3.15c Contours of Cumulative 5-Second Maximum Odour Concentration at 13.6 m Above Ground

Figure 3.15d Contours of Cumulative 5-Second Maximum Odour Concentration at 50 m Above Ground

3 Air Quality

3.1 Legislation, Standards and Guidelines

3.1.1 General

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

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

· Air Pollution Control (Construction Dust) Regulation;

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

· EIAO (Cap. 499), Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM), Annex 4 and Annex 12.

3.1.1.2 The APCO (Cap.311) provides the power for controlling air pollutants from a variety of stationary and mobile sources and encompasses a number of Air Quality Objectives (AQOs).

3.1.2 Air Quality Objectives

3.1.2.1 The air quality impact assessment criteria shall make reference to the Hong Kong Planning Standards and Guidelines (HKPSG), the APCO (Cap.311), and Annex 4 of the EIAO-TM.

3.1.2.2 The APCO (Cap.311) provides the power for controlling air pollutants from a variety of stationary and mobile sources and encompasses a number of AQOs. In addition to the APCO, the following overall policy objectives are laid down in Chapter 9 of the HKPSG as follows:

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

· Ensure that the AQOs for seven common air pollutants are met as soon as possible.

3.1.2.3 Currently, the AQOs stipulate limits on concentrations for seven pollutants including sulphur dioxide (SO2), Respirable Suspended Particulates (RSP), Fine Suspended Particulates (FSP), Nitrogen Dioxide (NO₂), Carbon Monoxide (CO), photochemical oxidants, and Lead (Pb).  The prevailing AQOs are listed in Table 3.1 below.

Table 3.1 Hong Kong Air Quality Objectives (AQOs)

Pollutant	Limits on Concentration, µg/m^3 ^[1] (Number of exceedances allowed per year in brackets)
	10-min	1-hr	8-hr	24-hr ^[2]	Annual ^[2]
Sulphur Dioxide (SO2)	500 (3)			125 (3)
Respirable Suspended Particulates (RSP) ^[3]				100 (9)	50 (0)
Fine Suspended Particulates (FSP) ^[4]				75 (9)	35 (0)
Carbon Monoxide (CO)		30,000 (0)	10,000 (0)
Nitrogen Dioxide (NO2)		200 (18)			40 (0)
Ozone (O3)			160 (9)
Lead (Pb)					0.5 (0)

Notes:

[1]   Measured at 293K and 101.325kPa.

[2]   Arithmetic mean.

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

[4]   Fine suspended particulates means suspended particulates in air with a nominal aerodynamic diameter of 2.5 micrometres or smaller.

3.1.3 Air Pollution Control (Construction Dust) Regulation

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

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

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

3.1.5 Total Suspended Particulate Criteria

3.1.5.1 There is no criterion on Total Suspended Particulate (TSP) under the AQO. In accordance with Annex 4 of EIAO-TM, a limit of 500μg/m³ for 1-hour TSP concentration at any sensitive receivers should be adopted for evaluating air quality impacts.

3.1.6 Odour Criterion

3.1.6.1 In accordance with Annex 4 of EIAO-TM, the limit of 5 odour units based on an averaging time of 5 seconds for odour prediction assessment should not be exceeded at any receivers.

3.1.7 Practice Note on Control of Air Pollution in Semi Confined Public Transport Interchanges

3.1.7.1 The Practice Note on Control of Air Pollution in Semi-Confined Public Transport Interchanges (ProPECC PN 1/98) specifies guidelines on air quality within public transport interchanges (PTIs), the design of PTIs (including the layout and ventilation system) and operation procedures.

3.2 Description of the Environment

3.2.1 Existing Ambient Air Quality Conditions

3.2.1.1 There is no Air Quality Monitoring Station (AQMS) within the assessment area. The nearest AQMS operated by EPD to the assessment area is located at Tung Chung. The average air quality monitoring data at Tung Chung from the past 5 years (i.e. 2012 – 2016) has been reviewed and is summarised in Table 3.2 below.

Table 3.2 Air quality monitoring data against prevailing AQO (Tung Chung Station, 2012-2016)

Pollutant	Parameter	Concentration (µg/m^3)
		2012	2013	2014	2015	2016	5-year Average	AQO (No. of Exceedances allowed)
SO2	4^th highest 10-minute	N/A	N/A	86	88	63	79 [16%]	500 (3)
	4^th highest 24-hour	33	39	35	22	20	30 [24%]	125 (3)
NO2	19^th highest 1-hour	166	177	198	162	150	171 [86%]	200 (18)
	Annual	43	49	45	40	36	43 [107%]	40 (0)
CO	Highest 1-hour	2660	1810	2230	1780	2260	2148 [7%]	30,000 (0)
	Highest 8-hour	2461	1640	1692	1416	1581	1758 [18%]	10,000 (0)
O3	10^th highest 8-hour	197	171	175	176	142	172 [108%]	160 (9)
RSP	10^th highest 24-hour	106	108	101	93	92	100 [100%]	100 (9)
	Annual	45	42	39	36	33	39 [78%]	50 (0)
FSP	10^th highest 24-hour	74	76	65	65	63	69 [92%]	75 (9)
	Annual	28	26	24	22	21	24 [69%]	35 (0)

Note:

[1]    N/M – Not Measured; N/A - Not applicable since there is no AQO for this parameter.

[2]    Number of exceedance allowed under the AQO is shown in ( ), % of the AQO is shown in [ ].

[3]    Monitoring results exceeding the AQO are bolded. 

[4]    Only monitoring data based on the AQO of 10-min SO₂ for 2014 and 2015 is publicly available.

3.2.1.2 The 4^th highest 10-minute and the 4th highest daily SO₂ levels were well within the corresponding AQOs.

3.2.1.3 The 19th highest 1-hour NO₂ levels were ranged from 150 to 198μg/m³, which were within the AQO of 200μg/m³. The annual NO₂ level exhibited a downward trend, decreased from 49μg/m³ in 2013 to within the AQO of 40μg/m³ in 2016.

3.2.1.4 The highest 1-hour and 8-hour CO levels were also well within the corresponding AQOs.

3.2.1.5 The highest 8-hour O₃ levels were ranged from 142 to 197μg/m³, with an average level of 172 μg/m³ which exceeds the AQO by about 8%.

3.2.1.6 The 10th highest daily RSP levels had decreased from 108μg/m³ in 2013 to 92μg/m³ in 2016, as compared with the AQO of 100μg/m³. The annual RSP levels also exhibited a downward trend from 45μg/m³ in 2012 to 33μg/m³ in 2016, which were all within the AQO of 50μg/m³.

3.2.1.7 The 10th highest daily FSP levels were within the AQO of 75μg/m³ in the past 5 years except Year 2013 (i.e. 76μg/m³). The annual FSP level also exhibited a downward trend, decreased from 28μg/m³ in 2012 to 21μg/m³ in 2016 which were all within the AQO of 35μg/m³.

3.2.2 Future Ambient Air Quality Condition

3.2.2.1 The future ambient air quality is influenced by various sources in Hong Kong including territory wide vehicular emission, power plants and marine emission, the Hong Kong International Airport, as well as regional emission from Pearl River Delta (PRD), etc.

3.2.2.2 In 2002, the HKSAR jointly agreed regional air emission reduction targets to be achieved by 2010 with the Guangdong Provincial Government. The figures for the Year 2010 (Table 3.3) show that emissions of SO₂, NO_x, RSP and Volatile Organic Compounds (VOCs) have been reduced beyond the agreed targets. This is a result of setting caps on emissions from power plants (under the First Technical Memorandum (December 2008) and the power companies retrofitting their coal fired generation units with air pollution reduction equipment), introduction of cleaner motor vehicle fuels and motor vehicles in Hong Kong and the Pearl River Delta (PRD), and phasing out highly polluting industrial plants in the PRD.

Table 3.3 Progress in achieving the 2010 emissions reduction targets

Pollutant	Emission Level 1997 (tonnes)	Emission Level 2010 (tonnes)	Change in Emission Level 1997-2010	Emission Reduction Target for 2010
SO2	82,000	35,500	-57%	-40%
NOX	154,000	108,600	-29%	-20%
RSP	15,500	6,340	-59%	-55%
VOC	81,700	33,700	-59%	-55%

Note:

[1]     Referenced from “Air Pollutant Emission Reduction Plan up to 2020”, ACE Briefing Paper 12/2012 (http://www.epd.gov.hk/epd/english/boards/advisory_council/files/ACE_Paper_12_2012.pdf).

3.2.2.3 In 2007, EPD had also commissioned a comprehensive study to review Hong Kong's AQOs and develop a long-term air quality management strategy.  The study has identified a host of comprehensive emission reduction measures for improving Hong Kong’s air quality, including:

· capping the emissions from power plants;

· advancing the earlier replacement of more polluting vehicles;

· promoting the use of more environmentally-friendly vehicles;

· further tightening the control of emissions from vessels and other sources;

· introducing suitable traffic management measures to reduce roadside emissions (such as low emission zones, etc.); and

· expanding rail/tram network, promoting energy efficiency.

3.2.2.4 Together with the joint effort of the Guangdong Provincial Government, the regional emission is expected to be further reduced and the background air quality impacts would be much improved in the near future.

3.2.2.5 During the 12th Hong Kong-Guangdong Joint Working Group Meeting on Sustainable Development and Environmental Protection (Nov 2012), the Hong Kong and Guangdong Governments jointly endorsed a Major Air Pollutant Emission Reduction Plan for the Pearl River Delta Region up to year 2020. Key emission reduction measures to be implemented by Hong Kong and Pearl River Delta Economic Zone (PRDEZ) include:

Hong Kong Government

· tightening of vehicle emission standards;

· phasing out highly polluting commercial diesel vehicles;

· retrofitting Euro II and Euro III franchised buses with selective catalytic reduction devices;

· strengthening inspection and maintenance of petrol and liquefied petroleum gas vehicles;

· requiring ocean-going vessels to switch to using low sulphur fuel while at berth;

· tightening the permissible sulphur content level of locally supplied marine diesel;

· controlling emissions from off-road vehicles/equipment;

· further tightening of emission caps on power plants and increasing use of clean energy for electricity generation; and

· controlling VOC contents of solvents used in printing and construction industry.

Pearl River Delta Economic Zone

· requiring thermal power plants to install low-NOx and denitrification systems;

· promoting conversion of oil-fired generating units into gas generating units;

· enhancing RSP emission control at power plants;

· promoting the use of National IV standard motor fuels (including petrol and diesel) and tightening diesel vehicle emission standards;

· phasing out yellow-label vehicles (i.e. petrol vehicles of pre-National emission standard or below and diesel vehicles of National II emission standard or below);

· phasing out highly polluting industries with low energy efficiency;

· enhancing emission control on industrial boilers as well as for specific industries (including petrochemical, cement, ceramic, furniture manufacturing, printing, etc.); and

· setting up a registration and reporting system on the usage and emission control of organic solvents at major enterprises with a view to strengthening VOC emission control

3.2.2.6 The two governments endorsed the emission reduction targets for Year 2015, and agreed to set emission reduction ranges for Year 2020. The reduction targets for the four major air pollutants in Hong Kong and PRDEZ for Year 2015 and Year 2020 are shown in Table 3.4 and Table 3.5 respectively.

Table 3.4 Summary of emission reduction targets in Hong Kong

Year	Pollutants (Thousand Tonnes)				References
	SO2	NOx	RSP	VOC
2010	35.5	108.6	6.34	33.7	The Hong Kong-Guangdong Joint Working Group on Sustainable Development and Environmental Protection (JWGSDEP) 12th meeting, 2012
2015	26.6	97.7	5.71	32.0
2020	23.1	86.9	5.39	28.6

Note:

[1]       Referenced from “Air Pollutant Emission Reduction Plan up to 2020”, ACE Briefing Paper 12/2012 (http://www.epd.gov.hk/epd/english/boards/advisory_council/files/ACE_Paper_12_2012.pdf)

Table 3.5 Summary of emission reduction targets in PRDEZ

Year	Pollutants (Thousand Tonnes)				References
	SO2	NOx	RSP	VOC
2010	507	889	637	903	The Hong Kong-Guangdong Joint Working Group on Sustainable Development and Environmental Protection (JWGSDEP) 12th meeting, 2012
2015	426	729	573	813
2020	406	711	541	768

Note:

[1]       Referenced from “Air Pollutant Emission Reduction Plan up to 2020”, ACE Briefing Paper 12/2012 (http://www.epd.gov.hk/epd/english/boards/advisory_council/files/ACE_Paper_12_2012.pdf)

3.2.2.7 The future ambient air quality (i.e. Year 2020) within the study boundary has been predicted by the Pollutants in the Atmosphere and the Transport over Hong Kong (PATH, a regional air quality prediction model developed by EPD) in this study. The committed and planned control measures to be implemented by the Hong Kong Government and PRDEZ outlined above are accounted for in PATH, which was last updated in January 2016. The 500m assessment area involves 9 grids in the PATH (as shown in Figure 3.1). The future ambient air quality within each PATH grid, based on the most up-to-date results from EPD (January 2016), is summarized in the table below.

Table 3.6 Future ambient air quality in PATH grids within the assessment area in Year 2020

Pollutant	Parameter	20_31	20_32	21_31	21_32	21_33	22_32	22_33	23_32	23_33	AQO (No. of Exceedances allowed)
SO2	4^th highest 10-minute	114	125	107	106	115	107	112	109	112	500 (3)
	4^th highest 24-hour	29	30	29	30	31	30	31	30	31	125 (3)
NO2	19^th highest 1-hour	96	97	94	96	104	98	103	98	104	200 (18)
	Annual	18	18	17	18	20	18	20	18	20	40 (0)
CO	Highest 1-hour	1004	1006	1002	1008	1009	1005	1008	999	1004	30,000 (0)
	Highest 8-hour	822	823	825	828	830	828	831	832	840	10,000 (0)
O3	10^th highest 8-hour	159	159	159	160	160	154	155	158	157	160 (9)
RSP	10^th highest 24-hour	77	79	77	77	80	79	77	80	79	100 (9)
	Annual	33	33	33	32	33	34	33	34	34	50 (0)
FSP	10^th highest 24-hour	58	59	58	58	60	59	58	60	59	75 (9)
	Annual	23	23	23	23	24	24	23	24	24	35 (0)

Notes:

[1]       Values are given as highest 10-minute SO₂ concentrations, which are estimated based on EPD’s “Guidelines on the Estimation of 10-minute Average SO₂ Concentration for Air Quality Assessment in Hong Kong”.

[2]        Values in ( ) indicate number of exceedance allowed under the AQO.

[3]       In accordance to EPD’s “Guidelines on Choice of Models and Model Parameters” (dated September 2016), 26.5 μg/m³ and 15.6 μg/m³ are added to PATH data in determination of 10th highest daily and the annual RSP concentrations respectively.

[4]        FSP concentrations are estimated in accordance with EPD’s “Guidelines on the Estimation of FSP for Air Quality Assessment in Hong Kong”.

3.2.2.8 It can be seen from the above table that, with the implementation of the emission reduction measures by both the Hong Kong and Guangdong Governments, future background air quality in Year 2020 would be significantly improved. Concentrations of all criteria pollutants comply with AQO. In particular, the annual background NO₂ concentration in the assessment area would be significantly reduced to 17 – 20μg/m³ in Year 2020.

3.2.2.9 The O₃ level, which is a regional air pollutant, is also expected to be complied with the AQO. This would be achieved through implementing measures, as agreed by the Hong Kong and Guangdong Governments, to control emission of O₃ precursors such as NO_x and VOC.

3.3 Air Sensitive Receivers

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

3.3.1.2 With reference to Clause 3.4.4.2 of the EIA Study Brief, the assessment area for air quality impact assessment should be defined by a distance of 500m from boundary of the Project and the works of the Project within the Study Area, including eastern connection access on Sham Shui Kok Drive, western access via Tai Ho Interchange, and construction of pumping station and associated utilities. The assessment area is shown in Figure 3.2.

3.3.1.3 Representative ASRs within a distance of 500m from the Project area have been identified. These ASRs include both the existing and planned developments (i.e. proposed development under the Project). Existing ASRs are identified by means of reviewing topographic maps, aerial photos, land status plans, supplemented by site inspections. They include the Discovery Bay Tunnel Administration Building and Siu Ho Wan Government Maintenance Depot.

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

· Approved Tung Chung Extension Area Outline Zoning Plan (No. S/I-TCE/2); and

· Draft Tai Ho Outline Zoning Plan (NO.S/I-TH/1).

3.3.1.5 As stated in the above plans, the land uses within 500m from the boundary of the Project are mainly Agriculture, Green Belt, Country Park and Government/Institution/Community.

3.3.1.6 It is understood the population intake for the possible developments may be implemented in phases. Hence, developments in earlier stage will also be considered as ASRs where appropriate for assessment of the construction dust impact due to the subsequent development phases.  These ASRs will be identified based on the latest layout. As discussed in Section 3.4.4, the construction period for this Project will be 2023-2025 and 2036-2038. Thus construction dust impact on air quality will be evaluated for both existing and planned ASRs.

3.3.1.7 The locations of the representative ASRs are illustrated in Figure 3.2 and summarized in Table 3.7 below.

Table 3.7 Representative ASRs

ASR ID	Description	Land Use^[1]	Number of Storeys	Approximate Distance from Closest Emission Source (m) ^[2]
Existing ASRs
A1	Discovery Bay Tunnel Administration Building	C	2	80 (Construction) 40 (Operational) 160 (Odour)
A2	Siu Ho Wan Government Maintenance Depot	GIC	3	150 (Construction) 20 (Operational) 190 (Odour)
A3	Siu Ho Wan Sewage Treatment Works Administration Building	GIC	2	30 (Construction) 100 (Operational) 90 (Odour)
A4	Siu Ho Wan Water Treatment Works Administration Building	GIC	2	240 (Construction) 180 (Operational) 200 (Odour)
A5	Organic Waste Treatment Facilities Main Building	GIC	N/A	170 (Construction) 40 (Operational) 40 (Odour)
A6	North Lantau Refuse Transfer Station  Office	GIC	3	90 (Construction) 80 (Operational) 50 (Odour)
Planned ASRs
A101	Proposed development atop Siu Ho Wan Depot (Phase 1a)	R	17	450 (Construction) 50 (Operational) 1060 (Odour)
A104	Proposed development atop Siu Ho Wan Depot (Phase 1a)	R	18	520 (Construction) 40 (Operational) 990 (Odour)
A107	Proposed development atop Siu Ho Wan Depot (Phase 1a)	R	18	580 (Construction) 50 (Operational) 930 (Odour)
A108	Proposed development atop Siu Ho Wan Depot (Phase 1a)	R	18	620 (Construction) 50 (Operational) 890 (Odour)
A113	Proposed development atop Siu Ho Wan Depot (Phase 1a)	R	18	740 (Construction) 40 (Operational) 780 (Odour)
A115	Proposed development atop Siu Ho Wan Depot (Phase 1a)	R	18	730 (Construction) 40 (Operational) 730 (Odour)
A118	Proposed development atop Siu Ho Wan Depot (Phase 1a)	R	19	660 (Construction) 50 (Operational) 660 (Odour)
A125	Proposed development atop Siu Ho Wan Depot (Phase 1b)	R	16	150 (Construction) 50 (Operational) 1370 (Odour)
A128	Proposed development atop Siu Ho Wan Depot (Phase 1b)	R	16	230 (Construction) 40 (Operational) 1290 (Odour)
A131	Proposed development atop Siu Ho Wan Depot (Phase 1b)	R	17	300 (Construction) 40 (Operational) 1220 (Odour)
A135	Proposed development atop Siu Ho Wan Depot (Phase 1b)	R	17	380 (Construction) 50 (Operational) 1130 (Odour)
A136	Proposed development atop Siu Ho Wan Depot (Phase 1c)	R	19	620 (Construction) 50 (Operational) 620 (Odour)
A139	Proposed development atop Siu Ho Wan Depot (Phase 1c)	R	19	560 (Construction) 40 (Operational) 560 (Odour)
A142	Proposed development atop Siu Ho Wan Depot (Phase 1c)	R	20	490 (Construction) 60 (Operational) 490 (Odour)
A143	Proposed development atop Siu Ho Wan Depot (Phase 1c)	R	20	410 (Construction) 40 (Operational) 410 (Odour)
A146	Proposed development atop Siu Ho Wan Depot (Phase 1c)	R	20	350 (Construction) 30 (Operational) 350 (Odour)
A149	Proposed development atop Siu Ho Wan Depot (Phase 1c)	R	21	280 (Construction) 40 (Operational) 280 (Odour)
A209	Proposed development atop Siu Ho Wan Depot (Phase 2a)	R	18	370 (Construction) 220 (Operational) 1180 (Odour)
A211	Proposed development atop Siu Ho Wan Depot (Phase 2b)	R	17	400 (Construction) 130 (Operational) 1120 (Odour)
A212	Proposed development atop Siu Ho Wan Depot (Phase 2b)	R	17	500 (Construction) 100 (Operational) 1020 (Odour)
A215	Proposed development atop Siu Ho Wan Depot (Phase 2b)	R	17	600 (Construction) 180 (Operational) 930 (Odour)
A219	Proposed development atop Siu Ho Wan Depot (Phase 2b)	R	19	530 (Construction) 220 (Operational) 1020 (Odour)
A303	Proposed development atop Siu Ho Wan Depot (Phase 3a)	R	19	670 (Construction) 120 (Operational) 670 (Odour)
A307	Proposed development atop Siu Ho Wan Depot (Phase 3a)	R	19	540 (Construction) 100 (Operational) 540 (Odour)
A308	Proposed development atop Siu Ho Wan Depot (Phase 3a)	R	21	560 (Construction) 200 (Operational) 560 (Odour)
A310	Proposed development atop Siu Ho Wan Depot (Phase 3b)	R	18	630 (Construction) 120 (Operational) 890 (Odour)
A313	Proposed development atop Siu Ho Wan Depot (Phase 3b)	R	20	660 (Construction) 210 (Operational) 880 (Odour)
A318	Proposed development atop Siu Ho Wan Depot (Phase 3b)	R	20	700 (Construction) 210 (Operational) 700 (Odour)
A402	Proposed development atop Siu Ho Wan Depot (Phase 4a)	R	23	220 (Construction) 30 (Operational) 230 (Odour)
A404	Proposed development atop Siu Ho Wan Depot (Phase 4a)	R	23	160 (Construction) 30 (Operational) 170 (Odour)
A407	Proposed development atop Siu Ho Wan Depot (Phase 4a)	R	23	90 (Construction) 30 (Operational) 100 (Odour)
A409	Proposed development atop Siu Ho Wan Depot (Phase 4b)	R	22	400 (Construction) 110 (Operational) 400 (Odour)
A412	Proposed development atop Siu Ho Wan Depot (Phase 4b)	R	24	400 (Construction) 200 (Operational) 400 (Odour)
A414	Proposed development atop Siu Ho Wan Depot (Phase 4b)	R	20	340 (Construction) 80 (Operational) 340 (Odour)
A417	Proposed development atop Siu Ho Wan Depot (Phase 4c)	R	25	260 (Construction) 130 (Operational) 260 (Odour)
A419	Proposed development atop Siu Ho Wan Depot (Phase 4c)	R	25	170 (Construction) 90 (Operational) 170 (Odour)
A422	Proposed development atop Siu Ho Wan Depot (Phase 4c)	R	26	80 (Construction) 70 (Operational) 70 (Odour)
A501	Proposed development atop Siu Ho Wan Depot (Phase 2a)	E	7	250 (Construction) 90 (Operational) 1270 (Odour)
A601	Proposed development atop Siu Ho Wan Depot (Phase 3b)	E	7	690 (Construction) 80 (Operational) 820 (Odour)
A701	Proposed development atop Siu Ho Wan Depot (Phase 4c)	E	7	240 (Construction) 60 (Operational) 240 (Odour)

