3. Air Quality impact

3.2 Environmental Legislations, Standards and Guidelines

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

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

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

· Air Pollution Control (Construction Dust) Regulation

· Air Pollution Control (Smoke) Regulation

· Air Pollution Control (Fuel Restriction) Regulation

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

· Recommended Pollution Control Clauses for Construction Contracts

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

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

Air Quality Objectives

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

Table 3.2.1 Hong Kong Air Quality Objectives (AQOs)

Pollutant	Averaging time	Concentration limit ^[1] (μg/m³)	Number of exceedances allowed
Sulphur dioxide (SO₂)	10-minute	500	3
Sulphur dioxide (SO₂)	24-hour	50	3
Respirable suspended particulates (PM₁₀) ^[2]	24-hour	100	9
Respirable suspended particulates (PM₁₀) ^[2]	Annual	50	Not applicable
Fine suspended particulates (PM_2.5) ^[3]	24-hour	50	35 (18)^[4]
Fine suspended particulates (PM_2.5) ^[3]	Annual	25	Not applicable
Nitrogen dioxide (NO₂)	1-hour	200	18
Nitrogen dioxide (NO₂)	Annual	40	Not applicable
Ozone	8-hour	160	9
Carbon monoxide (CO)	1-hour	30,000	0
Carbon monoxide (CO)	8-hour	10,000	0
Lead	Annual	0.5	Not applicable
Note: [1] All measurements of the concentration of gaseous air pollutants, i.e., Sulphur dioxide, nitrogen dioxide, ozone and carbon monoxide, are to be adjusted to a reference temperature of 293K and a reference pressure of 101.325KPa. [2] Respirable suspended particulates mean suspended particles in air with a nominal aerodynamic diameter of 10μm or less. [3] Fine suspended particulates mean suspended particles in air with a nominal aerodynamic diameter of 2.5μm or less. [4] The value 18 inside the bracket refers to annual number of exceedances allowed of daily PM2.5 for new government projects.

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

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

Air Pollution Control (Construction Dust) Regulation

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

Air Pollution Control (Smoke) Regulation

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

Air Pollution Control (Fuel Restriction) Regulation

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

· Gaseous fuel

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

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

Total Suspended Particulate Criteria

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

Odour Level

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

3.3 Baseline Condition

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

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

Pollutant	Averaging Time	Conc Limits (μg/m³)	Number of exceedances allowed	Concentration (μg/m³) ^[1]					Remark
Pollutant	Averaging Time	Conc Limits (μg/m³)	Number of exceedances allowed	2016	2017	2018	2019	2020	Remark
PM₁₀	24-hour	100	9	74	82	69	65	58	10^th highest conc.
PM₁₀	Annual	50	N.A.	29	32	31	31	24	N.A.
PM_2.5	24-hour	50	18	43	46	38	41	33	19^th highest conc.^[2]
PM_2.5	Annual	25	N.A.	20	22	19	20	15	N.A.
NO₂	1-hour	200	18	112	127	125	142	106	19^th highest conc.
NO₂	Annual	40	NA	33	39	36	36	30	NA
SO₂	10-minute	500	3	37	39	24	20	19	4^thhighest conc.
SO₂	24-hour	50	3	10	9	8	10	7	4^th highest conc.
O₃	8-hour	160	9	147	181	167	197	165	10^th highest conc.
Note: [1] Bolded concentrations indicate exceedance of the air quality objectives [2] No information of the 19^th highest daily FSP is available in Annual Air Quality Reports from 2016 – 2020, the 19^th highest daily FSP at Tai Po AQMS were obtained from the Environmental Protection Interactive Center (https://cd.epic.epd.gov.hk/EPICDI/air/?lang=en)..

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

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

3.3.4 As per Guidelines on Choices of Models and Model Parameters as published by EPD, the PM₁₀ and PM_2.5 output of PATH should be adjusted as below.