Notes:

[1]  C – Commercial; GIC – Government, institution and community; R – Residential; E – Education

[2]  The distance for construction phase refers to the distance from the closest works area considered in the construction dust assessment associated with the Project. The distance for operational phase refers to the distance to the closest road, chimney or marine source. The distance for odour refers to the distance from closest odour source including existing and planned source.

3.4 Construction Dust Assessment

3.4.1 Assessment Area

3.4.1.1 As discussed in Section 3.3, the assessment area for air quality impact assessment should be defined by a distance of 500m from boundary of the Project Area and the works of the Project within the Study Area. Figure 3.3 illustrates the extent of the study area for construction dust assessment.

3.4.2 Identification of Pollution Sources and Emission Inventory

Pollution Sources

3.4.2.1 According to the latest implementation strategy, site clearance, construction of concrete slab for podium deck of Stage 1 to 4, foundation of podium deck, SHD replanning works, SHO Station and associated trackworks as well as local access roads and emergency vehicular access would be implemented by the SHO and SHD Replanning Works and the associated impacts will be addressed in the Railway EIA.

3.4.2.2 Superstructures works for proposed SHD Topside Development for Stage 1 to 4 would be constructed under this Project. Construction of superstructures works will be carried out with insignificant construction dust emission.

3.4.2.3 Construction activities taken into account in this EIA include construction of access road to Tai Ho Interchange, sewage pumping station (SPS) and associated utilities connecting to existing Siu Ho Wan Sewage Treatment Works, and road widening works along Sham Shui Kok Drive. Construction dust (i.e. TSP, RSP and FSP) as the representative pollutants, will be potentially generated mainly from the at-grade construction works including the following activities: 

· Foundation works for SPS;

· Utility construction; and

· Road Widening.

3.4.2.4 In addition, dust emissions from existing and future sources (e.g. OWTF Phase 1) and the construction work for SHO and SHD Replanning Works would also have potential dust impact on ASRs and the cumulative impact is assessed.

Dust Emission associated with the Concurrent Projects / Dust Sources

3.4.2.5 For any concurrent projects with overlapping construction works, such as those shown in Table 3.8, the associated dust emission sources and emission strength are referenced to their respectively approved EIA Studies and/or the best available information.

Table 3.8 Key concurrent projects for construction dust assessment

Concurrent Project^[1]	Commissioning Year	Approximate Distance
Tung Chung New Town Extension^[2]	2023 – 2030	1.3 km
Hong Kong Zhuhai-Macau Bridge (HZMB) Hong Kong Boundary Crossing Facilities (HKBCF)^[3][9]	2017	2.5 km
Topside Development at HKBCF^[4][9]	Subject to confirmation	2.5 km
Expansion of Hong Kong International Airport into a Three-Runway System^[5][9]	2023	4.5 km
Development of North Commercial District on Airport Island^[9]	First phase of NCD is targeted for completion in 2021	3.9 km
Tuen Mun-Chek Lap Kok Link (TM-CLK Link)^[6]	2020 at the earliest (Northern Section) 1^st Half of 2019 at the earliest (Southern Section)	2.8 km (Northern Section) In the vicinity (Southern Section)
Hong Kong Zhuhai-Macau Bridge (HZMB) Hong Kong Link Road (HKLR)^[7][9]	2017	3.7 km
Addition Sewage Rising Main and Rehabilitation of the Existing Sewage Rising Main between Tung Chung and Siu Ho Wan ^[8]	2025	In the vicinity

Notes:

[1]    As advised by CEDD, Siu Ho Wan (SHW) Reclamation and Road P1 (SHW Section) are in feasibility stage and has no implementation programme, thus not considered as concurrent project.

[2]    As per Tung Chung New Town Extension EIA (AEIAR-196/2016) (http://www.epd.gov.hk/eia/register/report/eiareport/eia_2332015/html/EIA/Text/General/Combined_html%20version.htm), the development would start in 2017 and would be completed by 2030. Tung Chung Extension phases 1 to 4 would be approximately 1.3 km away from site boundary of this Project. No significant impact would be anticipated. The Road P1 (Tung Chung – Tai Ho Section) and Tai Ho Interchange would be near but it is anticipated that the road will be completed by 2024 and before the first population intake of the Project in 2026. Cumulative impact on vehicular emissions will be incorporated. In addition, the Sewerage Network proposed will be completed between 2024 and 2027. Construction dust impact from such work is not anticipated due to the small scale of construction works.

[3]    Hong Kong - Zhuhai - Macao Bridge Hong Kong Boundary Crossing Facilities EIA (AEIAR-145/2009) (http://www.epd.gov.hk/eia/register/report/eiareport/eia_1732009/Contents%20Page.htm). The construction of the development will be completed before construction phase of this Project.

[4]    Planning, Engineering and Architectural Study for Topside Development of Hong Kong Boundary Crossing Facilities of Hong Kong-Zhuhai-Macao Bridge Study Brief (ESB-290/2015) (http://www.epd.gov.hk/eia/register/study/latest/esb-290.pdf). The commissioning year of this project is still subject to confirmation.

[5]    Expansion of Hong Kong International Airport into a Three-Runway System EIA (AEIAR-185/2014) (http://www.epd.gov.hk/eia/register/report/eiareport/eia_2232014/html/Master%20Content%20v1.htm) This project will be completed by 2023 before the first population intake in 2026.

[6]    Tuen Mun - Chek Lap Kok Link EIA (AEIAR-146/2009) (http://www.epd.gov.hk/eia/register/report/eiareport/eia_1742009/html/EIA%20Table%20of%20Contents.htm). According to latest information from HyD (http://tm-clkl-c1.hk/hy201207web/eng/introduction.html), the commissioning year of the Southern Section is 1^st Half of 2019 at the earliest. Cumulative impact from induced traffic will be incorporated.

[7]    Hong Kong - Zhuhai - Macao Bridge Hong Kong Link Road EIA (AEIAR-144/2009) (http://www.epd.gov.hk/eia/register/report/eiareport/eia_1722009/Contents%20Page.htm). The construction of the development will be completed before construction phase of this Project. Nevertheless, cumulative impact from induced traffic will be incorporated.

 [8]   Drainage Services Department, Projects (http://www.dsd.gov.hk/EN/Our_Projects/All_Projects/4381DS.html). This project will be completed by 2025 before the first population intake in 2026.

[9]    These projects are over 1 km away. Except induced traffic flow and the associated air emissions, it is anticipated that other cumulative impacts would not be significant given the distance. The induced traffic flow would be taken into account in the assessment for assessments.

3.4.2.6 It can be seen from the above table that the construction of some of the key concurrent project would have been completed before construction phase of this Project, except the following:

· Tung Chung New Town Extension;

· Development of North Commercial District on Airport Island;

· SHD Replanning Works and SHO Station; and

· Addition Sewage Rising Main and Rehabilitation of the Existing Sewage Rising Main between Tung Chung and Siu Ho Wan.

3.4.2.7 With reference to the approved EIA for Tung Chung New Town Extension (AEIAR-196/2016), construction works associated with  Tung Chung New Town Extension during the construction phase of the Project (2023-2025) are located >1.5km away from the Project boundary. Given the large separation distance between the construction site of this concurrent project and the Project, adverse cumulative dust impact from the construction activities of this concurrent project during construction phase of the Project is therefore not anticipated.

3.4.2.8 The HKBCF, Topside Development at HKBCF, Development of North Commercial District on Airport Island and HKLR are located >2km away from the Project boundary. Given the large separation distance between the construction site of above concurrent projects and the Project, adverse cumulative dust impact from the construction activities of these concurrent projects during construction phase of the Project is therefore not anticipated.

3.4.2.9 It is anticipated that there only very small scale of work would be involved for the construction / upgrading of Addition Sewage Rising Main and Rehabilitation of the Existing Sewage Rising Main between Tung Chung and Siu Ho Wan, adverse cumulative construction dust impact from such work is therefore not anticipated.

3.4.3 Key Representative Pollutants

3.4.3.1 According to Section 13.2.4.3 of USEPA AP-42, most of the particles in fugitive dust have an aerodynamic diameter of <30 μm and 47% of particles have an aerodynamic diameter of <10 μm. Hence, it is appropriate to adopt Total Suspended Particulates (TSP) (with aerodynamic diameter ≦30 μm) and Respirable Suspended Particulates (RSP) (with aerodynamic diameter ≦10 μm) as the representative pollutant for construction phase. As a conservative approach, FSP will also be assessed under the construction dust assessment, notwithstanding that it only constitutes 7% of the total particles in fugitive dust.

3.4.3.2 Fuel combustion from the use of Powered Mechanical Equipment (PME) during construction works could be a source of Nitrogen Dioxide (NO₂), Sulphur Dioxide (SO₂) and Carbon Monoxide (CO). To improve air quality and protect public health, EPD has introduced the Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation, which came in effect on 1 June 2015, to regulate emissions from machines and non-road vehicles. Starting from 1 December 2015, only approved or exempted non-road mobile machinery are allowed to be used in construction sites. Hence, with the effect of the Regulation, the emissions from PMEs are considered relatively small as compared with the tailpipe emissions from vehicles.

3.4.3.3 There is also no source of Lead (Pb) and Ozone (O₃) during the construction phase. Hence, NO₂, SO₂, CO, Pb and O₃ are therefore not considered as the key pollutants for quantitative assessment for the construction dust assessment.

3.4.4 Assessment Methodology

Dust Emission associated with the Project

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

· Heavy construction activities including soil excavation, road widening works of Sham Shui Kok Drive, construction of sewage pumping station and associated utilities connecting to existing Siu Ho Wan Sewage Treatment Works, construction of western access to Tai Ho Interchange, etc.;

· Wind erosion of all active open sites;

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

· Construction working periods of 12 hours a day from 7:00am to 7:00pm. It is assumed that construction works will be carried out on all the public holidays and weekend as well as normal working days as a very conservative case scenario.

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

Table 3.9 References of dust emission factors for different activities

Operating Sites	Activities	Equations and Assumptions	Reference
All construction sites	Heavy construction activities including site formation, site clearance, soil excavation, backfilling, temporary storage, handling and transportation of material, land clearance, cut and fill operations, haul road, etc.	E(TSP) = 1.2 tons/acre/month of activity or = 2.69Mg/hectare/month of activity E(RSP) = E(TSP) x 0.47 = 1.26 Mg/hectare/month of activity E(FSP) = E(TSP) x 0.07 = 0.19 Mg/hectare/month of activity	USEPA AP42, S.13.2.3.3
All construction sites	Wind Erosion	E(TSP)  = 0.85 Mg/hectare/yr (24 hour emission) E(RSP) = E(TSP) x 0.47 = 0.40 Mg/hectare/month of activity E(FSP) = E(TSP) x 0.07 = 0.06 Mg/hectare/month of activity	USEPA AP42, S.11.9, Table 11.9.4

Determination of Worst Assessment Year

3.4.4.3 The construction period of SPS and associated utilities will be from 2023 to 2025, western access road will be from 2024 to 2025 and Sham Shui Kok Road widening will be from 2036 to 2038.

3.4.4.4 As a conservative approach, the secondary impacts (vehicular emission impacts) would adopt the highest emission burden year in the assessment. Vehicular emission burden for RSP and FSP was calculated by EMFAC-HK v3.1.1 model, using the traffic forecast for Year 2038, which is the year with the highest traffic volume within the construction period (2023-2025, 2036-2038) and thus adopted for a conservative assessment. The results are tabulated in Table 3.10 below. It can be seen that the highest secondary contribution would occur in Year 2023 and hence it is selected as the worst assessment year.

Table 3.10            Summary of Total Daily Pollutant Emissions within Assessment Area

Year	Total RSP emission (gram/day)	Total FSP emission (gram/day)
2023	16,568	15,250
2024	15,970	14,701
2025	15,374	14,153
2036	4,856	4,480
2037	4,861	4,484
2038	4,911	4,530

Notes:

[1] RSP and FSP emission are based on traffic forecast for Year 2038 and emission factor for respective years.

[2] Value in bold is the maximum among all years.

Dust Dispersion Modelling Approach

3.4.4.5 Dust impact assessment is undertaken using the EPD approved AMS/EPA Regulatory Model (AERMOD). It is a well-known model designed for computing air dispersion. Modelling parameters including dust emission factors, particles size distributions, surface roughness, etc. are referred to EPD’s “Guidelines on Choice of Models and Model Parameters” and USEPA AP-42. Construction activities include heavy construction activities (including site clearance, soil excavation, etc.) and wind erosion of all active open sites.  Particle size distribution is estimated based on S13.2.4.3 of USEPA AP-42. Table 3.11 presents the particle size distribution of TSP, RSP and FSP adopted in the assessment.

Table 3.11 Particle size distribution in AERMOD

Particle Size (μm)	Average Particle Size (μm)	Particle Size Distribution
		TSP	RSP	FSP
0 – 2.5	1.25	7%	15%	100%
2.5 – 5	3.75	20%	42%	-
5 – 10	7.5	20%	43%	-
10 – 15	12.5	18%	-	-
15 - 30	22.5	35%	-	-
Total		100%	100%	100%

3.4.4.6 With reference to EPD’s “Guidelines on Assessing the ‘Total’ Air Quality Impacts”, the chemical transport modelling system-based approach is adopted. As the construction period for this Project will be 2023-2025 and 2036-2038, hourly air quality data from the PATH model for Year 2020 is used as the background concentrations for conservative assessment. Hourly meteorological data (including wind direction, wind speed, temperature and mixing height) for Year 2010 extracted from the PATH model are used. In addition, the mixing heights from the PATH which are lower than the minimum mixing height recorded by the Hong Kong Observatory (HKO) in Year 2010 (i.e. 121m) are capped at 121m. For the treatment of calm hours, the wind speed is capped at 1 m/s for wind speed from PATH which are lower than 1 m/s.

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

3.4.4.8 A summary of AERMOD modelling parameters that has been adopted in the construction dust assessment are given in Table 3.12 below:

Table 3.12            Modelling parameters in AERMOD

Parameters	Input	Remark
Land Use	Open water, grassland and urban, specific to each grid	Refer to Appendix 3.2 for surface characteristic parameters (e.g. Albedo, Bowen ratio, grid-specific surface roughness)
Meteorological data	Year 2010 MCIP data extracted from PATH model	Provided by EPD
Mixing Height	Year 2010 MCIP data extracted from PATH model and is capped to between 121m and 1667m as per the real metrological data recoded by Hong Kong Observatory in Year 2010	-
Anemometer Height	9m	-
Emission period	General construction activities during daytime working hours (7 am to 7 pm) Wind erosion during both day-time (7am to 7pm) and night-time (7pm to 7am of the next day)	-
Assessment heights	1.5m, 5m, 10m, 13.6m (lowest podium level), 20m, 30m, 40m, 50m, 60m, 70m, 80m above ground

3.4.4.9 It is understood that construction activities will not be taken place on the entire work sites at the same time, but to be undertaken at moving multiple work fronts spread across the work sites. For a conservative assessment, all construction works are assumed to be concurrent and all works area are assumed to be active at the same time.

3.4.4.10 As discussed in Section 2.6.4, marine transportation for construction material for the proposed development would be avoided. Dust emission from construction vehicle movement, estimated to be about 40 per hour, will generally be limited within the confined worksites area and the emission factor given in AP-42 S.13.2.3.3 has taken this factor into account. Watering facilities will be provided at every designated vehicular exit point. Construction vehicles will not assess the construction site in within the proposed development via podium level of the proposed development. All vehicles will be washed at exit points and vehicle loaded with the dusty materials will be covered entirely by clean impervious sheeting before leaving the construction site.

3.4.4.11 Upon leaving the construction site, construction vehicles will enter the North Lantau Highway (NLH) westbound, turn around at Tung Chung Interchange and enter Tuen Mun- Chek Lap Kok (TM-CLK) Link, or enter the NLH eastbound and heading to Tsing Yi. It is anticipated that construction vehicles would not enter the existing Tung Chung New Town and the planned extension. Thus dust nuisance from construction vehicle movement outside the worksites is unlikely to be significant. The routing of construction vehicles is illustrated in Appendix 3.1a.

Prediction of Vehicular Emission from Open Road

3.4.4.12 Vehicular tailpipe emissions from within the 500m assessment area, such as North Lantau Highway and Tuen Mun-Chek Lap Kok Link, are calculated by EMFAC-HK v3.1.1, based on the projected traffic data for Year 2038 coupled with emission factors for Year 2023. Traffic data in Year 2038 is considered to be conservative as it would be the highest within the construction period (2023-2025, 2036-2038), while emission factor for Year 2023 is adopted as it is the year that the dust emission would be highest (refer to Table 3.10). Appendix 3.3 presents the hourly RSP and FSP emission factors for each road link. RSP emission from vehicles has been adopted as the TSP contribution during construction phase. It should be noted that using traffic data in Year 2038 and emission factors in Year 2023 is a very conservative approach and would not occur in reality. Detailed model parameters, assumptions for EMFAC-HK are given in Appendix 3.8.

3.4.4.13 The maximum number of construction vehicles for the Project would be about 40 veh/hr during the peak construction hours.  The daily construction period would be 7am to 7pm.  Those construction vehicles will access the construction site via North Lantau Highway which has an AADT of 68,930 in 2015.  Hence, the amount of additional traffic induced on NLH is insignificant (i.e. less than 1% of minimum hourly traffic along NLH between 7am to 7pm).

3.4.4.14 The emission factors are then used for input to CALINE4 model to assess vehicular emissions impact from all existing and planned open road network. The details are given in Section 3.5.4.

Airport, Industrial and Marine Emission

3.4.4.15 For the emissions from airport operation, the prediction approach is the same as the operational air quality assessment as described in Section 3.5.4, in which the dispersion model, AERMOD and CALINE4 are used to assess the airport related emission impact. As part of the operational air quality assessment, the airport related emission inventory under the future three-runway system (3RS) in Year 2031 has been adopted, which made reference to the approved 3RS EIA report, for a conservative assessment.

3.4.4.16 Site survey and a review of Specified Process (SP) were carried out on May 2016. No SP or existing chimney is found in the vicinity of the proposed development. The previous concrete batching plant located 120m from the Project Boundary was found removed during site survey in May 2016.

3.4.4.17 Industrial emission from OWTF Phase 1 and marine emission from North Lantau Refuse Transfer Station (NLRTS) are also assessed in accordance with the methodology described in Section 3.5.4, whereas the dispersion model AERMOD is used to simulate the emission impact.

Dust Emission associated with the Concurrent Projects

3.4.4.18 As discussed in Chapter 2, the SHD Replanning Works will be carried out in 4 stages. Construction dust contribution for each stage of SHD Replanning Works are addressed in the Railway EIA.

3.4.4.19 The mitigated construction dust contribution for each stage of SHD Replanning Works is summarized in Appendix 3.11a. At each ASR, the maximum mitigated concentration among the 4 stages is adopted as the contribution from SHD Replanning Works (In case Tier 2 assessment results are available, they would be adopted, or otherwise Tier 1 results would be adopted).

Far-field Source Contribution (i.e. Future Background Air Quality)

3.4.4.20 Since construction period (Years 2023-2025, 2036-2038) is beyond the Year 2020, the hourly pollutant concentration data predicted by PATH for Year 2020 are directly adopted for as a conservative approach.

3.4.4.21 According to EPD’s “Guidelines on Choice of Models and Model Parameter”, RSP concentrations should be adjusted to account for the limited information on pollutant emissions on a larger scale.  Thus cumulative RSP concentrations have been adjusted as follows:

· 10th highest daily RSP concentration: include 26.5 μg/m³ for correction; and

· Annual RSP concentration: include 15.6 μg/m³ for correction.

3.4.4.22 No hourly FSP concentrations available form PATH model. According to EPD’s “Guidelines on the Estimation of PM2.5 for Air Quality Assessment in Hong Kong”, the conservative corrections from RSP concentrations to FSP concentrations are as follows:

· Daily: FSP = 0.75 * RSP (in µg/m³)

· Annual: FSP = 0.71 * RSP (in µg/m³)

3.4.4.23 For hourly background TSP concentrations, it is considered reasonable to assume the hourly RSP concentrations from PATH as the ambient TSP background concentrations, since the particulates of sizes larger than 10μm generated from far-field dust sources would have been largely settled before reaching the ASRs, and hence most of the particulates contributed from far-field sources affecting the ASRs will likely be of less than or equal to 10μm in size (i.e. RSP).

Prediction of the Cumulative Construction Dust Impact

3.4.4.24 The cumulative construction dust impact is a combination of the emission impacts contributed from the near field and far field sources (i.e. at local scale and background air quality impact from other concurrent and regional sources) on hourly basis.

3.4.4.25 In consideration of the number of exceedance allowance of the daily AQO (refer to Table 3.1), the pollutant concentrations beyond the AQO’s allowance limits (i.e. the 10^th highest 24-hour RSP/FSP concentrations) are presented. The annual predicted RSP/FSP concentrations are also assessed and all predicted levels are then compared with the AQOs. Besides, the 1-hour TSP concentration as stipulated under Annex 4 of EIAO-TM is also determined at each ASR.

3.4.5 Prediction and Evaluation of Environmental Impacts

3.4.5.1 The predicted maximum unmitigated 1-hour TSP concentrations, 10^th highest 24-hour and annual RSP / FSP concentrations are presented in the Table 3.13 below and detailed in Appendix 3.4. Exceedances of the TSP criteria are predicted at almost all existing ASRs. Mitigation measures are therefore required to reduce the potential air quality impact during construction phase. It should be noted that the predicted concentrations are based on very conservative assumptions, such as assuming 100% active area, assuming all construction works to be concurrent, adopting airport emission in Year 2031 and vehicular emission in Year 2023 (but using traffic data in Year 2038).

3.4.5.2 Based on the detailed results presented in Appendix 3.4, it is observed that the worst affected height is identified at 1.5m above ground for existing ASRs and at the lowest podium level for planned ASRs. To this end, contours for the cumulative unmitigated 1-hour TSP concentrations, and 10th highest 24-hour and annual RSP / FSP concentrations the worst affected level for existing and planned ASRs (i.e. 1.5m and 13.6m above ground), are plotted in Figure 3.4.

Table 3.13 Unmitigated cumulative TSP, RSP and FSP concentrations at ASRs

ASR ID	Worst Affected Height Above Ground (m)	Concentrations (µg/m^3)
		TSP	RSP		FSP
		Highest 1-hour	10^th highest 24-hour	Annual	10^th highest 24-hour	Annual
AQO		500	100	50	75	35
Existing ASRs
A1	1.5	647	97	37	62	25
A2	1.5	1715	105	37	63	25
A3	1.5	584	86	36	61	25
A4	1.5	489	84	35	61	25
A5	1.5	1198	90	36	59	25
A6	1.5	838	87	36	58	24
Planned ASRs
A101	20	262	79	33	58	23
A104	20	258	79	33	58	23
A107	20	260	79	33	58	23
A108	20	259	79	33	58	23
A113	20	253	79	33	58	23
A115	20	251	79	33	58	23
A118	20	250	79	33	58	23
A125	20	228	80	34	60	24
A128	20	228	80	34	60	24
A131	20	263	79	33	58	23
A135	20	263	79	33	58	23
A136	20	248	79	33	58	23
A139	20	244	79	33	59	23
A142	20	247	79	33	58	23
A143	20	250	79	33	58	23
A146	20	251	79	33	58	23
A149	20	258	79	33	58	23
A209	13.6	279	78	33	58	23
A211	20	245	78	33	58	23
A212	20	245	79	33	58	23
A215	20	256	78	33	58	23
A219	13.6	274	79	33	58	23
A303	20	241	78	33	58	23
A307	20	249	79	33	58	23
A308	13.6	253	78	33	58	23
A310	20	254	79	33	58	23
A313	13.6	271	79	33	58	23
A318	13.6	251	78	33	58	23
A402	20	261	79	33	58	23
A404	20	268	79	33	58	23
A407	20	280	79	33	58	23
A409	20	251	78	33	58	23
A412	13.6	238	78	33	58	23
A414	20	258	78	33	58	23
A417	20	224	78	33	58	23
A419	20	227	78	33	58	23
A422	20	263	78	34	58	23
A501	40	221	80	34	60	24
A601	20	247	79	33	58	23
A701	20	262	78	33	58	23

Note: Bold values indicate exceedance of AQO or EIAO-TM.

3.4.6 Mitigation Measures

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

· Regular watering under a good site practice should be adopted. In accordance with the “Control of Open Fugitive Dust Sources” (USEPA AP-42) as given in Appendix 3.5, watering once per hour on exposed worksites is proposed to achieve dust removal efficiency of 91.7%. These dust suppression efficiencies are derived based on the average construction site traffic of 40 per hour, average evaporation, etc. (see Appendix 3.5). Any potential dust impact and watering mitigation would be subject to the actual site conditions.  For example, for a construction activity that produces inherently wet conditions or in cases under rainy weather, the above water application intensity may not be unreservedly applied.  While the above watering frequencies are to be followed, the extent of watering may vary depending on actual site conditions. The dust levels would be monitored and managed under an Environmental Monitoring and Audit (EM&A) programme as specified in the EM&A Manual.

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

· Water spraying on any dusty materials before loading and uploading, stockpile of dusty materials, area where demolition work is carried out, area where excavation or earth moving activities are carried out, and any unpaved main haul road;

· Adoption of 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 used to aggregate fines;

· Use of regular watering to reduce dust emissions from exposed site surfaces, unpaved roads, dusty construction areas;

· Provide hoarding of not less than 2.4m high from ground level along site boundary which is next to a road or other public area;

· Provide effective dust screens, sheeting, or netting to enclose any scaffolding built around the perimeter of a building;

· Prevent placing dusty material storage piles near ASRs;

· Cover or shelter any stockpile of dusty materials;

· Provide vehicle washing facilities at all site exits to wash away any dusty materials from vehicle body and wheels before they leave the site;

· Cover any dusty load on vehicles before they leave the site; and

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

· Properly treat any exposed earth, such as by compacting or hydroseeding, within 6 months after the last construction activity.

3.4.6.3 With the implementation of the abovementioned mitigation measures, the maximum mitigated 1-hour TSP concentrations, and 10th highest 24-hour and annual RSP / FSP concentrations are calculated and presented in Table 3.14 below and detailed in Appendix 3.6. Results indicate that there are no exceedances of respective criteria predicted at existing ASRs.

3.4.6.4 According to the detailed assessment results presented in Appendix 3.6, the worst construction dust impact on each identified existing ASRs generally occurs at ground level (i.e. 1.5m above ground), which is the closest location to the at-grade construction site. ASRs located at higher level would generally be less affected by construction dust impact as particulates would likely settled or being settled before reaching the ASRs.

Table 3.14 Mitigated cumulative TSP, RSP and FSP concentrations at ASRs

ASR ID	Worst Affected Height Above Ground (m)	Concentrations (µg/m^3)
		TSP	RSP		FSP
		Highest 1-hour	10^th highest 24-hour	Annual	10^th highest 24-hour	Annual
AQO		500	100	50	75	35
Existing ASRs
A1	1.5	425	96	36	62	25
A2	1.5	358	95	35	62	24
A3	1.5/5	227	81	35	60	24
A4	1.5/5	226	80	34	60	24
A5	1.5/20	454	78	34	59	25
A6	1.5	220	78	34	58	24
Planned ASRs
A101	20	254	79	33	58	23
A104	20	249	79	33	58	23
A107	20	250	79	33	58	23
A108	20	249	79	33	58	23
A113	20	241	79	33	58	23
A115	20	238	79	33	58	23
A118	20	237	79	33	58	23
A125	20	228	80	34	60	24
A128	20	228	80	34	60	24
A131	20	257	79	33	58	23
A135	20	255	79	33	58	23
A136	20	234	79	33	58	23
A139	20	227	79	33	58	23
A142	20	228	79	33	58	23
A143	20	228	79	33	58	23
A146	20	229	79	33	58	23
A149	20	228	79	33	58	23
A209	13.6	249	78	33	58	23
A211	20	240	78	33	58	23
A212	20	245	79	33	58	23
A215	20	252	78	33	58	23
A219	13.6	257	79	33	58	23
A303	20	232	78	33	58	23
A307	20	237	79	33	58	23
A308	13.6	249	78	33	58	23
A310	20	254	79	33	58	23
A313	13.6	268	79	33	58	23
A318	13.6	247	78	33	58	23
A402	20	229	79	33	58	23
A404	20	219	78	33	58	23
A407	20	219	78	33	58	23
A409	20	238	78	33	58	23
A412	13.6	226	78	33	58	23
A414	20	237	78	33	58	23
A417	20	219	78	33	58	23
A419	20	219	78	33	58	23
A422	20	221	78	33	58	23
A501	20	221	80	33	60	24
A601	20	241	79	33	58	23
A701	20	230	78	33	58	23

3.4.6.5 Hence, contours of mitigated 1-hour TSP concentrations, and 10th highest and annual RSP / FSP concentrations at the worst affected level (i.e. 1.5m above ground) are illustrated in Figure 3.5. Contours of pollutant concentrations at 13.6m above ground are also given in Figure 3.5 to illustrate the construction dust impact on the lowest podium level of the planned ASRs under this Project. Contours also indicate that there are no exceedances at all ASRs. For planned ASRs located above 13.6m above ground, according to the detailed assessment results presented in Appendix 3.6, pollutant concentrations will generally decrease with increasing height above ground. For example, the predicted cumulative 1-hour TSP concentrations at A313 (Proposed development atop Siu Ho Wan Depot (Phase 3b)) has reduced from 268μg/m³ at 13.6m above ground to 243μg/m³ and 219μg/m³ at 20m and 50m above ground. Therefore, since the contours plot at 13.6m above ground would represent the worst case scenario for all the planned ASRs and there are no exceedance at all planned ASRs, the planned ASRs at higher level would also comply with the AQOs.

Incremental Air Quality Impact in Future Year

3.4.6.6 The predicted maximum mitigated 1-hour TSP, and 10th highest 24-hour and annual RSP / FSP project contributions throughout the construction period are therefore summarised in the Table 3.15a-c below. Breakdown of contributions from various source groups (i.e. Airport operation, vehicular emission and ambient background) have also been presented for comparison.

Table 3.15a Breakdown of mitigated highest 1-hour TSP concentrations

ASR ID	Highest 1-hour TSP Concentrations (µg/m^3)
	Project Contribution	Dust from SHO and SHD Replanning Works	Vehicles	Airport	Industrial ^[1]	Marine	Ambient Background	Total
Existing ASRs
A1	<1	316	2	4	<1	<1	103	425
A2	<1	293	6	2	<1	<1	56	358
A3	<1	<1	<1	<1	3	<1	224	227
A4	<1	<1	<1	<1	2	<1	224	226
A5	67	333	4	<1	<1	<1	49	454
A6	<1	<1	<1	<1	<1	<1	220	220
Planned ASRs
A101	<1	54	1	<1	<1	<1	197	254
A104	<1	49	2	<1	<1	<1	197	249
A107	<1	50	2	<1	<1	<1	197	250
A108	<1	49	2	<1	<1	<1	197	249
A113	1	40	2	<1	<1	<1	197	241
A115	1	37	2	<1	<1	<1	197	238
A118	1	36	2	<1	<1	<1	197	237
A125	<1	57	<1	<1	<1	<1	171	228
A128	<1	57	<1	<1	<1	<1	171	228
A131	<1	57	2	<1	<1	<1	197	257
A135	<1	55	2	<1	<1	<1	197	255
A136	1	32	2	<1	<1	<1	197	234
A139	<1	53	<1	<1	<1	<1	174	227
A142	2	27	2	<1	1	<1	197	228
A143	2	25	2	<1	1	<1	197	228
A146	<1	54	<1	<1	<1	<1	174	229
A149	<1	54	<1	<1	<1	<1	174	228
A209	<1	50	<1	<1	<1	<1	197	249
A211	<1	41	<1	<1	<1	<1	197	240
A212	<1	63	<1	<1	<1	<1	181	245
A215	<1	54	<1	<1	<1	<1	197	252
A219	<1	58	<1	<1	<1	<1	197	257
A303	<1	33	1	<1	<1	<1	197	232
A307	1	37	1	<1	<1	<1	197	237
A308	<1	50	<1	<1	<1	<1	197	249
A310	<1	73	<1	<1	<1	<1	181	254
A313	<1	69	<1	<1	<1	<1	197	268
A318	<1	48	<1	<1	<1	<1	197	247
A402	<1	54	<1	<1	<1	<1	174	229
A404	<1	<1	<1	<1	<1	<1	219	219
A407	<1	<1	<1	<1	<1	<1	219	219
A409	1	38	1	<1	<1	<1	197	238
A412	<1	12	<1	<1	<1	<1	213	226
A414	2	35	2	<1	1	<1	197	237
A417	<1	<1	<1	<1	<1	<1	219	219
A419	<1	<1	<1	<1	<1	<1	219	219
A422	<1	47	<1	<1	<1	<1	174	221
A501	<1	<1	<1	<1	<1	<1	221	221
A601	<1	59	<1	<1	<1	<1	181	241
A701	3	26	2	<1	1	<1	197	230

Note:

[1]           Refer to the contributions from OWTF Phase 1

Table 3.15b Breakdown of mitigated 10^th highest 24-hour and annual RSP concentrations

ASR ID	10^th Highest 24-hour RSP Concentrations (µg/m^3)								Annual RSP Concentrations (µg/m^3)
	Project Contribution	Dust from SHO and SHD Replanning Works	Vehicles	Airport	Industrial ^[1]	Marine	Ambient Background	Total	Project Contribution	Dust from SHO and SHD Replanning Works	Vehicles	Airport	Industrial ^[1]	Marine	Ambient Background	Total
Existing ASRs
A1	1.5	1.0	0.8	<0.1	<0.1	<0.1	92.6	95.9	0.2	1.1	0.6	<0.1	<0.1	<0.1	33.8	35.8
A2	1.3	14.5	1.7	<0.1	0.1	<0.1	77.4	95.1	0.4	1.4	0.9	0.1	<0.1	<0.1	32.4	35.3
A3	1.2	0.6	0.7	<0.1	0.2	<0.1	78.0	80.8	0.3	<0.1	0.3	<0.1	0.1	<0.1	33.8	34.5
A4	1.0	<0.1	0.4	<0.1	0.4	<0.1	78.0	80.0	0.2	<0.1	0.2	<0.1	0.3	<0.1	33.8	34.4
A5	1.4	<0.1	0.8	<0.1	<0.1	<0.1	76.0	78.3	<0.1	<0.1	0.2	<0.1	1.1	<0.1	32.8	34.2
A6	<0.1	<0.1	<0.1	<0.1	<0.1	<0.1	77.7	77.7	0.3	<0.1	0.4	<0.1	0.2	<0.1	32.8	33.8
Planned ASRs
A101	<0.1	3.6	0.2	<0.1	<0.1	<0.1	75.1	79.1	<0.1	0.2	0.4	0.1	<0.1	<0.1	32.4	33.0
A104	<0.1	1.5	<0.1	<0.1	<0.1	<0.1	77.4	79.0	<0.1	0.2	0.3	0.1	<0.1	<0.1	32.4	33.0
A107	<0.1	1.6	<0.1	<0.1	<0.1	<0.1	77.4	79.2	<0.1	0.2	0.3	0.1	<0.1	<0.1	32.4	32.9
A108	<0.1	1.6	<0.1	<0.1	<0.1	<0.1	77.4	79.1	<0.1	0.2	0.2	0.1	<0.1	<0.1	32.4	32.9
A113	<0.1	1.7	<0.1	<0.1	<0.1	<0.1	77.4	79.3	<0.1	0.2	0.2	0.1	<0.1	<0.1	32.4	32.9
A115	<0.1	4.0	0.1	<0.1	<0.1	<0.1	75.1	79.3	<0.1	0.2	0.2	0.1	<0.1	<0.1	32.4	32.9
A118	<0.1	4.1	0.1	<0.1	<0.1	<0.1	75.1	79.4	<0.1	0.2	0.2	0.1	<0.1	<0.1	32.4	32.9
A125	<0.1	1.0	<0.1	<0.1	0.4	<0.1	78.6	79.8	<0.1	0.1	0.4	0.1	<0.1	<0.1	32.9	33.6
A128	<0.1	1.4	<0.1	<0.1	0.4	<0.1	78.6	80.2	<0.1	0.1	0.4	0.1	<0.1	<0.1	32.9	33.6
A131	<0.1	1.5	<0.1	<0.1	<0.1	<0.1	77.4	79.1	<0.1	0.2	0.4	0.1	<0.1	<0.1	32.4	33.1
A135	<0.1	3.7	0.2	<0.1	<0.1	<0.1	75.1	79.1	<0.1	0.2	0.4	0.1	<0.1	<0.1	32.4	33.1
A136	<0.1	3.9	0.1	<0.1	<0.1	<0.1	75.1	79.3	<0.1	0.2	0.2	0.1	<0.1	<0.1	32.4	32.9
A139	<0.1	1.7	<0.1	<0.1	<0.1	<0.1	77.4	79.3	<0.1	0.2	0.2	0.1	<0.1	<0.1	32.4	32.9
A142	<0.1	1.7	<0.1	<0.1	0.1	<0.1	77.4	79.3	<0.1	0.1	0.2	<0.1	<0.1	<0.1	32.4	32.9
A143	<0.1	1.4	<0.1	<0.1	0.1	<0.1	77.4	79.0	<0.1	0.1	0.2	<0.1	<0.1	<0.1	32.4	32.9
A146	<0.1	1.2	<0.1	<0.1	0.1	<0.1	77.4	78.8	<0.1	0.1	0.2	<0.1	<0.1	<0.1	32.4	32.9
A149	<0.1	3.3	0.2	<0.1	<0.1	<0.1	75.1	78.7	<0.1	0.2	0.2	<0.1	<0.1	<0.1	32.4	32.9
A209	<0.1	0.7	<0.1	<0.1	<0.1	<0.1	77.4	78.2	<0.1	0.5	0.3	0.1	<0.1	<0.1	32.4	33.3
A211	<0.1	0.9	<0.1	<0.1	<0.1	<0.1	77.4	78.5	<0.1	0.2	0.3	0.1	<0.1	<0.1	32.4	33.0
A212	<0.1	1.1	<0.1	<0.1	<0.1	<0.1	77.4	78.6	<0.1	0.2	0.3	0.1	<0.1	<0.1	32.4	33.0
A215	<0.1	0.9	<0.1	<0.1	<0.1	<0.1	77.4	78.4	<0.1	0.2	0.2	0.1	<0.1	<0.1	32.4	33.0
A219	<0.1	1.1	<0.1	<0.1	<0.1	<0.1	77.4	78.6	<0.1	0.5	0.3	0.1	<0.1	<0.1	32.4	33.3
A303	<0.1	0.7	<0.1	<0.1	<0.1	<0.1	77.4	78.2	<0.1	0.2	0.3	0.1	<0.1	<0.1	32.4	33.0
A307	<0.1	1.1	<0.1	<0.1	0.1	<0.1	77.4	78.7	<0.1	0.2	0.3	0.1	<0.1	<0.1	32.4	32.9
A308	<0.1	0.7	<0.1	<0.1	0.1	<0.1	77.4	78.3	<0.1	0.4	0.3	0.1	<0.1	<0.1	32.4	33.2
A310	<0.1	1.0	<0.1	<0.1	<0.1	<0.1	77.4	78.6	<0.1	0.2	0.3	0.1	<0.1	<0.1	32.4	33.0
A313	<0.1	1.1	<0.1	<0.1	<0.1	<0.1	77.4	78.7	<0.1	0.5	0.3	0.1	<0.1	<0.1	32.4	33.2
A318	<0.1	0.6	<0.1	<0.1	<0.1	<0.1	77.4	78.1	<0.1	0.4	0.3	0.1	<0.1	<0.1	32.4	33.2
A402	<0.1	3.4	0.2	<0.1	<0.1	<0.1	75.1	78.8	<0.1	0.2	0.2	<0.1	<0.1	<0.1	32.4	32.9
A404	<0.1	3.0	0.2	<0.1	<0.1	<0.1	75.1	78.4	<0.1	0.1	0.2	<0.1	<0.1	<0.1	32.4	32.9
A407	0.1	<0.1	<0.1	<0.1	0.2	<0.1	77.4	77.8	<0.1	0.1	0.2	<0.1	<0.1	<0.1	32.4	32.9
A409	<0.1	0.6	<0.1	<0.1	0.1	<0.1	77.4	78.2	<0.1	0.2	0.3	<0.1	<0.1	<0.1	32.4	33.0
A412	<0.1	0.2	<0.1	<0.1	0.1	<0.1	77.4	77.8	<0.1	0.4	0.3	0.1	<0.1	<0.1	32.4	33.3
A414	<0.1	0.6	<0.1	<0.1	0.1	<0.1	77.4	78.2	<0.1	0.2	0.3	<0.1	<0.1	<0.1	32.4	33.0
A417	<0.1	0.1	<0.1	<0.1	0.1	<0.1	77.4	77.7	<0.1	0.2	0.3	<0.1	<0.1	<0.1	32.4	33.0
A419	<0.1	<0.1	<0.1	<0.1	0.2	<0.1	77.4	77.7	<0.1	0.1	0.3	<0.1	<0.1	<0.1	32.4	33.0
A422	<0.1	<0.1	<0.1	<0.1	0.2	<0.1	77.4	77.7	<0.1	<0.1	0.3	<0.1	<0.1	<0.1	32.4	32.9
A501	<0.1	0.1	0.2	<0.1	<0.1	<0.1	79.4	79.9	<0.1	0.1	0.3	0.1	<0.1	<0.1	32.9	33.5
A601	<0.1	1.2	<0.1	<0.1	<0.1	<0.1	77.4	78.8	<0.1	0.2	0.3	0.1	<0.1	<0.1	32.4	32.9
A701	<0.1	2.8	0.2	<0.1	<0.1	<0.1	75.1	78.2	<0.1	0.2	0.3	<0.1	<0.1	<0.1	32.4	33.0