· Annual average concentrations, PM₁₀ (+10.3µg/m³), PM_2.5 (+3.5 µg/m³)

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

3.3.5 The NO₂, PM₁₀, PM_2.5, SO₂ , O₃ and CO concentrations predicted by PATH in Year 2025 within the concerned grids are summarized in Table 3.3.2 below.

Table 3.3.2 Summary of PATH Background Concentration in Year 2025

Pollutant	Averaging Time	Conc. Limits (μg/m³)	Number of Exceedances Allowed	Grid Concentration (μg/m³)						Remark
Pollutant	Averaging Time	Conc. Limits (μg/m³)	Number of Exceedances Allowed	34,51	34,52	34,53	35,51	35,52	35,53	Remark
PM₁₀	24-hour	100	9	65	67	68	68	65	65	10^th highest conc.
PM₁₀	Annual	50	N.A.	27	28	29	28	27	28	N.A.
PM_2.5	24-hour	50	18	36	36	39	39	36	36	19^th highest conc.
	24-hour	50	35	24	25	28	26	25	25	36^th highest conc.
	Annual	25	N.A.	15	16	17	16	16	16	N.A.
NO₂	1-hour	200	18	98	108	118	92	105	118	19^th highest conc.
NO₂	Annual	40	N.A.	13	14	18	13	14	17	N.A.
SO₂	10-min	500	3	60	79	82	57	76	79	4^th highest conc.
SO₂	24-hour	50	3	11	13	14	11	11	12	4^th highest conc.
O₃	8-hour	160	9	210	210	210	208	209	208	10^th highest conc.
CO	1-hour	30,000	0	923	930	944	915	922	936	0
CO	8-hour	10,000	0	840	845	852	835	840	848	0
Note: [1] Bolded concentrations indicate exceedance of the air quality objectives