Note:

[1]           Refer to the contributions from OWTF Phase 1

Table 3.15c Breakdown of mitigated 10^th highest 24-hour and annual FSP concentrations

ASR ID	10^th Highest 24-hour FSP Concentrations (µg/m^3)								Annual FSP Concentrations (µg/m^3)
	Project Contribution	Dust from SHO and SHD Replanning Works	Vehicles	Airport	Industrial ^[1]	Marine	Ambient Background	Total	Project Contribution	Dust from SHO and SHD Replanning Works	Vehicles	Airport	Industrial ^[1]	Marine	Ambient Background	Total
Existing ASRs
A1	<0.1	1.2	1.1	<0.1	<0.1	<0.1	59.2	61.6	<0.1	0.2	0.6	<0.1	<0.1	<0.1	24.0	24.8
A2	0.3	0.7	2.3	<0.1	0.1	<0.1	58.2	61.6	<0.1	0.2	0.9	<0.1	<0.1	<0.1	23.0	24.2
A3	<0.1	<0.1	<0.1	<0.1	0.7	<0.1	59.1	60.2	<0.1	<0.1	0.3	<0.1	0.1	<0.1	24.0	24.4
A4	<0.1	<0.1	<0.1	<0.1	0.7	<0.1	59.0	59.8	<0.1	<0.1	0.1	<0.1	0.3	<0.1	24.0	24.4
A5	<0.1	<0.1	<0.1	<0.1	<0.1	<0.1	58.3	58.7	<0.1	<0.1	0.2	<0.1	1.1	<0.1	23.3	24.6
A6	0.1	<0.1	<0.1	<0.1	<0.1	<0.1	57.5	58.1	<0.1	<0.1	0.4	<0.1	0.2	<0.1	23.3	24.0
Planned ASRs
A101	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.3	<0.1	<0.1	<0.1	23.0	23.4
A104	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.4	<0.1	<0.1	0.3	<0.1	<0.1	<0.1	23.0	23.4
A107	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.4	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A108	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.4	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A113	<0.1	0.3	<0.1	<0.1	<0.1	<0.1	58.0	58.5	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A115	<0.1	0.3	<0.1	<0.1	<0.1	<0.1	58.0	58.5	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A118	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.4	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A125	<0.1	0.4	<0.1	0.1	<0.1	<0.1	58.9	59.6	<0.1	<0.1	0.4	<0.1	<0.1	<0.1	23.3	23.8
A128	<0.1	0.5	<0.1	0.1	<0.1	<0.1	58.9	59.7	<0.1	<0.1	0.4	<0.1	<0.1	<0.1	23.3	23.8
A131	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.4	<0.1	<0.1	0.3	<0.1	<0.1	<0.1	23.0	23.4
A135	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.4	<0.1	<0.1	0.3	<0.1	<0.1	<0.1	23.0	23.4
A136	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.4	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A139	<0.1	0.3	<0.1	<0.1	<0.1	<0.1	58.0	58.5	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A142	<0.1	0.3	<0.1	<0.1	0.1	<0.1	58.0	58.5	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A143	<0.1	0.2	<0.1	<0.1	0.1	<0.1	58.0	58.4	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A146	<0.1	0.2	<0.1	<0.1	0.1	<0.1	58.0	58.4	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A149	<0.1	0.1	<0.1	<0.1	0.1	<0.1	58.0	58.4	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A209	<0.1	0.1	<0.1	<0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.4
A211	<0.1	0.1	<0.1	<0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.3	<0.1	<0.1	<0.1	23.0	23.3
A212	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.3	<0.1	<0.1	<0.1	23.0	23.4
A215	<0.1	0.1	<0.1	<0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A219	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.4
A303	<0.1	0.1	<0.1	<0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A307	<0.1	0.2	<0.1	<0.1	0.1	<0.1	58.0	58.4	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A308	<0.1	0.1	<0.1	<0.1	0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.4
A310	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A313	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.4
A318	<0.1	<0.1	<0.1	<0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.4
A402	<0.1	<0.1	<0.1	<0.1	0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A404	<0.1	<0.1	<0.1	<0.1	0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A407	<0.1	<0.1	<0.1	<0.1	0.2	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A409	<0.1	<0.1	<0.1	<0.1	0.1	<0.1	58.0	58.3	<0.1	0.2	0.2	<0.1	<0.1	<0.1	23.0	23.5
A412	<0.1	<0.1	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	<0.1	0.3	<0.1	<0.1	<0.1	23.0	23.4
A414	<0.1	<0.1	<0.1	<0.1	0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A417	<0.1	<0.1	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A419	<0.1	<0.1	<0.1	<0.1	0.2	<0.1	58.0	58.3	<0.1	<0.1	0.3	<0.1	<0.1	<0.1	23.0	23.3
A422	<0.1	<0.1	<0.1	<0.1	0.2	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A501	<0.1	<0.1	<0.1	<0.1	0.6	<0.1	58.9	59.6	<0.1	<0.1	0.3	<0.1	<0.1	<0.1	23.3	23.7
A601	<0.1	0.2	<0.1	<0.1	<0.1	<0.1	58.0	58.4	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3
A701	<0.1	<0.1	<0.1	<0.1	0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3

Note:

[1]           Refer to the contributions from OWTF Phase 1

3.4.6.7 Maximum 1-hour TSP, 10^th highest 24-hour RSP/FSP project contributions ranged from 1 – 67 μg/m³, 0.1 – 1.5 μg/m³ and 0.1 - 0.3 μg/m³, while maximum annual RSP/FSP project contributions are 0.4 μg/m³ and 0.1 μg/m³.

3.4.6.8 Contributions on 1-hour TSP from other sources are comparatively small and it is considered that the background contributions is the major contributor to the cumulative construction dust impact. On the other hand, background contributions from far-field sources are identified as the major contributor of 10th highest 24-hour and annual RSP / FSP concentrations. In particular, FSP contributions are small at all ASRs, indicating that construction works are not major source of FSP.

3.4.7 Residual Environmental Impacts

3.4.7.1 With the implementation of the mitigation measures as stipulated in the Air Pollution Control (Construction Dust) Regulation, dust control measures, including watering once per hour on exposed worksites and haul road, and good site practices, the predicted 1-hour TSP, 24-hour and annual RSP / FSP concentrations on area in the vicinity of the construction sites would comply with the respective criteria. Hence, adverse residual air quality impacts during construction phase are not anticipated.

3.5 Operational Air Quality Assessment

3.5.1 Assessment Area

3.5.1.1 As stated in the Section 3.3, the assessment area for operational air quality impact assessment should also be generally defined by a distance of 500m from the boundary of the Project. Figure 3.7 illustrates the extent of assessment area. The three tier source contributions from near-field and far-field pollution sources should be predicted using local-scale and regional-scale models for cumulative impact assessment.

3.5.2 Identification of Pollution Sources within the Study Area

Vehicular Emission from Open Road

3.5.2.1 As discussed in Section 3.5.3, the NO₂, RSP and FSP are the key air pollutants generated from road traffic emissions during operational phase of the Project. Other than vehicular emissions from the concurrent projects, such as the HKLR, HKBCF, TM-CLK Link, Development of North Commercial District on Airport Island, Topside Development at HKBCF, Road P1 as part of Tung Chung New Town Extension, as well as all the induced traffic from planned developments would also have cumulative air quality impact on nearby ASRs.

Industrial Emission

3.5.2.2 The Organic Waste Treatment Facility (OWTF) under construction is located 670m away from the proposed development, as illustrated in Figure 3.8. Site survey and a review of Specified Process (SP) were carried out on May 2016. No SP or existing chimney is found in the vicinity of the proposed development. The previous concrete batching plant located 120m from the Project Boundary was found removed during site survey in May 2016.

Marine Emission

3.5.2.3 There are emissions from marine vessels at the North Lantau Refuse Transfer Station for transferring refuse from NLRTS, located 100m away from the Project Boundary and illustrated in Figure 3.8, to West New Territories Landfill (WENT).

Odour Emission

3.5.2.4 The SHW Sewage Treatment Works (SHWSTW), North Lantau Refuse Transfer Station (NLRTS) and the Organic Waste Treatment Facility (OWTF) under construction, as illustrated in Figure 3.8, are the major odour source within 500m of the Project Boundary. Odour impact from SHWSTW, NLTRS and OWTF was assessed in the approved EIA for Organic Waste Treatment Facilities Phase I (AEIAR-149/2010). The emission information has therefore been included in this odour impact assessment. Where applicable, the information presented in the VEP (i.e. Application No. VEP-488/2015) for OWTF have been adopted for purpose of cumulative air quality impact assessment

Emission from Construction of SHD and SHO

3.5.2.5 Dust emission (i.e. RSP and FSP) will be generated from construction activities associated with SHO and SHD Replanning Works, located in close proximity of the SHD Topside Development.

3.5.3 Key Representative Pollutants

3.5.3.1 As discussed in Section 3.1, the APCO (Cap 311) and its subsidiary regulations define statutory AQOs for 7 common air pollutants including NO₂, SO₂, RSP, FSP, CO, O₃ and lead. According to Appendix B of the EIA Study Brief, the key / representative air pollutant parameters for the Project shall be identified, including the types of pollutants and the averaging time concentration. 

3.5.3.2 The Project is to plan for new development areas. No major polluting emission is anticipated except the associated new roads for supporting the new development.  The air quality pollutant source during the operational phase of the Project would therefore be the emission from the induced traffic travelling on the new and existing roads.  The tailpipe emission would comprise a number of pollutants, including NO_x, RSP, SO₂, CO, etc. As discussed in the following sections, only the NO₂, RSP and FSP are considered the key air quality pollutant for the project and the concentrations of the other pollutants are very low and hence are not considered as the key pollutants for the purposes of this air quality assessment.  The issue on O₃ which is highly influenced by the regional situation would also be discussed.

Nitrogen Dioxide (NO₂)

3.5.3.3 Nitrogen oxides (NO_x) is known to be one of the pollutants emitted by vehicles.  According to the 2015 Hong Kong Emission Inventory Report published by EPD, which is the latest available information by the time of preparing this report, the dominant source of NOx generated in HK is the navigation which constitutes about 37% of the total in 2015. Road transport is the third largest NOx emission group, accounting for about 18% of the total while other combustion including for industrial purposes accounted for 11% of the total (see table below).

Table 3.16 The emission percentage and the amount of NO_x in Hong Kong (2015)

Pollutant Source Categories	NOx Emission % ^[1]	NOx Emission (tonnes)^[1]
Public Electricity Generation	28%	26,090
Road Transport	18%	16,200
Navigation	37%	33,900
Civil Aviation	5%	5,000
Other Combustion	11%	10,450
Non-combustion	N/A	N/A
Biomass Burning	<1%	60
Total	100%	91,700

Note:

[1]           Figures extracted from 2015 Hong Kong Emission Inventory Report (http://www.epd.gov.hk/epd/sites/default/files/epd/2015_EI_Report_Eng_v2.pdf)

3.5.3.4 Together with VOC and in the presence of O₃ under sunlight, NO_x would be transformed to NO₂.  As discussed in Section 3.2, the latest 5-year average of annual NO₂ concentrations in Tung Chung is about 107% of the prevailing AQO.

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

Respirable Suspended Particulates (RSP or PM₁₀) and Fine Suspended Particulates (FSP or PM_2.5)

3.5.3.6 Respirable Suspended Particulates (RSP or PM₁₀) refers to suspended particulates with a nominal aerodynamic diameter of 10µm or less. According to the EPD’s data, and other research studies (Tian et al., 2011 & Wie-Zhen et al., 2008), road vehicles, particularly diesel vehicles, are one of the sources of RSP in Hong Kong. Fine Suspended Particulates (FSP or PM_2.5) refers to suspended particulates with a nominal aerodynamic diameter of 2.5µm or less.  

3.5.3.7 According to the latest statistics of 2015 Hong Kong Emission Inventory Report, road transport only accounted 9% and 10% of the total RSP / FSP emissions while navigation accounted for 34% and 39% respectively.  As discussed in Section 3.2, the latest 5-year average of the annual RSP an FSP concentrations in Tung Chung are about 78% and 69% of the respective prevailing AQOs.

Table 3.17 The emission percentage and the amount of RSP in Hong Kong (2015)

Pollutant Source Categories	RSP		FSP
	Emission (%)	Emission (tonnes)	Emission (%)	Emission (tonnes)
Public Electricity Generation	11%	580	7%	290
Road Transport	9%	490	10%	450
Navigation	34%	1,860	39%	1,690
Civil Aviation	1%	50	1%	50
Other Combustion	15%	800	17%	740
Non-combustion	17%	910	11%	470
Biomass Burning	14%	740	14%	600
Total	100%	5,430	100%	4,300

Note:

[1]           Figures extracted from 2015 Hong Kong Emission Inventory Report (http://www.epd.gov.hk/epd/sites/default/files/epd/2015_EI_Report_Eng_v2.pdf)

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

Sulphur Dioxide (SO₂)

3.5.3.9 According to the latest statistics of 2015 Hong Kong Emission Inventory Report, the dominant source of Sulphur Dioxide (SO₂) in Hong Kong is navigation, which constitutes the majority of the emissions (about 59%).  Given the Air Pollution Control (Marine Light Diesel) Regulation came in force from 1 April 2014, the sulphur content of the Marine Light Diesel (MLD) is limited to 0.05%. In addition, according to the Legislative Council Brief (file ref: Annex 4 to EP 150/NV/24), the sulphur content of marine petrol has a limit of 0.001%. The introduction of sulphur content limit would therefore help reducing the SO₂ emission from navigation in Hong Kong.

3.5.3.10 Although SO₂ is also one of the pollutants emitted by vehicles, road transport is the smallest emission source of SO₂ and only constitutes <1% of the total SO₂ (see the following table). The introduction of ultra-low sulphur diesel for vehicle fleet in Year 2000 has also helped reducing the SO₂ emission in Hong Kong.

Table 3.18 The emission percentage and the amount of SO₂ in Hong Kong (2015)

Pollutant Source Categories	SO2 Emission % ^[1]	SO2 Emission (tonnes)^[1]
Public Electricity Generation	37%	7,280
Road Transport	<1%	40
Navigation	59%	11,460
Civil Aviation	3%	510
Other Combustion	1%	240
Non-combustion	N/A	N/A
Biomass Burning	<1%	10
Total	100%	19,540

Note:

[1]           Figures extracted from 2015 Hong Kong Emission Inventory Report (http://www.epd.gov.hk/epd/sites/default/files/epd/2015_EI_Report_Eng_v2.pdf)

3.5.3.11 As discussed in Section 3.2, the latest 5-year average of the 4^th-highest 10-minute and 24-hour SO₂ concentrations in Tung Chung are only 16% and 24% of the respective prevailing AQOs.  This clearly indicates that the AQOs for SO₂ could be well achieved with great margin in the study area.  Given that road transport and airport only contribute a very small amount of SO_2, sulphur content of the MLD are controlled under the Air Pollution Control (Marine Light Diesel) Regulation, and there is still a large margin to the AQO compared to the other pollutants such as RSP and NO₂, it is considered appropriate to select RSP and NO₂, but not SO₂ as the key pollutants for quantitative assessment for the operational phase of the Project.

Ozone (O₃)

3.5.3.12 Unlike other pollutants such as NO_x, O₃ is not a primary pollutant emitted from man-made sources but is formed by a set of complex chain reactions between various chemical species, including NO_x and VOC, in the presence of sunlight.  According to Sun et al. ^{[3-1, 3-2]} the rate of formation of O₃, also known as Ozone Production Efficiency, depends not only on NO_x and VOC levels, but atmospheric oxidation, temperature, radiation, and other meteorological factors in the atmosphere of different regions. The formation of O₃ generally takes several hours to proceed (EPD, 2015) and therefore O₃ recorded locally could be attributed to emissions generated from places afar.

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

3.5.3.14 In addition, the EPD’s “Air Quality in Hong Kong 2015” report [3-3] stated that NOx emissions from motor vehicles and chimneys have the potential to react with and remove O₃ in the air, and regions with heavy traffic normally have lower ozone levels than areas with light traffic. It is therefore possible that the Project may contribute to a decrease in O₃ in the immediate area along main roads. O₃ is therefore not considered as a key parameter in this assessment.

Carbon Monoxide (CO)

3.5.3.15 Carbon Monoxide (CO) is one of the primary pollutants emitted by road transport. According to the latest 2015 Hong Kong Emission Inventory Report published by EPD, CO emissions from road transport contributed about 51% of total CO emission in 2015 (see the table below).

Table 3.19 The emission percentage and the amount of CO in Hong Kong (2015)

Pollutant Source Categories	CO Emission % ^[1]	CO Emission (tonnes) ^[1]
Public Electricity Generation	6%	3,580
Road Transport	51%	29,700
Navigation	23%	13,280
Civil Aviation	7%	3,950
Other Combustion	10%	5,920
Non-combustion	N/A	N/A
Biomass Burning	3%	1,720
Total	100%	58,150

Note:

[1]           Figures extracted from 2015 Hong Kong Emission Inventory Report (http://www.epd.gov.hk/epd/sites/default/files/epd/2015_EI_Report_Eng_v2.pdf)

3.5.3.16 It is understood that road transportation is the dominant source of CO emission; nevertheless, the air quality impact due to CO is still relatively minor considering its existing concentrations (see Table 3.21).

3.5.3.17 It is clearly indicated that the AQOs for CO could be well achieved with great margin in the study area. The highest 1-hour CO concentration and highest 8-hour average CO concentration in Tung Chung are only 7% and 18% of their respective prevailing AQOs, which are both far below the criteria.  Given that there is still a large margin to the AQO compared to the other pollutants such as RSP and NO₂, it is considered appropriate to select RSP and NO₂, but not CO as the key pollutants for quantitative assessment for the operational phase of the Project.

Toxic Air Pollutants (TAPs)

3.5.3.18 There are six kinds of Toxic Air Pollutants (TAPs) routinely monitored in HK, including diesel particulate matters, polychlorinated biphenyls (PCBs), dioxins, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), carbonyls, and toxic elemental species. While there is no AQO for these TAPs, discussion on whether TAPs are considered as representative air pollutions are presented in previously approved EIAs, including EIA for Tung Chung New Town Extension(AEIAR-196/2016).

3.5.3.19 Dioxins, carbonyls, PCBs and most toxic elemental species are not considered primary sources of vehicular emissions, and hence, these three TAPs are not considered as key / representative air pollutants for the operational air quality assessment.

3.5.3.20 Vehicular emissions may be a source of diesel particulate matters, PAHs and VOCs.  Elemental carbon, which constitutes a large portion of diesel particulate matters mass, is commonly used as a surrogate for diesel particulate matter. According to the data from EPD, the elemental carbon showed a significant decrease in concentration in Mong Kok by 47.5% from 2001 to 2009, and Tsuen Wan by 51.3% from 1999 to 2009. This is because the implementation of EURO III vehicle emission standard to goods vehicle and bus in 2001 and EURO IV standard to all types of vehicle in 2006-2007 ^[3-9].  It is not considered as a key air pollutant for the operational air quality assessment.

3.5.3.21 Currently, no ambient air quality standards have been set for PAHs.  However, with reference to US and European Community air quality guidelines, the European commission has a very stringent guideline concentration for PAHs.  According to the latest EPD study report in 2015 - “Air Quality in Hong Kong 2015”, the concentration of PAHs (Benzo[a]pyrene, BaP) at the Tsuen Wan and Central/Western monitoring stations was 0.12 and 0.06 ng/m³ respectively in 2015 which was still much lower than the guidelines of European Communities of 1ng/m³.

Table 3.20 Comparison of TAPs concentration in Hong Kong (2015) and the EU Air Quality Standards

Air Pollutants	Guidelines / Standards (ng/m^3)	Highest Avg Conc at Tsuen Wan station of Hong Kong (ng/m^3)	Highest Avg Conc at Central/Western station of  Hong Kong (ng/m^3)	Compliance
	EU			EU
PAHs (BaP)	1 (Annual Average)^[1]	0.12 (Annual Average)^[2]	0.06 (Annual Average)^[2]	Well Achieved

Note:

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

[2]           Referenced from http://www.aqhi.gov.hk/api_history/english/report/files/AQR2015e_final.pdf.

3.5.3.22 There are different standards for different VOC compounds. According to the latest EPD study report in 2015 – “Air Quality in Hong Kong 2015”, benzene, 1-3 butadiene, formaldehyde and perchloroethylene are the VOCs that may have more health concern, and the USEPA also identified benzene and 1-3 butadiene are carcinogenic.

Table 3.21 Comparison of VOCs concentration in Hong Kong (2015) and the EU Air Quality Standards

TAP	Guidelines / Standards (μg/m^3)	Highest Avg Conc at Tsuen Wan station (μg/m^3)	Highest Avg Conc at Central/Western station (μg/m^3)	Compliance
Benzene	5 (Annual Average) ^[1]	2.21	1.11	Well Achieved
1-3 butadiene	2.25 (Running Annual Average) ^[1]	0.12	0.07	Well Achieved
Formaldehyde ^[2]	9 (Annual Average)^[3]	3.73	-	Well Achieved
Perchloroethylene	40 (Annual Average)^[4]	0.46	0.64	Well Achieved

Note:

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

(https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/69336/pb12654-air-quality-strategy-vol1-070712.pdf).

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

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

[4]   Referenced from the Integrated Risk Information System (IRIS), USEPA (https://cfpub.epa.gov/ncea/iris2/chemicalLanding.cfm?substance_nmbr=106).

3.5.3.23 As shown in the above table, the measured VOCs concentration in Hong Kong urban area is far below the UK and US standards.  Also, according to 2015 Hong Kong Air Pollutants Emission Inventory, the VOCs level in 2015 was 65% lower compared to 1997 level due to the EPD progressive improvement of EURO standard vehicles over the past two decades.  With reference to the EPD’s 2015 Hong Kong Emission Inventory Report, vehicular emission is also not the primary source of VOCs, accounting for about 18% of the total in Hong Kong. Besides, according to another study - “Seasonal and diurnal variations of volatile organic compounds (VOCs) in the atmosphere of Hong Kong”, benzene, and 1-3 butadiene only contributed about 6-13% of overall vehicular emission VOCs. In other words, only 1.1-2.3% of the overall VOC emissions in Hong Kong are benzene and 1-3 butadiene contributed by vehicular emission.

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

Lead (Pb)

3.5.3.25 As leaded petrol had been banned in Hong Kong in 1999, it is no longer considered as a primary source in Hong Kong.  According to the “Air Quality in Hong Kong 2015” report from EPD, the highest measured 3-month averaged lead level within Hong Kong was recorded in Yuen Long at 0.024 μg/m³. The measured concentration is much lower than the 3-month AQO of 1.5 μg/m³. Therefore, lead is not considered as a key / representative air pollutant for the operational air quality assessment.

3.5.3.26 As discussed in the above sections, NO₂, RSP and FSP have been concluded to be the representative air pollutants. These three pollutants are stipulated in the existing HKAQO.

3.5.4 Assessment Methodology

General

3.5.4.1 The area for air quality impact assessment should be generally defined by a distance of 500m from the boundary of the Subject Site and associated area for utilities.

3.5.4.2 The assessment has evaluated the impacts arising from three classes of emission sources depending on their distance from the project site, including:

(1) Project induced contribution;

(2) Pollutant-emitting activities in the immediate neighbourhood; and

(3) Other contributions from pollution not accounted for by (1) and (2).

3.5.4.3 All sources within 500m assessment area (i.e. (1) and (2)) are considered as near-field source impacts and are predicted using local-scale models. These sources include vehicular emission from existing road network. Although the Hong Kong International Airport (HKIA) is located outside 500m assessment area, it has been included in the near-field assessment in this EIA.

3.5.4.4 Other far-field pollution source impacts (3) which are beyond 500m from the Project (i.e. background concentration), are predicted using regional scale model – Pollutant in the Atmosphere and the Transport over Hong Kong, PATH. In PATH model, all major emission sources including public electricity generation, civil aviation, road transport, navigation, industries, other fuel combustion and non-combustion sources covering both HKSAR and PRDEZ are considered

3.5.4.5 The cumulative operational air quality impact is then a combination of the contributions from the near-field and far-field sources.

Determination of Assessment Year

3.5.4.6 According to Appendix B, Clause 5 (iv) of the EIA Study Brief for the Project, the air pollution impacts of future road traffic shall be calculated based on the highest emission strength from road within the next 15 years after the first population intake year of the Project or within the next 5 years after the full population intake of the Project, whichever is later. The selected assessment year should represent the highest emission scenario, given the combination of emission factors and traffic flow for the selected year.

3.5.4.7 Vehicular tailpipe emissions have been calculated by the EMFAC-HK provided by EPD. The EMFAC-HK v.3.1.1 published in February 2016 has been employed. The emission refers to vehicular emission from road networks within 500m of the site boundary (e.g. NLH, TM-CLK Link).

3.5.4.8 Based on the tentative programme, the first population intake of the Project will commence in Year 2026 and full commissioning in Year 2038. EMFAC-HK models are carried out for Year 2026, 2030, 2034, 2038 (full population intake), 2041 (15 years after first commissioning) and 2043 (5 years after full population intake) to determine the highest emission and hence the worst assessment year. The traffic forecast data is given Appendix 3.7. The methodology, key model assumptions and results (including emission factors) are presented in Appendix 3.8.

3.5.4.9 The total NO_x, RSP and FSP emissions from nearby road networks predicted by EMFAC-HK based on the traffic forecast are summarized in the table below. Results indicate that the highest NO_x, RSP and FSP emission scenarios would likely occur in Year 2026 and hence is taken as the worst assessment year for the purpose of this operational air quality assessment. In addition, it can also be seen from Table 3.22 that, despite the continuous increase in the Vehicle-km Travelled (VKT), a progressive decrease in NO_x, RSP and FSP emissions from vehicle tailpipe is observed up to 2034, 2038 and 2038 respectively, which is anticipated as a result of the implementation of emission reduction measures over motor vehicles by the Hong Kong Government, e.g. introductions of Euro V vehicle emission standards in 2012 and Euro VI tentatively in 2016, phasing out pre-Euro IV diesel commercial vehicles by end 2019, etc. These measures on controlling vehicular emission would progressively reduce roadside air pollution.

Table 3.22 Summary of Total Daily Pollutant Emissions within Assessment Area

Year	Total NOx Emission (gram/day)	Total RSP Emission (gram/day)	Total FSP Emission (gram/day)	Total Veh-km Travelled (VKT/day)
2026	219,258	9,245	8,511	790,387
2030	187,099	7,749	7,138	959,781
2034	158,841	4,869	4,490	1,105,696
2038	171,791	4,911	4,530	1,196,262
2041	180,800	5,519	5,091	1,216,520
2043	183,009	5,587	5,153	1,228,729

Note:

[1]           Values in bold are the maximum values among the Scenario Years.

3.5.4.10 Results from Table 3.22 indicates that the Year 2026 is the worst scenario year for proposed SHD Topside Development. It should be noted that the Railway EIA has conducted quantitative construction dust impact assessment for 4 stages, which covers 2019-2034 while the operational air quality assessment was conducted qualitatively. During operational stage of the SHD Topside Development, the SHD replanning works would still be under Stage 2 to 4 construction, thus the cumulative air quality impacts have been included. Given the nature of the SHD replanning works, the key pollutants relevant to the Railway EIA are TSP, RSP and FSP.

3.5.4.11 EMFAC-HK model has been adopted in both the SHD Topside Development EIA and the Railway EIA to determine the vehicular emission factors for RSP and FSP, which are based on the same set of traffic forecast prepared by the Traffic Consultant. By adoption of the assumptions in Railway EIA, the assessment results showed that the RSP and FSP levels at ASRs due to vehicular emission impact would only have minor difference by less than 1μg/m³. Since the pollutant concentration contribution from vehicle emissions is not significant and there are still large margin for the respective AQOs, it is also considered that the difference would not affect the compliance against AQO.

Prediction of Vehicular Emission from Open Road

3.5.4.12 The EMFAC-HK calculates the hourly vehicular emission (in tonne) for each road category. The hourly emission rates for each vehicle class (in gram per mile per vehicle) are obtained by dividing the hourly emissions calculated in the EMFAC-HK by the VKT for the respective hour. The calculation of the NOx, RSP and FSP emission factors for different road groups are given in Appendix 3.9.

3.5.4.13 Since population intake years for Phase 2, 3, 4a and 4b/c are 2030, 2034, 2035 and 2038 respectively, in which there will be an improving trend in air quality conditions in Years beyond 2026. As a conservative approach, it is assumed the planned ASRs in Phases 2, 3 and 4 would be existed in the assessment year, Year 2026, and all the proposed roads are assumed to be exist in the assessment year so that the predicted operational air quality impact on these ASRs would be on the high side.

3.5.4.14 The USEPA approved near field air dispersion model, CALINE4 developed by the California Department of Transport is used to assess vehicular emissions impact from all existing and planned open road network.

3.5.4.15 Grid-specific meteorological data for Year 2010 extracted from EPD’s PATH model is adopted in CALINE4 model, including relevant temperature, wind speed, direction and mixing height. The stability classes are estimated from PCRAMMET model. The mixing height is capped to between 121m and 1667m as per the real meteorological data. For the treatment of calm hours, the wind speed is capped at 1 m/s for wind speed from PATH which are lower than 1 m/s.

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

Table 3.23 Summary of wind standard deviation for surface roughness

Period / Location/ Parameters		Assumptions
Proposed Development (Grid 21_32)	Surface roughness (cm)	100
	Wind standard deviation (degrees)	1) 32.9 for A & B Stability Classes; 2) 25.6 for C Stability Class; 3) 18.3 for D Stability Class; 4) 11 for E Stability Class; and 5) 5.6 for F Stability Class.
Outside Proposed Development (Grids 20_31, 20_32, 21_31, 22_32, 22_33)	Surface roughness (cm)	50
	Wind standard deviation (degrees)	1) 28.6 for A & B Stability Classes; 2) 22.3 for C Stability Class; 3) 15.9 for D Stability Class; 4) 9.5 for E Stability Class; and 5) 4.8 for F Stability Class.

3.5.4.17 Owing to the constraint of the CALINE4 model in modelling elevated roads higher than 10m, the road heights of elevated road sections in excess of 10m high above local ground or water surface will be set to 10m in the model. However, sections of the TM-CLK Link within the 500m Assessment Area are higher than 10m above ground while all other roads are lower than 10m above ground. Thus contribution from the TM-CLK Link and other roads is modelled separately.

3.5.4.18 A sensitivity test has therefore been carried out to identify contribution from the TM-CLK Link at various heights. For all the relevant parameters (i.e. 1-hour NO₂, 24-hour RSP and FSP, annual NO₂, RSP and FSP), contributions from vehicles on TM-CLK Link at ASR A125, the ASR closest to the TM-CLK Link, have been calculated at 1.5m, 2m, 3m, and so forth up to 20m above ground. The results are shown in Appendix 3.11b, which shows that the vehicle emission contribution from TM-CLK Link for each parameter is the highest at 1.5m above ground.

3.5.4.19  As a conservative assumption, the maximum contribution (i.e. 1.5m above ground) from the TM-CLK Link is adopted for all assessment heights at each ASR. For all other roads, the contribution from vehicle emissions at each ASR and each assessment height are directly adopted.

3.5.4.20 There are no existing noise barriers along the roads (e.g. NLH) in the vicinity of the Project. Instead of construction of noise barriers, mitigation measures to be adopted include single-aspect building design and fixed windows, which would not cause secondary environment impact. Thus assessment on secondary environment impact due to construction of new noise barriers is not required.

3.5.4.21 RSP and FSP emission rates for 2026 are directly adopted as the input for CALINE4 while NO_x emission factors are separated into initial (tailpipe) NO₂ and residual NO_x emission rates as follows:

· Initial NO₂ to NO_x (NO₂/NO_x) ratio for different vehicle and road types, shown in Appendix 3.9, have been calculated from EMFAC-HK results;

· Initial NO₂ emission factor for individual vehicle types have been derived from initial NO₂/NO_x ratio, presented in Appendix 3.9; and

· Residual NO_x emission factor is determined by subtracting the initial NO₂ emission factor from total NO_x emission factor for individual vehicle types.

3.5.4.22 Initial NO₂ and residual NO_x, RSP and FSP emission factors, shown in Appendix 3.9, are inputted to CALINE4 models. Modelling parameters for CALINE4 are listed in Table 3.24.

Table 3.24 Model parameters for CALINE4

Parameter	Input
Meteorological Data	Year 2010 MCIP data extracted from PATH model
Mixing Height	Year 2010 MCIP data extracted from PATH model and is capped to between 121m and 1667m as per the real metrological data recoded by Hong Kong Observatory in Year 2010
Stability Class	Estimated from PCRAMMET Model
NOx to NO2 Ratio	Ozone Limiting Method (initial NO2/NOx ratios from 0 to 1 were adopted for the initial NO2 and residual NOx models respectively)

Vehicular Emission from Proposed Public Transport Interchange (PTI) and Car Parks

3.5.4.23 According to the current development plan, a public transport interchange (PTI) is proposed under the podium near the SHO. Within the PTI, engines shall be switched off while waiting as required under the Motor Vehicle Idling (Fixed Penalty) Ordinance. Furthermore, adequate ventilation system will be provided to avoid accumulation of aerial emissions within the PTI. The ventilation system will be designed in accordance to EPD’s Practice Note on “Control of Air Pollution in Semi-Confined Public Transport Interchanges” (ProPECC PN 1/98). Specifically, the exhaust air outlets should be located away from nearby residents or other receptors to avoid causing an air pollutant nuisance. If necessary, control equipment such as filters or scrubbing units should be used to minimize the pollution caused to the surroundings. The ventilation system should also be maintained at regular intervals to ensure proper operation of the ventilation system. In addition, car parks are proposed under the podium. A similar ventilation system will be installed within car parks. By implementing these measures, air quality impact from the proposed PTI and car parks is not anticipated. As there is no significant air quality impact during the operation of PTI and car park, quantitative assessment is not adopted to address the air quality implications.

Airport Emission from HKIA

3.5.4.24 In the approved 3RS EIA, the worst assessment year was determined based on the highest aircraft emission scenario, and it was identified to be occurred in Year 2031. Emissions from airport operation presented in the approved 3RS EIA are directly adopted for assessing the cumulative air quality impact as a conservative approach.

3.5.4.25 Details on emissions strengths, emission characteristics and modelling parameters shall be referred to the approved 3RS EIA Study. CALINE4 (for airside vehicles) and AERMOD (for sources other than airside vehicles) models are used to assess the air quality impact from airport related activities.

3.5.4.26 Grid-specific meteorological data for Year 2010 extracted from the EPD’s PATH model is adopted in AERMOD model, including relevant temperature, wind speed, wind direction, etc. Mixing heights deduced from AERMET that are lower than the lowest mixing height recorded by the HKO in Year 2010 (i.e. 121 m) are capped at 121 m to align with the real meteorological data. Similarly, mixing heights deduced from AERMET that are higher than the highest recorded mixing height in Year 2010 (i.e. 1667m) are capped at 1667 m as per the highest mixing height recorded. Surface roughness is separated into 12 zones with heights corresponding to the land use characteristics, as given in Appendix 3.2.

3.5.4.27 Ozone Limiting Method (OLM) has also been adopted for conversion of NO_x to NO₂ concentrations. With reference to the approved 3RS EIA, the following initial NO₂/NO_x ratios for various emission sources have been adopted:

Table 3.25 Summary of initial NO₂/NO_x ratios (referenced from the 3RS EIA)

Source	Initial NO2 / NOx Ratio
Aircraft LTO (Take-off)	5.3%
Aircraft LTO (Climb-out)	5.3%
Aircraft LTO (Approach)	15%
Aircraft LTO (Taxi-in and Taxi-out)	37.5%
Vehicular Tailpipe	28%
Other sources (e.g. Engine Run-Up Facilities, etc.)	10%

Industrial Emission from OWTF Phase 1

3.5.4.28 Chimney emissions from the committed OWTF Phase 1 have been referenced to the approved EIA Study “Organic Waste Treatment Facilities, Phase 1” (AEIAR-149/2010). It is understood that variations of Environmental Permit has been approved in February 2013 (Application No. VEP-394/2013), May 2013 (Application No. VEP-403/2013) and November 2015 (Application No. VEP-488/2015) due to changes in reference design of OWTF. As presented in the supporting document for the latest VEP (VEP-488/2015), it is found that the stack locations and stack heights are changed from those in the approved OWTF Phase 1 EIA, while the chimney emission rates remain unchanged. Hence, the information presented in the VEP is adopted for purpose of cumulative air quality impact assessment. The assumptions are summarized in Appendix 3.10.

3.5.4.29 Emissions from the chimneys are modelled as “Point” source in AERMOD. OLM is adopted for conversion of NO_x to NO₂, using the predicted O₃ and NO₂ levels from PATH model. According to EPD’s “Guidelines on Choice of Models and Model Parameters”, the industrial NO₂ emission is assumed to be 10% of NO_x.

Marine Emission from NLRTS

3.5.4.30 It is noted from site observations that the barges arriving and leaving the NLRTS would take a generally north bound route towards Urmstrom Road to leave NLRTS, and vice versa. Further discussion with the NLRTS operator further confirmed that those marine vessels will generally take the shortest route and via Urmstrom Road towards the WENT Landfill, except in rare occasions when this northern route is temporarily blocked.

3.5.4.31 Reference has also been made to the approved EIA Study “Organic Waste Treatment Facilities, Phase 1” (AEIAR-149/2010). According to the variations of Environmental Permit, approved in February 2013 (Application No. VEP-394/2013), May 2013 (Application No. VEP-403/2013) and November 2015 (Application No. VEP-488/2015). According to their assessment, marine source locations are aligned in the southwesterly direction which would represent a more conservative case as far as the receivers in the Topside Development is concerned. The current assessment has therefore adopted the southwestern route instead of the northern route. The assumptions adopted for the current assessment are summarized in Appendix 3.10.