3.4 Air Sensitive Receivers

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

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

Table 3.4.1 Representative ASRs in the vicinity of the Project

ASR ID	Description	Land Use [1]	Approximate Horizontal Distance from the Project (m)	Assessment Height Above Ground (mAG)	Construction Phase	Operation Phase
Existing ASRs
AH11	Ching Ho Estate – Ching Chiu House	R	157	1.5-100	✓	✓
AH12	Ching Ho Estate – Ching Ping House	R	218	1.5-100	✓	✓
AH13	Ching Ho Estate – Ching Yu House	R	384	1.5-100	✓	✓
AH21	Cheung Lung Wai Estate – Ching Cheung House	R	22	1.5-100	✓	✓
AH22	Cheung Lung Wai Estate – King Cheung House	R	61	1.5-100	✓	✓
AH31	Tai Ping Estate – Tai Ping Kindergarden	R	357	1.5	✓	✓
AH32	Tai Ping Estate – Ping Hay House	R	356	1.5-75	✓	✓
AH41	Choi Yuen Estate – Choi Lai House	R	470	1.5-50	✓	✓
AH42	Choi Yuen Estate – Choi Wu House	R	464	1.5-75	✓	✓
AH51	Royal Green – Tower 3	R	307	1.5-100	✓	✓
AH61	Glorious Peak	R	461	1.5-100	✓	✓
AH71	8 Royal Green	R	496	1.5-100	✓	✓
AH81	Venice Garden – Block 2	R	480	1.5-75	✓	✓
AH91	Eden Manor – Tower 2	R	423	1.5-75	✓	✓
AL11	King’s Gate – B1	R	366	1.5-10	✓	✓
AL21	The Green	R	277	1.5-10	×	✓
AL31	Residential R(C)2 (Land Lot 1909 in D.D. 100)	R	252	1.5-10	×	✓
AV11	Ng Uk Tsuen	R	373	1.5-10	✓	✓
AV21	Chong Tsin Leng	R	286	1.5-10	✓	✓
AV31	Ping Kong Village	R	5	1.5-10	✓	✓
AV32	Ming Tak Court	R	19	1.5-10	✓	✓
AV33	Ping Kong Village	R	156	1.5-10	✓	✓
AV41	On Po Tsuen	R	44	1.5-10	✓	✓
AV51	Tai Lung	R	288	1.5-10	×	✓
AV61	Lin Tong Mei Tsoi Yuen	R	152	1.5-10	×	✓
AV71	Lin Tong Mei	R	38	1.5-10	×	✓
AV72	Lin Tong Mei	R	320	1.5-10	×	✓
AV81	Chan Uk Po	R	467	1.5-10	×	✓
AV91	Tong Kung Leng	R	284	1.5-10	×	✓
AW11	Catholic Diocese of Hong Kong Mother of Christ Church	W	324	1.5-15	✓	✓
AW21	Ping Kong Tin Hau Temple	W	170	1.5-5	✓	✓
AW31	Ebenezer Christian Church	W	154	1.5-5	×	✓
AS11	TWGHs Ma Kam Chan Memorial Primary School	E	51	1.5-25	✓	✓
AS21	HHCKLA Buddhist Wisdom Primary School	E	34	1.5-25	✓	✓
AS31	Tsang Mui Millennium School	E	155	1.5-25	✓	✓
AS41	Elegantia College	E	48	1.5-25	✓	✓
AS42	Elegantia College	E	66	1.5-25	✓	✓
AM11	North District Hospital	G/IC	105	33.8^[2]	✓	✓
AM12	North District Hospital	G/IC	98	33.8^[2]	✓	✓
AM13	North District Hospital	G/IC	112	33.8^[2]	✓	✓
AM14	North District Hospital	G/IC	128	33.8^[2]	✓	✓
AM15	North District Hospital	G/IC	176	33.8^[2]	✓	✓
AM16	North District Hospital	G/IC	186	33.8^[2]	✓	✓
AM17	North District Hospital	G/IC	168	33.8^[2]	✓	✓
AM21	Little Sisters of the Poor Saint Joseph’s Home for the Aged	G/IC	211	1.5-20	✓	✓
AM31	Buddhist Li Chong Yuet Ming Nursing Home for The Elderly	G/IC	320	1.5-25	✓	✓
AG11	The Hong Kong Golf Club	Rec	69	1.5-10	✓	✓
AG12	The Hong Kong Golf Club	Rec	25	1.5	✓	✓
AF11	Tai Lung Experiment Farm	G/IC	53	1.5-10	×	✓
AF12	Tai Lung Experiment Farm	G/IC	173	1.5-10	×	✓
AF21	Tai Lung Veterinary Laboratory	G/IC	5	1.5-10	×	✓
AF31	Hong Kong Canine Working and Agility Club Limited	C	25	1.5-5	×	✓
Planned ASRs
PH11	Proposed Public Housing at Ching Hiu Road	R	258	1.5-100	×	✓