3.5.4.32 Emissions from the chimneys are modelled as “Point” source in AERMOD. OLM is adopted for conversion of NO_x to NO₂, using the predicted O₃ and NO₂ levels from PATH model. According to EPD’s “Guidelines on Choice of Models and Model Parameters”, the industrial NO₂ emission is assumed to be 10% of NO_x.

Construction Activities at SHD

3.5.4.33 During the operational years (2026-2034) of the Project, Stages 2 to 4 SHD Replanning Works will still be under construction concurrently. As far as the cumulative air quality impact is concerned, the construction dust impact arising from the SHD construction works on planned ASRs in SHD Topside Development has been assessed by the Railway EIA (i.e. EIA for the SHO and SHD Replanning Works). In order to achieve a conservative assessment for each ASR and for each level, the maximum mitigated dust emission contribution (i.e. RSP and FSP) among Stages 2 to 4 is adopted as the contribution from SHD Replanning Works (In case Tier 2 assessment results are available, they would be adopted, or otherwise Tier 1 results would be adopted). The contribution from SHD Replanning Works are presented in Appendix 3.11a.

Prediction of the Far Field Source Contribution (i.e. Future Background Air Quality)

3.5.4.34 The PATH will be used to quantify the future background air quality impacts from various far field sources outside 500m of the site boundary, including those in PRDEZ, the HKIA, power plants in HKSAR, marine vessels and road transports over the whole territory etc. The emission control measures from Section 3.2 have been incorporated to the PATH.

3.5.4.35 Emission from motor vehicles and the HKIA (2-runway system) are included in the PATH model. As a conservative approach, the hourly pollutant concentration data predicted by PATH for Year 2020 provided by EPD are directly adopted in the calculation of cumulative impact as a conservative assumption.

3.5.4.36 According to EPD’s “Guidelines on Choice of Models and Model Parameter”, RSP concentrations should be adjusted to account for the limited information on pollutant emissions on a larger scale.  Thus cumulative RSP concentrations have been adjusted as follows:

· 10th highest daily RSP concentration: include 26.5 μg/m³ for correction

· Annual RSP concentration: include 15.6 μg/m³ for correction

3.5.4.37 No hourly FSP concentrations available form PATH model. According to EPD’s “Guidelines on the Estimation of PM_2.5 for Air Quality Assessment in Hong Kong”, the conservative corrections from RSP concentrations to FSP concentrations are as follows:

· Daily: FSP = 0.75 * RSP  (in µg/m³)

· Annual: FSP = 0.71 * RSP  (in µg/m³)

Prediction of the Cumulative Operational Air Quality Impact

3.5.4.38 The cumulative operational air quality is a combination of the emission impacts contributed from the near field and far field sources (i.e. at local scale and background air quality impact from other concurrent and regional sources).

3.5.4.39 OLM is used for conversion of NO_x to NO₂ based on the O₃ level from PATH directly on an hourly basis. As a conservative approach, the OLM is applied separately to the following groups of emission sources:

· Group A – All open roads

· Group B – All emissions from HKIA

· Group C – All emissions from industrial and marine sources (e.g. chimney emissions from OWTF and marine emissions from NLRTS)

3.5.4.40 In consideration of the number of exceedance allowance of the hourly and daily AQOs (refer to Table 3.1), the pollutant concentrations after the AQOs allowance limits (i.e. the 19th highest 1-hour NO₂ concentrations and 10^th highest 24-hour RSP/ FSP concentrations) are determined at each ASR at 1.5m, 5m, 10m, 13.6m (lowest podium level), 20m, 30m, 40m, 50m, 60m, 70m and 80m above ground. The annual predicted concentrations are also assessed and all predicted levels are then compared with the AQOs.

Without Project Scenario

3.5.4.41 In order to determine the incremental air quality impact from this Project in the assessment year 2026, an additional assessment has been conducted for the without project scenario in the same year. Under this scenario, same methodologies as mentioned above the traffic forecast for without project have been adopted. EMFAC-HK is used to predicted the vehicular emission under the without project scenario and CALINE4 is adopted to assess the vehicular emission impact. Hourly pollutant concentrations from the PATH model is adopted as the background for the cumulative air quality impact.

Prediction of Odour Emission

3.5.4.42 Odour impact from SHWSTW, OWTF and NLRTS and the proposed SPS is assessed by the EPD approved dispersion model AERMOD. Odour emission strengths for SHWSTW and NLRTS are referenced from the approved EIA study for Organic Waste Treatment Facilities Phase 1 (AEIAR-149/2010).

OWTF

3.5.4.43 Source locations and emission strengths, shown in Appendix 3.10, from the variations of Environmental Permit (Application No. VEP-488/2015), approved in February 2015, are adopted for this assessment.

NLRTS

3.5.4.44 Within the NLRTS, the refuse collection vehicles remain enclosed outside the tipping bays. The waste from tipping bays are transferred to a compactor for compacting before being transferred to landfills. Thus vehicle tipping bays and compact area are considered potential odourous sources at NLRTS. Dimensions of the tipping bays and compact area at similar RTS are adopted in the assessment. Based on best available information, deodourizers are installed at NLRTS to reduce odour impact as a general practice. With reference to the approved EIA for “Reprovisioning of FEHD Sai Yee Street Environmental Hygiene Offices-cum-vehicle Depot at Yen Ming Road, West Kowloon Reclamation Area” (AEIAR-177/2013), deodourizng devices at NLRTS is assumed to have an odour removal efficiency of 85%. The source locations and emission rates are summarized in Appendix 3.10.

SHWSTW

3.5.4.45 According to the 2014-15 Sustainability Report from the Drainage Services Department (DSD), installation of covers and deodourizing devices at the Primary Sedimentation Tanks at SHWSTW was completed in 2014. According to the conditions stipulated in the Environmental Permit for Upgrading of Siu Ho Wan Sewege Treatment Plant (EP-076/2000), the deodourizng devices at SHWSTW have a minimum odour removal efficiency of 95%. For the purpose of this EIA, it is assumed that the same odour removal efficiency is achieved.

Proposed Sewage Pumping Station

3.5.4.46 According to the current development plan, a sewage pumping station (SPS), shown in Figure 3.8, is proposed under this Project. The following at-source mitigation measures should be implemented at the proposed sewage pumping stations to control odour emission:

· Potential odour sources should be enclosed;

· Negative pressure should be maintained within the facilities;

· Installation of deodouriser with an odour removal efficiency of at least 95% to control odour emission via ventilation exhaust;

· Exhaust of the deodouriser should be oriented away from sensitive receivers and vertically upwards to avoid direct facing to any sensitive receivers; and

· Maintenance of deodouriser should be regularly conducted to ensure good condition.

3.5.4.47 The dimension of odour sources at the proposed SPS has been estimated by the Project Engineer. The emission rate of the inlet works at SHWSTW (8.79 OU/s/m²) has been adopted as the odour emission rate at the proposed SPS. With reference to the environmental permit for Queen’s Hill Sewage Pumping Station (EP-506/2016), the deodourizng devices at the proposed SPS is assumed to have an odour removal efficiency of 95% as a conservative assumption. The location of odourous sources and odour emission inventory adopted for assessment is summarized in Appendix 3.10.

3.5.4.48 All odour sources are modelled as by “Point” sources. Grid-specific composite meteorological data, including hourly wind speed, wind direction, temperature, relative humidity, mean sea level pressure, cloud fraction and cloud base height, extracted from EPD’s PATH model will be pre-processed by AERMET. The mixing height estimated by AERMET was capped to between 121m and 1667m as per the real meteorological data. For the treatment of calm hours, the wind speed was capped at 1 m/s for wind speed from PATH which are lower than 1 m/s.

3.5.4.49 With reference to the EIAO-TM, the odour criterion is defined as 5 OU units based on an averaging time of 5 seconds. Hence, it is required to convert the predicted odour concentration in 1-hour averaging time from the AERMOD model to 5-second average. Reference is made to the peak-to-mean ratio stated in the “Approved Methods for Modelling and Assessment of Air Pollutants in New South Wales” published by the Department of Environment and Conservation, New South Wales, Australia (NSW Approved Method). In accordance with the NSW Approved Method, the conversion factors for converting 1-hour average to 5-second average concentration are adopted directly as a conservative approach.

3.5.4.50 As stated in the NSW Approved Method, where nearby buildings interfere with the trajectory and growth of the plume, the source is called a wake-affected point source. A point source is wake-affected if stack height is less than or equal to 2.5 times the height of buildings located within a distance of 5L (where L is the lesser of the height or width of the building) from each release point.

3.5.4.51 According to layout from the supporting documents for variations of Environmental Permit (Application No. VEP-488/2015) of OWTF Phase I, the stack of the central pollution units and ammonia stripping plants are 25m and 12m high respectively, while the OWTF Site Office is 11-15.8m high. The deodourizing units at SHWSTW are 6m in height, while the adjacent facilities, including the Centrifuge Building, Screen House, Return Liquor Pumping Station and UV disinfection facility, are 5-10m high. The stacks of deodourizers at NLRTS is located on top of the tipping hall of NLRTS while the stack at the SPS is located on top of the SPS. Thus all odour sources at OWTF, SHWSTW, NLRTS and the proposed SPS are considered wake-affected point sources.

3.5.4.52 The conversion factors for different types of source and stability classes are listed in Table 3.26 below. However, given that the stability class is not included in the AERMOD model, hourly stability class are estimated from the PCRAMMET model, and the hourly emission rate are multiplied by the conversion factor corresponding to the estimated stability class in order to predict the 5-second average odour concentrations.

Table 3.26 Conversion factors for 1-hour to 5-second averaged odour concentration

Stability Class	Point Source (Wake-affected)
A	2.3
B	2.3
C	2.3
D	2.3
E	2.3
F	2.3

3.5.4.53 The overall modelling parameters are summarised in the table below for ease of reference.

Table 3.27 Odour modelling parameters in AERMOD

Parameters	Input
Background Concentration	No
Modelling Mode	Flat Terrain
Land Use	Open water, grassland and urban, specific to each grid Refer to Appendix 3.2 for surface characteristic parameters (e.g. Albedo, Bowen ratio, grid-specific surface roughness)
Meteorological Data	2010 meteorological data adopted in PATH
Anemometer Height	9m

3.5.4.54 The maximum 5-second odour concentrations are determined at each ASR at 1.5m, 5m, 10m, 13.6m (lowest podium level), 20m, 30m, 40m, 50m, 60m, 70m and 80m above ground and compared with the odour criterion to determine compliance.

3.5.5 Prediction and Evaluation of Environmental Impacts

Assessment Results (Criteria Pollutants)

3.5.5.1 The 19^th highest 1-hour and annual NO₂ concentrations, and 10^th highest 24-hour and annual RSP/FSP concentrations predicted under “with Project” scenario are presented in Table 3.28. Detailed results are presented in Appendix 3.11. It can be seen from the table below that all the predicted NO₂/RSP/FSP concentrations are within the respective criteria. In addition, it should also be noted that this operational air quality impact assessment has adopted numbers of conservative assumptions, such as using airport emission in Year 2031 while the assessment year of 2026 is identified.

Table 3.28 Cumulative NO₂, RSP and FSP concentrations (with project scenario)

ASR ID	Worst affected Height above Ground (m)	Pollution Concentration (µg/m^3)
		NO2		RSP			FSP
		19^th Highest 1-hour	Annual	10^th Highest 24-hour		Annual	10^th Highest 24-hour	Annual
Existing ASRs
A1	1.5	153	28	94	35		61	24
A2	1.5	185	32	93	35		61	24
A3	1.5	134	24	80	34		60	24
A4	1.5/5	128	26	79	34		60	24
A5	20	180	37	78	34		58	25
A6	1.5/5/10	180	30	77	33		58	24
Planned ASRs
A101	20	131	25	79	33		58	23
A104	20	131	25	79	33		58	23
A107	20	130	23	79	33		58	23
A108	20	129	23	79	33		58	23
A113	20	129	23	79	33		58	23
A115	20	129	23	79	33		58	23
A118	20	129	23	79	33		58	23
A125	20/40	145	26	80	33		60	24
A128	20/40	146	26	80	33		60	24
A131	20	132	25	79	33		58	23
A135	20	132	25	79	33		58	23
A136	20	129	23	79	33		58	23
A139	20	130	23	79	33		58	23
A142	20	130	23	79	33		58	23
A143	20	130	23	79	33		58	23
A146	20	132	23	79	33		58	23
A149	20	135	23	79	33		58	23
A209	13.6	133	24	78	33		58	23
A211	20	131	24	78	33		58	23
A212	20	131	24	79	33		58	23
A215	20	131	23	78	33		58	23
A219	13.6	136	24	79	33		58	23
A303	20	131	23	78	33		58	23
A307	20	130	23	79	33		58	23
A308	13.6	135	24	78	33		58	23
A310	20	129	23	79	33		58	23
A313	13.6	136	24	79	33		58	23
A318	13.6	136	24	78	33		58	23
A402	20	137	23	79	33		58	23
A404	20	137	23	78	33		58	23
A407	20	136	23	78	33		58	23
A409	20	130	23	78	33		58	23
A412	13.6	135	24	78	33		58	23
A414	20	130	23	78	33		58	23
A417	20/30	134	23	78	33		58	23
A419	20/30	134	24	78	33		58	23
A422	20/30	134	23	78	33		58	23
A501	20/40	138	25	80	33		60	24
A601	20	129	23	79	33		58	23
A701	20/30	131	23	78	33		58	23

3.5.5.2 High pollutant concentrations (e.g. annual NO₂) are generally predicted at existing ASRs located adjacent to the North Lantau Highway and OWTF Phase I, such as A2 (Siu Ho Wan Government Maintenance Depot). Nevertheless, the predicted annual NO₂ concentrations for these existing ASRs are in the range of 24 to 37μg/m³, still complying with the criterion of 40μg/m³. While the ASR A5 (Organic Waste Treatment Facilities) is located in close proximity to industrial chimneys, the predicted annual NO₂ concentration (37μg/m³) also complies with the criterion of 40μg/m³.

3.5.5.3 According to the assessment results, the worst affected levels for existing ASRs and planned ASRs are identified at 1.5m and 13.6m above ground respectively. The pollutant concentrations gradually decrease with increasing height. For example, the predicted annual NO₂ concentration at ASR A2 (Siu Ho Wan Government Maintenance Depot) reduced from 32μg/m³ at 1.5m above ground to 25μg/m³ at 10m above ground. This indicated that the key contributing pollution source is located at ground level, which is the tailpipe emission along open road.

3.5.5.4 Contours of 19^th highest 1-hour and annual NO₂ concentrations, 10^th highest 24-hour and annual RSP/FSP concentrations (with Project Scenario) at the worst affected level for existing and planned ASRs (i.e. 1.5m and 13.6m above ground) are therefore plotted in Figures 3.9 – 3.14. It is also found that there are no exceedances at all air sensitive uses. Hence, no adverse air quality impact on all air sensitive uses is anticipated during the operational phase of this Project. For planned ASRs located above 13.6m above ground, according to the detailed assessment results presented in Appendix 3.11, pollutant concentrations will generally decrease with increasing height above ground. For example, the predicted cumulative annual NO₂ concentrations at A409 (Proposed development atop Siu Ho Wan Depot (Phase 4b)) has reduced from 25μg/m³ at 13.6m above ground to 23μg/m³ and 21μg/m³ at 20m and 50m above ground. Therefore, since the contours plot at 13.6m above ground would represent the worst case scenario for all the planned ASRs and there are no exceedance at all planned ASRs, the planned ASRs at higher level would also comply with the AQOs.

Incremental Air Quality Impact in Future Years

3.5.5.5 Pollutant contributions associated with the Project are generated from its induced traffic. By comparing the assessment results under “with” (i.e. both SHD Topside Development and SHD Replanning Works are included) and “without” (i.e. both SHD Topside Development and SHD Replanning Works are excluded) project scenarios, Project contribution in future year (i.e. Year 2026) could then be quantified. Detailed results under “without” project scenario are presented in Appendix 3.11.

3.5.5.6 According to the assessment results (for both with and without Project Scenarios) as summarised in Tables 3.29 – 3.31, maximum total changes in annual NO₂ on existing and planned ASRs are both less than 1μg/m³, while the maximum total changes in annual RSP / FSP concentrations on both existing and planned ASRs are both less than 2μg/m³ and 1μg/m³ respectively, which are considered relatively small as compared to the AQOs.

3.5.5.7 Maximum total changes in cumulative 19th highest 1-hour NO₂ concentration at existing ASRs and planned ASRs are 2μg/m³ and 1μg/m³ respectively, while the maximum total changes in the 10th highest 24-hour RSP / FSP concentration are 14.5μg/m³ and 2.7μg/m³. Results indicated that the Project would not adversely affect air quality on both existing and planned ASRs during its operational phase.

Table 3.29a Breakdown of mitigated 19^th highest 1-hour NO₂ concentrations under with and without project scenario

ASR ID	19^th Highest 1-hour NO2 Concentrations (µg/m^3)
	With Project						Without Project ^[1]						Change in Concentration (With – without)
	Airport^[2]	Vehicles	Industrial ^[2] [4]	Marine ^[2]	Ambient Background ^[2]	Total	Airport ^[2]	Vehicles	Industrial ^[2] [4]	Marine ^[2]	Ambient Background ^[2]	Total	Vehicles	Total
Existing ASRs
A1	48	67	<1	<1	36	151	48	65	<1	<1	36	149	2	2
A2	90	42	<1	<1	53	185	90	41	<1	<1	53	183	2	2
A3	24	5	<1	<1	105	134	24	4	<1	<1	105	134	<1	<1
A4	<1	11	93	<1	25	128	<1	10	93	<1	25	128	<1	<1
A5	141	12	<1	<1	27	180	141	11	<1	<1	27	179	<1	<1
A6	2	<1	<1	162	15	180	2	<1	<1	162	15	180	<1	<1
Planned ASRs ^[3]
A101	97	18	<1	<1	16	131	97	18	<1	<1	16	131	<1	<1
A104	96	18	<1	<1	16	131	96	18	<1	<1	16	131	<1	<1
A107	96	17	<1	<1	16	130	96	17	<1	<1	16	130	<1	<1
A108	96	17	<1	<1	16	129	96	17	<1	<1	16	129	<1	<1
A113	96	4	<1	<1	29	129	96	4	<1	<1	29	129	<1	<1
A115	96	4	<1	<1	29	129	96	4	<1	<1	29	129	<1	<1
A118	96	4	<1	<1	29	129	96	4	<1	<1	29	129	<1	<1
A125	<1	52	65	<1	28	145	<1	51	65	<1	28	144	<1	<1
A128	<1	32	97	<1	17	146	<1	32	97	<1	17	145	<1	<1
A131	97	19	<1	<1	16	132	97	19	<1	<1	16	132	<1	<1
A135	97	18	<1	<1	16	132	97	18	<1	<1	16	132	<1	<1
A136	96	4	<1	<1	29	129	96	4	<1	<1	29	129	<1	<1
A139	34	7	<1	<1	89	130	34	7	<1	<1	89	130	<1	<1
A142	87	<1	<1	<1	42	130	87	<1	<1	<1	42	130	<1	<1
A143	97	4	<1	<1	29	130	97	4	<1	<1	29	130	<1	<1
A146	36	7	<1	<1	89	132	36	7	<1	<1	89	132	<1	<1
A149	<1	35	36	<1	64	135	<1	34	36	<1	64	134	1	1
A209	90	2	<1	<1	42	133	90	2	<1	<1	42	133	<1	<1
A211	97	18	<1	<1	16	131	97	18	<1	<1	16	131	<1	<1
A212	97	18	<1	<1	16	131	97	18	<1	<1	16	131	<1	<1
A215	34	7	<1	<1	89	131	34	7	<1	<1	89	131	<1	<1
A219	93	1	<1	<1	42	136	93	1	<1	<1	42	136	<1	<1
A303	70	9	<1	<1	52	131	70	9	<1	<1	52	131	<1	<1
A307	94	7	<1	<1	29	130	94	7	<1	<1	29	130	<1	<1
A308	92	2	<1	<1	42	135	92	2	<1	<1	42	135	<1	<1
A310	96	4	<1	<1	29	129	96	4	<1	<1	29	129	<1	<1
A313	93	<1	<1	<1	42	136	93	<1	<1	<1	42	136	<1	<1
A318	93	<1	<1	<1	42	136	93	<1	<1	<1	42	136	<1	<1
A402	86	14	<1	<1	37	137	86	14	<1	<1	37	137	<1	<1
A404	86	14	<1	<1	37	137	86	14	<1	<1	37	137	<1	<1
A407	<1	31	41	<1	64	136	<1	30	41	<1	64	135	1	1
A409	97	4	<1	<1	29	130	97	4	<1	<1	29	130	<1	<1
A412	93	<1	<1	<1	42	135	93	<1	<1	<1	42	135	<1	<1
A414	97	4	<1	<1	29	130	97	4	<1	<1	29	130	<1	<1
A417	39	6	<1	<1	89	134	39	6	<1	<1	89	134	<1	<1
A419	39	6	<1	<1	89	134	39	6	<1	<1	89	134	<1	<1
A422	38	6	<1	<1	89	134	38	6	<1	<1	89	134	<1	<1
A501	83	17	<1	<1	38	138	83	17	<1	<1	38	138	<1	<1
A601	96	4	<1	<1	29	129	96	4	<1	<1	29	129	<1	<1
A701	<1	19	41	<1	71	131	<1	18	41	<1	71	130	<1	<1

Notes:

[1]     Predicted 1-hour NO₂ concentrations at the same hour as those under “With Project “scenario is presented.