PH21	Proposed Public Housing at Tai Tau Leng	R	417	1.5-100	×	✓
PL11	Proposed Residential (Land Lot 4076 in D.D. 91)	R	229	1.5-10	×	✓
PM11	North District Hospital Expansion	G/IC	137	33.8^[3]	×	✓
PM12	North District Hospital Expansion	G/IC	112	33.8^[3]	×	✓
PM13	North District Hospital Expansion	G/IC	257	33.8^[3]	×	✓
Proposed Development ASRs
B011	Block 1	R	-	1.5 – 106	×	✓
B012	Block 1	R	-	1.5 – 106	×	✓
B013	Block 1	R	-	1.5 – 106	×	✓
B014	Block 1	R	-	1.5 – 106	×	✓
B021	Block 2	R	-	1.5 – 103.2	×	✓
B022	Block 2	R	-	1.5 – 103.2	×	✓
B023	Block 2	R	-	1.5 – 103.2	×	✓
B024	Block 2	R	-	1.5 – 103.2	×	✓
B031	Block 3	R	-	1.5 – 119.6	×	✓
B032	Block 3	R	-	1.5 – 119.6	×	✓
B033	Block 3	R	-	1.5 – 119.6	×	✓
B034	Block 3	R	-	1.5 – 119.6	×	✓
B041	Block 4	R	-	1.5 – 119.6	×	✓
B042	Block 4	R	-	1.5 – 119.6	×	✓
B043	Block 4	R	-	1.5 – 119.6	×	✓
B051	Block 5	R	-	1.5 – 103.2	×	✓
B052	Block 5	R	-	1.5 – 103.2	×	✓
B053	Block 5	R	-	1.5 – 103.2	×	✓
B054	Block 5	R	-	1.5 – 103.2	×	✓
B061	Block 6	R	-	1.5 – 137.6	×	✓
B062	Block 6	R	-	1.5 – 137.6	×	✓
B063	Block 6	R	-	1.5 – 137.6	×	✓
B064	Block 6	R	-	1.5 – 137.6	×	✓
B071	Block 7	R	-	1.5 – 100.4	×	✓
B072	Block 7	R	-	1.5 – 100.4	×	✓
B073	Block 7	R	-	1.5 – 100.4	×	✓
B074	Block 7	R	-	1.5 – 100.4	×	✓
B081	Block 8	R	-	1.5 – 132.9	×	✓
B082	Block 8	R	-	1.5 – 132.9	×	✓
B083	Block 8	R	-	1.5 – 132.9	×	✓
B084	Block 8	R	-	1.5 – 132.9	×	✓
B091	Block 9	R	-	1.5 – 103.2	×	✓
B092	Block 9	R	-	1.5 – 103.2	×	✓
B093	Block 9	R	-	1.5 – 103.2	×	✓
B094	Block 9	R	-	1.5 – 103.2	×	✓
B101	Block 10	R	-	1.5 – 128.9	×	✓
B102	Block 10	R	-	1.5 – 128.9	×	✓
B103	Block 10	R	-	1.5 – 128.9	×	✓
B104	Block 10	R	-	1.5 – 128.9	×	✓
B111	Block 11	R	-	1.5 – 128.9	×	✓
B112	Block 11	R	-	1.5 – 128.9	×	✓
B113	Block 11	R	-	1.5 – 128.9	×	✓
B114	Block 11	R	-	1.5 – 128.9	×	✓
B121	Block 12	R	-	1.5 – 128.9	×	✓
B122	Block 12	R	-	1.5 – 128.9	×	✓
B123	Block 12	R	-	1.5 – 128.9	×	✓
CF01	Community Facilities	Rec	-	15-39 ^[4]	×	✓
CF02	Community Facilities	Rec	-	15-39 ^[4]	×	✓
CF03	Community Facilities	Rec	-	15-39 ^[4]	×	✓
CF04	Community Facilities	Rec	-	15-39 ^[4]	×	✓
CF05	Community Facilities	Rec	-	15-39 ^[4]	×	✓
CP01	Podium	Rec	-	15 ^[4]	×	✓
CP02	Podium	Rec	-	15 ^[4]	×	✓
CP03	Podium	Rec	-	15 ^[4]	×	✓
CP04	Podium	Rec	-	21 ^[4]	×	✓
CP05	Podium	Rec	-	21 ^[4]	×	✓
CP06	Podium	Rec	-	21 ^[4]	×	✓
CS01	Proposed School	E	-	1.5 - 25	×	✓
CS02	Proposed School	E	-	1.5 - 25	×	✓
CS03	Proposed School	E	-	1.5 - 25	×	✓
CS04	Proposed School	E	-	1.5 - 25	×	✓
CS05	Proposed School	E	-	1.5 - 25	×	✓
CS06	Proposed School	E	-	1.5 - 25	×	✓
PP01	Proposed Visiting Centre	Rec	-	1.5	×	✓
PP02	Proposed Visiting Centre	Rec	-	1.5	×	✓
PP03	Proposed Visiting Centre	Rec	-	1.5	×	✓
PP04	Proposed Visiting Centre	Rec	-	1.5	×	✓
Note: [1] R - Residential; E - Education; G/IC - Government, Institution and Community; Rec – Recreational; C – Commercial; H – Hospital or Home for Aged; W – Place for Public Worship [2] Fresh air intake level at North District Hospital. [3] Assume the same as existing North District Hospital as no information was provided in this stage. [4] Lowest level of the usage above ground level