[2]     Contribution from Airport, Industrial, Marine and Ambient Background are the same under “With Project “and “Without Project “scenarios.

[3]     Under without project scenario, planned ASRs under this Project will not be existed. Assessment results for these planned ASRs are for indication purpose only.

[4]     Refer to contributions from OWTF Phase 1.

Table 3.29b Breakdown of mitigated annual NO₂ concentrations under with and without project scenario

ASR ID	Annual NO2 Concentrations (µg/m^3)
	With Project						Without Project						Change in Concentration (With – without)
	Airport^[1]	Vehicles	Industrial ^[1] [3]	Marine ^[1]	Ambient Background ^[1]	Total	Airport ^[1]	Vehicles	Industrial ^[1] [3]	Marine ^[1]	Ambient Background ^[1]	Total	Vehicles	Total
Existing ASRs
A1	1.4	7.4	0.3	<0.1	18.6	27.7	1.4	7.2	0.3	<0.1	18.6	27.4	0.2	0.2
A2	1.8	11.7	0.4	<0.1	17.7	31.6	1.8	11.3	0.4	<0.1	17.7	31.2	0.4	0.4
A3	1.2	3.6	0.9	<0.1	18.6	24.4	1.2	3.5	0.9	<0.1	18.6	24.2	0.1	0.1
A4	1.1	2.0	4.0	<0.1	18.6	25.7	1.1	1.9	4.0	<0.1	18.6	25.6	0.1	0.1
A5	1.6	2.7	12.6	<0.1	19.8	36.8	1.6	2.6	12.6	<0.1	19.8	36.7	0.1	0.1
A6	1.7	5.7	2.4	0.9	19.8	30.4	1.7	5.4	2.4	0.9	19.8	30.1	0.2	0.2
Planned ASRs [2]
A101	2.0	4.8	0.2	<0.1	17.7	24.7	2.0	4.7	0.2	<0.1	17.7	24.6	0.1	0.1
A104	1.9	4.7	0.3	<0.1	17.7	24.5	1.9	4.5	0.3	<0.1	17.7	24.4	0.1	0.1
A107	1.9	3.5	0.3	<0.1	17.7	23.4	1.9	3.4	0.3	<0.1	17.7	23.2	0.1	0.1
A108	1.9	3.3	0.3	<0.1	17.7	23.1	1.9	3.1	0.3	<0.1	17.7	23.0	0.1	0.1
A113	1.9	2.8	0.3	<0.1	17.7	22.7	1.9	2.7	0.3	<0.1	17.7	22.6	0.1	0.1
A115	1.9	2.8	0.3	<0.1	17.7	22.7	1.9	2.7	0.3	<0.1	17.7	22.5	0.1	0.1
A118	1.8	3.0	0.3	<0.1	17.7	22.9	1.8	2.9	0.3	<0.1	17.7	22.7	0.1	0.1
A125	2.3	5.2	0.6	<0.1	18.2	26.4	2.3	5.0	0.6	<0.1	18.2	26.2	0.2	0.2
A128	2.3	5.3	0.6	<0.1	18.2	26.5	2.3	5.1	0.6	<0.1	18.2	26.3	0.2	0.2
A131	2.0	5.1	0.2	<0.1	17.7	25.1	2.0	5.0	0.2	<0.1	17.7	24.9	0.2	0.2
A135	2.0	5.0	0.2	<0.1	17.7	24.9	2.0	4.9	0.2	<0.1	17.7	24.8	0.2	0.2
A136	1.8	3.0	0.3	<0.1	17.7	22.8	1.8	2.8	0.3	<0.1	17.7	22.7	0.1	0.1
A139	1.8	2.7	0.4	<0.1	17.7	22.6	1.8	2.6	0.4	<0.1	17.7	22.5	0.1	0.1
A142	1.8	3.1	0.4	<0.1	17.7	22.9	1.8	2.9	0.4	<0.1	17.7	22.8	0.1	0.1
A143	1.8	2.9	0.4	<0.1	17.7	22.8	1.8	2.8	0.4	<0.1	17.7	22.7	0.1	0.1
A146	1.8	2.6	0.4	<0.1	17.7	22.5	1.8	2.5	0.4	<0.1	17.7	22.4	0.1	0.1
A149	1.7	2.7	0.5	<0.1	17.7	22.6	1.7	2.6	0.5	<0.1	17.7	22.5	0.1	0.1
A209	2.0	3.8	0.2	<0.1	17.7	23.8	2.0	3.6	0.2	<0.1	17.7	23.6	0.2	0.2
A211	2.0	4.1	0.2	<0.1	17.7	24.0	2.0	3.9	0.2	<0.1	17.7	23.8	0.2	0.2
A212	2.0	4.2	0.3	<0.1	17.7	24.1	2.0	4.0	0.3	<0.1	17.7	23.9	0.2	0.2
A215	1.9	3.4	0.3	<0.1	17.7	23.3	1.9	3.3	0.3	<0.1	17.7	23.2	0.1	0.1
A219	2.0	3.8	0.2	<0.1	17.7	23.7	2.0	3.6	0.2	<0.1	17.7	23.6	0.2	0.2
A303	1.9	3.5	0.3	<0.1	17.7	23.4	1.9	3.3	0.3	<0.1	17.7	23.2	0.2	0.2
A307	1.8	3.5	0.4	<0.1	17.7	23.3	1.8	3.3	0.4	<0.1	17.7	23.2	0.2	0.2
A308	1.8	3.8	0.3	<0.1	17.7	23.7	1.8	3.7	0.3	<0.1	17.7	23.6	0.2	0.2
A310	1.9	3.6	0.3	<0.1	17.7	23.5	1.9	3.4	0.3	<0.1	17.7	23.3	0.2	0.2
A313	1.9	3.8	0.3	<0.1	17.7	23.7	1.9	3.6	0.3	<0.1	17.7	23.6	0.2	0.2
A318	1.9	3.8	0.3	<0.1	17.7	23.7	1.9	3.6	0.3	<0.1	17.7	23.5	0.2	0.2
A402	1.7	2.6	0.5	<0.1	17.7	22.6	1.7	2.5	0.5	<0.1	17.7	22.4	0.1	0.1
A404	1.7	2.7	0.5	<0.1	17.7	22.6	1.7	2.6	0.5	<0.1	17.7	22.5	0.1	0.1
A407	1.7	2.8	0.6	<0.1	17.7	22.7	1.7	2.6	0.6	<0.1	17.7	22.6	0.1	0.1
A409	1.8	3.5	0.4	<0.1	17.7	23.4	1.8	3.4	0.4	<0.1	17.7	23.3	0.2	0.2
A412	1.8	3.9	0.4	<0.1	17.7	23.8	1.8	3.7	0.4	<0.1	17.7	23.7	0.2	0.2
A414	1.8	3.4	0.4	<0.1	17.7	23.3	1.8	3.2	0.4	<0.1	17.7	23.1	0.2	0.2
A417	1.7	3.5	0.5	<0.1	17.7	23.5	1.7	3.4	0.5	<0.1	17.7	23.3	0.2	0.2
A419	1.7	3.6	0.5	<0.1	17.7	23.5	1.7	3.4	0.5	<0.1	17.7	23.4	0.2	0.2
A422	1.7	3.3	0.6	<0.1	17.7	23.3	1.7	3.2	0.6	<0.1	17.7	23.2	0.1	0.1
A501	2.3	4.4	0.5	<0.1	18.2	25.4	2.3	4.2	0.5	<0.1	18.2	25.2	0.2	0.2
A601	1.9	3.5	0.3	<0.1	17.7	23.3	1.9	3.3	0.3	<0.1	17.7	23.2	0.2	0.2
A701	1.7	3.3	0.5	<0.1	17.7	23.2	1.7	3.1	0.5	<0.1	17.7	23.0	0.1	0.1

Note:

[1]     Contribution from Airport, Industrial, Marine and Ambient Background are the same under “With Project “and “Without Project “scenarios.

[2]     Under without project scenario, planned ASRs under this Project will not be existed. Assessment results for these planned ASRs are for indication purpose only.

[3]     Refer to contributions from OWTF Phase 1.

Table 3.30a Breakdown of mitigated 10^th highest 24-hour RSP concentrations under with and without project scenario

ASR ID	10^th highest 24-hour RSP Concentrations (µg/m^3)
	With Project							Without Project ^[1]						Change in Concentration (With – without)
	Airport ^[2]	Vehicles	Industrial ^[2][4]	Marine ^[2]	Dust from SHO and SHD Replanning Works	Ambient Background ^[2]	Total	Airport ^[2]	Vehicles	Industrial  ^[2] [4]	Marine ^[2]	Ambient Background ^[2]	Total	Vehicles	Dust from SHO and SHD Replanning Works	Total
Existing ASRs
A1	<0.1	0.4	<0.1	<0.1	1.0	92.6	94.1	<0.1	0.4	<0.1	<0.1	92.6	93.1	<0.1	1.0	1.0
A2	<0.1	1.0	0.1	<0.1	14.5	77.4	93.1	<0.1	1.0	0.1	<0.1	77.4	78.6	<0.1	14.5	14.5
A3	<0.1	0.2	0.7	<0.1	<0.1	78.7	79.6	<0.1	0.2	0.7	<0.1	78.7	79.6	<0.1	<0.1	<0.1
A4	<0.1	<0.1	0.7	<0.1	<0.1	78.7	79.4	<0.1	<0.1	0.7	<0.1	78.7	79.4	<0.1	<0.1	<0.1
A5	<0.1	0.3	0.6	<0.1	<0.1	76.7	77.8	<0.1	0.2	0.6	<0.1	76.7	77.6	0.2	<0.1	0.2
A6	<0.1	0.4	<0.1	<0.1	<0.1	76.7	77.3	<0.1	0.2	<0.1	<0.1	76.7	77.0	0.2	<0.1	0.3
Planned ASRs ^[3]
A101	<0.1	0.1	<0.1	<0.1	3.6	75.1	79.0	<0.1	0.1	<0.1	<0.1	75.1	75.3	<0.1	3.6	3.6
A104	<0.1	<0.1	<0.1	<0.1	1.5	77.4	79.0	<0.1	0.1	<0.1	<0.1	77.4	77.5	<0.1	1.5	1.6
A107	<0.1	<0.1	<0.1	<0.1	1.6	77.4	79.1	<0.1	0.1	<0.1	<0.1	77.4	77.5	<0.1	1.6	1.6
A108	<0.1	<0.1	<0.1	<0.1	1.6	77.4	79.1	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	1.6	1.6
A113	<0.1	<0.1	<0.1	<0.1	1.7	77.4	79.2	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	1.7	1.7
A115	<0.1	<0.1	<0.1	<0.1	4.0	75.1	79.3	<0.1	<0.1	<0.1	<0.1	75.1	75.3	<0.1	4.0	4.0
A118	<0.1	<0.1	<0.1	<0.1	4.1	75.1	79.4	<0.1	<0.1	<0.1	<0.1	75.1	75.3	<0.1	4.1	4.1
A125	<0.1	<0.1	0.1	<0.1	1.0	78.6	79.8	<0.1	<0.1	0.1	<0.1	78.6	78.8	<0.1	1.0	1.0
A128	<0.1	<0.1	0.1	<0.1	1.4	78.6	80.1	<0.1	<0.1	0.1	<0.1	78.6	78.8	<0.1	1.4	1.4
A131	<0.1	<0.1	<0.1	<0.1	1.5	77.4	79.0	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	1.5	1.5
A135	<0.1	0.1	<0.1	<0.1	3.7	75.1	79.0	<0.1	0.1	<0.1	<0.1	75.1	75.3	<0.1	3.7	3.7
A136	<0.1	<0.1	<0.1	<0.1	3.9	75.1	79.2	<0.1	<0.1	<0.1	<0.1	75.1	75.3	<0.1	3.9	3.9
A139	<0.1	<0.1	<0.1	<0.1	1.7	77.4	79.2	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	1.7	1.7
A142	<0.1	<0.1	0.1	<0.1	1.7	77.4	79.2	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	1.7	1.7
A143	<0.1	<0.1	0.1	<0.1	1.4	77.4	79.0	<0.1	<0.1	0.1	<0.1	77.4	77.5	<0.1	1.4	1.4
A146	<0.1	<0.1	0.1	<0.1	1.2	77.4	78.7	<0.1	<0.1	0.1	<0.1	77.4	77.6	<0.1	1.2	1.2
A149	<0.1	0.1	<0.1	<0.1	3.3	75.1	78.6	<0.1	<0.1	<0.1	<0.1	75.1	75.3	<0.1	3.3	3.3
A209	<0.1	<0.1	<0.1	<0.1	0.7	77.4	78.2	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	0.7	0.7
A211	<0.1	<0.1	<0.1	<0.1	0.9	77.4	78.4	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	0.9	0.9
A212	<0.1	<0.1	<0.1	<0.1	1.1	77.4	78.6	<0.1	0.1	<0.1	<0.1	77.4	77.5	<0.1	1.1	1.1
A215	<0.1	<0.1	<0.1	<0.1	0.9	77.4	78.4	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	0.9	0.9
A219	<0.1	<0.1	<0.1	<0.1	1.1	77.4	78.6	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	1.1	1.1
A303	<0.1	<0.1	<0.1	<0.1	0.7	77.4	78.2	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	0.7	0.7
A307	<0.1	<0.1	0.1	<0.1	1.1	77.4	78.6	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	1.1	1.1
A308	<0.1	<0.1	0.1	<0.1	0.7	77.4	78.2	<0.1	<0.1	0.1	<0.1	77.4	77.5	<0.1	0.7	0.7
A310	<0.1	<0.1	<0.1	<0.1	1.0	77.4	78.5	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	1.0	1.0
A313	<0.1	<0.1	<0.1	<0.1	1.1	77.4	78.6	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	1.1	1.1
A318	<0.1	<0.1	<0.1	<0.1	0.6	77.4	78.1	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	0.6	0.6
A402	<0.1	0.1	<0.1	<0.1	3.4	75.1	78.7	<0.1	0.1	<0.1	<0.1	75.1	75.3	<0.1	3.4	3.4
A404	<0.1	0.1	<0.1	<0.1	3.0	75.1	78.3	<0.1	0.1	<0.1	<0.1	75.1	75.3	<0.1	3.0	3.0
A407	<0.1	<0.1	0.2	<0.1	<0.1	77.4	77.6	<0.1	<0.1	0.2	<0.1	77.4	77.6	<0.1	<0.1	<0.1
A409	<0.1	<0.1	0.1	<0.1	0.6	77.4	78.1	<0.1	<0.1	0.1	<0.1	77.4	77.5	<0.1	0.6	0.6
A412	<0.1	<0.1	0.1	<0.1	0.2	77.4	77.7	<0.1	<0.1	0.1	<0.1	77.4	77.5	<0.1	0.2	0.2
A414	<0.1	<0.1	0.1	<0.1	0.6	77.4	78.1	<0.1	<0.1	0.1	<0.1	77.4	77.5	<0.1	0.6	0.6
A417	<0.1	<0.1	0.1	<0.1	0.1	77.4	77.7	<0.1	<0.1	0.1	<0.1	77.4	77.6	<0.1	0.1	0.1
A419	<0.1	<0.1	0.2	<0.1	<0.1	77.4	77.6	<0.1	<0.1	0.2	<0.1	77.4	77.6	<0.1	<0.1	0.1
A422	<0.1	<0.1	0.2	<0.1	<0.1	77.4	77.6	<0.1	<0.1	0.2	<0.1	77.4	77.6	<0.1	<0.1	0.1
A501	<0.1	0.2	<0.1	<0.1	0.1	79.4	79.7	<0.1	0.2	<0.1	<0.1	79.4	79.6	<0.1	0.1	0.1
A601	<0.1	<0.1	<0.1	<0.1	1.2	77.4	78.8	<0.1	<0.1	<0.1	<0.1	77.4	77.5	<0.1	1.3	1.3
A701	<0.1	<0.1	<0.1	<0.1	2.8	75.1	78.1	<0.1	<0.1	<0.1	<0.1	75.1	75.3	<0.1	2.8	2.8

Notes:

[1]     Predicted 24-hour RSP concentrations at the same day as those under “With Project “scenario is presented.

[2]     Contribution from Airport, Industrial, Marine and Ambient Background are the same under “With Project “and “Without Project “scenarios.

[3]     Under without project scenario, planned ASRs under this Project will not be existed. Assessment results for these planned ASRs are for indication purpose only.

[4]     Refer to contributions from OWTF Phase 1.

Table 3.30b Breakdown of mitigated annual RSP concentrations under with and without project scenario

ASR ID	Annual RSP Concentrations (µg/m^3)
	With Project							Without Project ^[1]						Change in Concentration (With – without)
	Airport ^[1]	Vehicles	Industrial ^[1][3]	Marine ^[1]	Dust from SHO and SHD Replanning Works	Ambient Background ^[1]	Total	Airport ^[1]	Vehicles	Industrial  ^[1] [3]	Marine ^[1]	Ambient Background ^[1]	Total	Vehicles	Dust from SHO and SHD Replanning Works	Total
Existing ASRs
A1	<0.1	0.3	<0.1	<0.1	1.1	33.8	35.2	0.1	0.3	<0.1	<0.1	33.8	34.2	<0.1	1.1	1.1
A2	0.1	0.5	<0.1	<0.1	1.4	32.4	34.5	0.1	0.5	<0.1	<0.1	32.4	33.1	<0.1	1.4	1.4
A3	<0.1	0.2	0.1	<0.1	<0.1	33.8	34.1	0.1	0.2	0.1	<0.1	33.8	34.1	<0.1	<0.1	<0.1
A4	<0.1	<0.1	0.3	<0.1	<0.1	33.8	34.2	0.1	0.1	0.3	<0.1	33.8	34.2	<0.1	<0.1	<0.1
A5	<0.1	0.2	1.1	<0.1	<0.1	32.8	34.1	0.0	0.1	1.1	<0.1	32.8	34.0	<0.1	<0.1	<0.1
A6	<0.1	0.3	0.2	<0.1	<0.1	32.8	33.4	0.0	0.2	0.2	<0.1	32.8	33.4	<0.1	<0.1	0.1
Planned ASRs ^[2]
A101	0.1	0.2	<0.1	<0.1	0.1	32.4	32.9	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.1	0.2
A104	0.1	0.2	<0.1	<0.1	0.1	32.4	32.8	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.1	0.1
A107	0.1	0.2	<0.1	<0.1	0.1	32.4	32.8	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.1	0.1
A108	0.1	0.1	<0.1	<0.1	0.1	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.1	0.1
A113	0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.2	0.2
A115	0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.2	0.2
A118	0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.2	0.2
A125	0.1	0.2	<0.1	<0.1	0.1	32.9	33.4	0.1	0.2	<0.1	<0.1	32.9	33.3	<0.1	0.1	0.1
A128	0.1	0.2	<0.1	<0.1	0.1	32.9	33.4	0.1	0.2	<0.1	<0.1	32.9	33.3	<0.1	0.1	0.1
A131	0.1	0.2	<0.1	<0.1	0.1	32.4	32.9	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.1	0.1
A135	0.1	0.2	<0.1	<0.1	0.2	32.4	32.9	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.2	0.2
A136	0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.2	0.2
A139	0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.2	0.2
A142	<0.1	0.1	<0.1	<0.1	0.1	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.1	0.1
A143	<0.1	0.1	<0.1	<0.1	0.1	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.1	0.1
A146	<0.1	0.1	<0.1	<0.1	0.1	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.1	0.1
A149	<0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.2	0.2
A209	0.1	0.2	<0.1	<0.1	0.4	32.4	33.1	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.4	0.4
A211	0.1	0.2	<0.1	<0.1	0.2	32.4	32.8	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.2	0.2
A212	0.1	0.2	<0.1	<0.1	0.1	32.4	32.8	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.1	0.1
A215	0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.7	<0.1	0.2	0.2
A219	0.1	0.2	<0.1	<0.1	0.3	32.4	33.0	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.3	0.3
A303	0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.7	<0.1	0.2	0.2
A307	0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.7	<0.1	0.2	0.2
A308	0.1	0.2	<0.1	<0.1	0.3	32.4	33.0	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.3	0.3
A310	0.1	0.2	<0.1	<0.1	0.2	32.4	32.8	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.2	0.2
A313	0.1	0.2	<0.1	<0.1	0.4	32.4	33.1	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.4	0.4
A318	0.1	0.2	<0.1	<0.1	0.4	32.4	33.1	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.4	0.4
A402	<0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.2	0.2
A404	<0.1	0.1	<0.1	<0.1	0.1	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.1	0.1
A407	<0.1	0.1	<0.1	<0.1	0.1	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.6	<0.1	0.1	0.1
A409	<0.1	0.2	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.7	<0.1	0.2	0.2
A412	0.1	0.2	<0.1	<0.1	0.4	32.4	33.1	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.4	0.4
A414	<0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.7	<0.1	0.2	0.2
A417	<0.1	0.2	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.7	<0.1	0.1	0.2
A419	<0.1	0.2	<0.1	<0.1	0.1	32.4	32.8	0.1	0.2	<0.1	<0.1	32.4	32.7	<0.1	0.1	0.1
A422	<0.1	0.1	<0.1	<0.1	<0.1	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.7	<0.1	<0.1	<0.1
A501	0.1	0.2	<0.1	<0.1	0.1	32.9	33.4	0.1	0.2	<0.1	<0.1	32.9	33.2	<0.1	0.1	0.1
A601	0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.7	<0.1	0.2	0.2
A701	<0.1	0.1	<0.1	<0.1	0.2	32.4	32.8	0.1	0.1	<0.1	<0.1	32.4	32.7	<0.1	0.2	0.2

Notes:

[1]     Contribution from Airport, Industrial, Marine and Ambient Background are the same under “With Project “and “Without Project “scenarios.

[2]     Under without project scenario, planned ASRs under this Project will not be existed. Assessment results for these planned ASRs are for indication purpose only.

[3]     Refer to contributions from OWTF Phase 1.

Table 3.31a Breakdown of mitigated 10^th highest 24-hour FSP concentrations under with and without project scenario

ASR ID	10^th highest 24-hour FSP Concentrations (µg/m^3)
	With Project							Without Project ^[1]						Change in Concentration (With – without)
	Airport ^[2]	Vehicles	Industrial ^[2] [4]	Marine ^[2]	Dust from SHO and SHD Replanning Works	Ambient Background ^[2]	Total	Airport ^[2]	Vehicles	Industrial ^[2] [4]	Marine ^[2]	Ambient Background ^[2]	Total	Vehicles	Dust from SHO and SHD Replanning Works	Total
Existing ASRs
A1	<0.1	0.6	<0.1	<0.1	1.2	59.2	61.0	<0.1	0.6	<0.1	<0.1	59.2	59.9	<0.1	1.2	1.2
A2	<0.1	1.4	<0.1	<0.1	2.7	56.3	60.5	<0.1	1.4	<0.1	<0.1	56.3	57.8	<0.1	2.7	2.7
A3	<0.1	0.2	0.7	<0.1	<0.1	59.1	59.9	<0.1	0.2	0.7	<0.1	59.1	59.9	<0.1	<0.1	<0.1
A4	<0.1	<0.1	0.7	<0.1	<0.1	59.0	59.7	<0.1	<0.1	0.7	<0.1	59.0	59.7	<0.1	<0.1	<0.1
A5	<0.1	0.2	<0.1	<0.1	<0.1	58.3	58.5	<0.1	0.2	<0.1	<0.1	58.3	58.5	<0.1	<0.1	<0.1
A6	<0.1	0.2	<0.1	<0.1	<0.1	57.5	57.9	<0.1	0.2	<0.1	<0.1	57.5	57.8	<0.1	<0.1	<0.1
Planned ASRs ^[3]
A101	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.3	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A104	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A107	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A108	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A113	<0.1	<0.1	<0.1	<0.1	0.3	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.3	0.3
A115	<0.1	<0.1	<0.1	<0.1	0.3	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.3	0.3
A118	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A125	0.1	0.1	<0.1	<0.1	0.4	58.9	59.5	0.1	0.1	<0.1	<0.1	58.9	59.2	<0.1	0.4	0.4
A128	0.1	0.1	<0.1	<0.1	0.5	58.9	59.7	0.1	0.1	<0.1	<0.1	58.9	59.2	<0.1	0.5	0.5
A131	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.1	<0.1	0.2	0.2
A135	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.1	<0.1	0.2	0.2
A136	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A139	<0.1	<0.1	<0.1	<0.1	0.3	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.3	0.3
A142	<0.1	<0.1	0.1	<0.1	0.3	58.0	58.4	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	0.3	0.3
A143	<0.1	<0.1	0.1	<0.1	0.2	58.0	58.4	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A146	<0.1	<0.1	0.1	<0.1	0.2	58.0	58.4	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A149	<0.1	<0.1	0.1	<0.1	0.1	58.0	58.3	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	0.1	0.1
A209	<0.1	<0.1	<0.1	<0.1	0.1	58.0	58.2	<0.1	<0.1	<0.1	<0.1	58.0	58.1	<0.1	0.1	0.1
A211	<0.1	<0.1	<0.1	<0.1	0.1	58.0	58.3	<0.1	<0.1	<0.1	<0.1	58.0	58.1	<0.1	0.1	0.1
A212	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.3	<0.1	<0.1	<0.1	<0.1	58.0	58.1	<0.1	0.2	0.2
A215	<0.1	<0.1	<0.1	<0.1	0.1	58.0	58.3	<0.1	<0.1	<0.1	<0.1	58.0	58.1	<0.1	0.1	0.1
A219	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.3	<0.1	<0.1	<0.1	<0.1	58.0	58.1	<0.1	0.2	0.2
A303	<0.1	<0.1	<0.1	<0.1	0.1	58.0	58.3	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.1	0.1
A307	<0.1	<0.1	0.1	<0.1	0.2	58.0	58.3	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A308	<0.1	<0.1	0.1	<0.1	0.1	58.0	58.3	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	0.1	0.1
A310	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.3	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A313	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.3	<0.1	<0.1	<0.1	<0.1	58.0	58.1	<0.1	0.2	0.2
A318	<0.1	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	<0.1	<0.1
A402	<0.1	<0.1	0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	<0.1	<0.1
A404	<0.1	<0.1	0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	<0.1	<0.1
A407	<0.1	<0.1	0.2	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	58.0	58.2	<0.1	<0.1	<0.1
A409	<0.1	<0.1	0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	<0.1	<0.1
A412	<0.1	<0.1	0.1	<0.1	<0.1	58.0	58.2	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	<0.1	<0.1
A414	<0.1	<0.1	0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	<0.1	<0.1
A417	<0.1	<0.1	0.1	<0.1	<0.1	58.0	58.2	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	<0.1	<0.1
A419	<0.1	<0.1	0.2	<0.1	<0.1	58.0	58.2	<0.1	<0.1	0.2	<0.1	58.0	58.2	<0.1	<0.1	<0.1
A422	<0.1	<0.1	0.2	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.2	<0.1	58.0	58.2	<0.1	<0.1	<0.1
A501	<0.1	<0.1	0.6	<0.1	<0.1	58.9	59.6	<0.1	<0.1	0.6	<0.1	58.9	59.5	<0.1	<0.1	<0.1
A601	<0.1	<0.1	<0.1	<0.1	0.2	58.0	58.4	<0.1	<0.1	<0.1	<0.1	58.0	58.2	<0.1	0.2	0.2
A701	<0.1	<0.1	0.1	<0.1	<0.1	58.0	58.3	<0.1	<0.1	0.1	<0.1	58.0	58.2	<0.1	<0.1	<0.1

Notes:                                                                                                      

[1]     Predicted 24-hour RSP concentrations at the same day as those under “With Project “scenario is presented.

[2]     Contribution from Airport, Industrial, Marine and Ambient Background are the same under “With Project “and “Without Project “scenarios.

[3]     Under without project scenario, planned ASRs under this Project will not be existed. Assessment results for these planned ASRs are for indication purpose only.

[4]     Refer to contributions from OWTF Phase 1

Table 3.31b Breakdown of mitigated annual FSP concentrations under with and without project scenario

ASR ID	Annual FSP Concentrations (µg/m^3)
	With Project							Without Project						Change in Concentration (With – without)
	Airport ^[1]	Vehicles	Industrial  ^[1] [3]	Marine ^[1]	Dust from SHO and SHD Replanning Works	Ambient Background ^[1]	Total	Airport ^[1]	Vehicles	Industrial ^[1] [3]	Marine ^[1]	Ambient Background ^[1]	Total	Vehicles	Dust from SHO and SHD Replanning Works	Total
Existing ASRs
A1	<0.1	0.3	<0.1	<0.1	0.2	24.0	24.5	<0.1	0.3	<0.1	<0.1	24.0	24.3	<0.1	0.2	0.2
A2	<0.1	0.5	<0.1	<0.1	0.2	23.0	23.8	<0.1	0.5	<0.1	<0.1	23.0	23.6	<0.1	0.2	0.2
A3	<0.1	0.1	0.1	<0.1	<0.1	24.0	24.3	<0.1	0.1	0.1	<0.1	24.0	24.2	<0.1	<0.1	<0.1
A4	<0.1	<0.1	0.3	<0.1	<0.1	24.0	24.3	<0.1	<0.1	0.3	<0.1	24.0	24.3	<0.1	<0.1	<0.1
A5	<0.1	0.1	1.1	<0.1	<0.1	23.3	24.5	<0.1	0.1	1.1	<0.1	23.3	24.5	<0.1	<0.1	<0.1
A6	<0.1	0.2	0.2	<0.1	<0.1	23.3	23.8	<0.1	0.2	0.2	<0.1	23.3	23.8	<0.1	<0.1	<0.1
Planned ASRs  ^[2]
A101	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A104	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A107	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A108	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A113	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A115	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A118	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A125	<0.1	0.2	0.1	<0.1	<0.1	23.3	23.7	<0.1	0.2	0.1	<0.1	23.3	23.7	<0.1	<0.1	<0.1
A128	<0.1	0.2	0.1	<0.1	<0.1	23.3	23.7	<0.1	0.2	0.1	<0.1	23.3	23.7	<0.1	<0.1	<0.1
A131	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A135	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A136	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A139	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A142	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A143	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A146	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A149	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A209	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A211	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A212	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A215	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A219	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A303	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A307	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A308	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A310	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A313	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A318	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A402	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A404	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A407	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A409	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.3	<0.1	<0.1	<0.1
A412	<0.1	0.2	<0.1	<0.1	<0.1	23.0	23.3	<0.1	0.2	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A414	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A417	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A419	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A422	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A501	<0.1	0.1	0.1	<0.1	<0.1	23.3	23.6	<0.1	0.1	0.1	<0.1	23.3	23.6	<0.1	<0.1	<0.1
A601	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1
A701	<0.1	0.1	<0.1	<0.1	<0.1	23.0	23.2	<0.1	0.1	<0.1	<0.1	23.0	23.2	<0.1	<0.1	<0.1

Notes:

[1]     Contribution from Airport, Industrial, Marine and Ambient Background are the same under “With Project “and “Without Project “scenarios.

[2]     Under without project scenario, planned ASRs under this Project will not be existed. Assessment results for these planned ASRs are for indication purpose only.

[3]     Refer to contributions from OWTF Phase 1.

Odour Assessment Results

3.5.5.8 The maximum 5-second odour concentrations are presented in Table 3.33. Detailed results are presented in Appendix 3.12. As the proposed SPS is the only odour source proposed under this Project, the incremental odour impact is entirely attributed to the SPS.

Table 3.33 Cumulative odour concentrations

ASR ID	Worst affected Height above Ground (m)	Maximum 5-second Odour Concentration (OU)
		With Project	Without Project	Difference
Existing ASRs
A1	10	1.5	1.5	<0.1
A2	1.5	0.9	0.9	<0.1
A3	5	2.9	2.9	<0.1
A4	5	1.0	1.0	<0.1
A5	10	3.7	3.7	<0.1
A6	1.5	1.7	1.7	<0.1
Planned ASRs
A101	50	0.6	0.6	<0.1
A104	50	0.6	0.6	<0.1
A107	50	0.6	0.6	<0.1
A108	50	0.7	0.7	<0.1
A113	50	0.7	0.7	<0.1
A115	50	0.7	0.7	<0.1
A118	50	0.8	0.8	<0.1
A125	40	1.6	1.6	<0.1
A128	40	1.6	1.6	<0.1
A131	50	0.5	0.5	<0.1
A135	50	0.6	0.6	<0.1
A136	50	0.9	0.9	<0.1
A139	50	0.9	0.9	<0.1
A142	50	1.0	1.0	<0.1
A143	50	1.0	1.0	<0.1
A146	50	1.1	1.1	<0.1
A149	50	1.1	1.1	<0.1
A209	50	0.5	0.5	<0.1
A211	50	0.6	0.6	<0.1
A212	50	0.7	0.7	<0.1
A215	50	0.6	0.6	<0.1
A219	50	0.6	0.6	<0.1
A303	50	0.8	0.8	<0.1
A307	50	1.0	1.0	<0.1
A308	50	0.9	0.9	<0.1
A310	50	0.7	0.7	<0.1
A313	50	0.7	0.7	<0.1
A318	50	0.8	0.8	<0.1
A402	50	1.2	1.2	<0.1
A404	50	1.3	1.3	<0.1
A407	50	1.4	1.4	<0.1
A409	50	0.9	0.9	<0.1
A412	13.6	1.1	1.1	<0.1
A414	20	1.2	1.2	<0.1
A417	20	1.2	1.2	<0.1
A419	20	1.4	1.4	<0.1
A422	20	1.7	1.7	<0.1
A501	40	1.3	1.3	<0.1
A601	50	0.8	0.8	<0.1
A701	50	1.3	1.3	<0.1

Note:

Under without project scenario, planned ASRs under this Project will not be existed. Assessment results for these planned ASRs are for indication purpose only.

3.5.5.9 It can be seen from the table above that all the predicted odour concentrations at existing and planned ASRs within the proposed development comply with the odour criterion. The incremental odour impact due to the proposed SPS at the existing ASRs is less than 0.1 OU. Thus odour impact due to the SPS is anticipated to be insignificant.

3.5.5.10 Table 3.33 shows that the highest odour concentrations at existing ASRs is observed at 5m and 10m above ground. Odour concentrations are generally the highest at 13.6m and 50m above ground for planned ASRs. Thus contours of highest 5-second odour concentrations at these worst affected levels above the podium level (i.e. 5m, 10m, 13.6m and 50m above ground) are therefore plotted in Figure 3.15. It is also found that there are no exceedances at all air sensitive uses within the proposed development. In addition, no existing air sensitive uses are located within the area of exceedance at the respective levels (i.e. 5m, 13.6 and 50m above ground). Hence, no adverse odour impact on all existing and planned ASRs is anticipated during the operational phase of this Project.

3.5.5.11 As discussed in Section 3.5.4, at-source mitigation measures will be implemented at the proposed sewage pumping stations to control odour emission. Thus it is anticipated that odour contribution from the Project is insignificant.

3.5.6 Mitigation Measures

3.5.6.1 All the predicted criteria pollutant concentrations are in compliance with the AQO. Hence, no mitigation measures are required.

3.5.6.2 The predicted odour concentrations are in compliance with the odour criterion. Nevertheless, as discussed in Section 3.5.4, the following at-source mitigation measures should be implemented at the proposed sewage pumping stations to control odour emission:

· Potential odour sources should be enclosed;

· Negative pressure should be maintained within the facilities;

· Installation of deodouriser with an odour removal efficiency of at least 95% to control odour emission via ventilation exhaust;

· Exhaust of the deodouriser should be oriented away from sensitive receivers and vertically upwards to avoid direct facing to any sensitive receivers; and

· Maintenance of deodouriser should be regularly conducted to ensure good condition.

3.5.7 Residual Environmental Impacts

3.5.7.1 According to the operational air quality assessment result, it is indicated that adverse residual air quality impact during the operational phase is not anticipated.

3.6 Air Quality Impact Assessment Conducted by SHO and SHD Replanning Works

3.6.1.1 As discussed in Section 1.3, the latest implementation strategy has recommended the following items in EIA Study Brief ESB-296/2016 will be separately implemented by the SHO and SHD Replanning Works project which will be addressed in Railway EIA.

· Railway depot replanning works within the existing site boundary;

· Podium deck and property enabling works for the topside development;

· A new SHO and associated track works, as well as local access roads and emergency vehicular access (EVA); and

· Provision of the sewerage network with sewage pumping station to cater sewage generated by SHO and SHD Replanning Works.

3.6.1.2 According to Section 3.5.4, construction activities associated with Stages 2 to 4 of SHD Replanning Works will be carried out during the operational phase of the Project (2026-2034). As SHD Topside Development will commence its population intake in the Year 2026, the assessment of cumulative construction dust impact arising from Stages 2 to 4 SHD Replanning Works on planned ASRs in Topside Development has been conducted by both the SHD Topside Development and Railway EIA. The Railway EIA has also recommended similar mitigation measures as described in Section 3.4.6 to alleviate dust impacts. The assessment results, shown in Appendix 3.11a, have been incorporated to operational phase assessment.

3.7 Conclusion

3.7.1 Construction Phase

3.7.1.1 Potential construction dust impact would be generated from foundation works for SPS, utility construction and road widening, etc. during construction phase. Quantitative construction dust impact assessment has been conducted. Results have concluded that there will not be any adverse residual air quality impacts during construction phase given frequent watering on all works area once per hour during working hours.

3.7.2 Operational Phase

3.7.2.1 Quantitative operational air quality assessment has been conducted taking into account the vehicular emission impacts associated with the Project and nearby existing road network, airport emission associated with the HKIA including its three-runway system, industrial emissions from OWTF, marine emissions associated with NLRTS and potential concurrent projects (including, but not limited to, induced traffic due to TM-CLK Link, etc.) in the vicinity. Cumulative impact from far-field source contributions, including territory wide vehicular emission, power plants, marine emission, as well as regional emission from PRD, have also been taken into account. It is concluded that the predicted cumulative air quality impacts on all ASRs would comply with the AQOs during the operational phase, and hence adverse impacts are not anticipated.

3.7.2.2 Quantitative odour assessment has been conducted taking into account contribution from existing (e.g. SHWSTW and NLRTS) and planned (e.g. OWTF and proposed SPS by the Project) odour sources. Adverse odour impact is not anticipated at all existing air sensitive uses and planned air sensitive uses within the proposed SHD Topside Development.

3.8 References

[3-1]            Sun Y., Wang L.L., Wang Y.S. (2010) “In situ measurements of SO₂, NO_x, NO_y, and O₃ in Beijing, China during August 2008” Science of the Total Environment 409 (2011), P933-940

[3-2]            Sun Y., Wang L.L., Wang Y.S. (2010) “In situ measurements of NO, NO₂, NO_y, and O₃ in Dinghushan (112°E, 23°N), China during autumn 2008”, Atmospheric Environment 44 (2010), P2079-2088

[3-3]            Environmental Protection Department (2015), Air Quality in Hong Kong 2015 (http://www.aqhi.gov.hk/api_history/english/report/files/AQR2015e_final.pdf)

[3-4]            Environmental Protection Department, A Study to Review Hong Kong’s Air Quality Objectives (http://www.epd.gov.hk/epd/english/environmentinhk/air/studyrpts/aqor_report.html)

[3-5]            Environmental Protection Department (2013), Assessment of Toxic Air Pollutant Measurements in Hong Kong (http://www.epd.gov.hk/epd/english/environmentinhk/air/studyrpts/assessment_of_tap_measurements.html)

[3-6]            European Monitoring and Evaluation Programme (2005), Sources of Poychlorinated Biphenyls Emissions (http://www.eea.europa.eu/publications/EMEPCORINAIR5/Sources_of_PCB_emissions.pdf/view)

[3-7]            Environmental Protection Department (2014), Hong Kong Air Pollutant Emission Inventory (http://www.epd.gov.hk/epd/english/environmentinhk/air/data/emission_inve.html)

[3-8]            Drainage Services Department (2015), 2014-15 Sustainability Report (http://www.dsd.gov.hk/Documents/SustainabilityReports/1415/en/odour_management.html)

[3-9]            Environmental Protection Department (2015), Implementation Schedule of Vehicle Emission Standards in Hong Kong (http://www.epd.gov.hk/epd/sites/default/files/epd/Appendix%20III_HK%20std%20%2802-11-2015%29_EMFAC-HK%20%28V3.1%29.pdf)

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