3.5 Identification of Environmental Impacts

Construction Phase

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

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

· Wind erosion of exposed open area.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

3.5.8 The temporary dust nuisance, measurable as TSP, PM₁₀ and PM_2.5, would be generated as a result of construction activities during site clearance, site formation and earth works. Particulate matters (TSP, PM₁₀ and PM_2.5) would be the pollutants to be concerned during the construction phase. The impacts are quantitatively assessed.

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

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

Table 3.5.1 Summary of Potential Concurrent Projects for Construction Dust Impact

Potential Concurrent Projects	Tentative Construction Commencement Year	Target Operation/ Target Completion of Development	Approx. Horizontal Distance from Project Boundary (m)
Potential Housing Developments in North District - Ching Hiu Road	2022	2030	380
Potential Housing Developments in North District - Tai Tau Leng	2025	2032	480
North District Hospital Expansion	2021	2030	85
Drainage Improvements at North District	2021	2027	290 (SE of Project) / 310 (S of Project)
Fanling Highway Widening	2024	2031	450
Po Shek Wu Flyover	2024	2029	470
Road Improvement Works at Fan Kam Road	Not Available	Not Available	100
Fanling Area 36 Phase 4 (Ching Ho Extension)	2020	2024	480
Private Housing Development at Lot 4076 in D.D. 91	Not Available	2028	295
Reclaimed Water Supply to Sheung Shui and Fanling – Investigation, Design and Construction	2020	2025	845
Sheung Shui Lot 2RP in DD 92, Sheung Shui	Not Available	2023	519
So Kwun Po Interchange	2025	2030	587
Retrofitting of Noise Barriers on Po Shek Wu Road	2024	2028	1700

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

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

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

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

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

Operation Phase

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

· Vehicular emissions from road networks within the assessment area;

· Chimney emissions from North District Hospital;

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

· Background pollutant concentrations.

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

Identification of Representative Air Pollutants of Vehicle Emissions

3.5.18 The air quality pollutant source during the operational phase of the project would be the emission from the travelling vehicles. The tailpipe emission comprises a number of pollutants, including Nitrogen Oxides (NO_X), PM₁₀, PM_2.5, SO₂, CO, O₃, Toxic Air Pollutants (TAPs), Lead (Pb) etc. Determination of representative air pollutants for this Project is discussed as below.

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

3.5.20 PM₁₀ and PM_2.5 refer to suspended particulates with nominal diameter of 10µm or less and 2.5µm or less respectively. Both particulate matters are considered as key pollutants of increasing of traffic flows of the Project as the vehicular emissions contribute 9% of PM₁₀ and 11% of PM_2.5 of the total emissions in 2019.

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

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

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

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

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

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

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

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

Identification of Representative Air Pollutants of Chimneys Emissions

3.5.29 The fuel used by nearby chimneys emissions are towngas which is extremely low in sulphur content . Therefore, the concerned pollutants during operation phase are NO₂ and PM₁₀, PM_2.5.

Identification of Odour Impact

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

3.6 Construction Phase Assessment Methodology

Dust Emission associated with the Project and other Sources

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

Table 3.6.1 Emission Factors for Construction Dust Impact Assessment

Source

Activities

Emission Factors

All construction sites

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

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

PM₁₀ = 9.82 x 10^-5 g/m²/s

PM_2.5 = 1.49 x 10^-5 g/m²/s

Wind erosion

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

PM₁₀ = 1.27 x 10^-6 g/m²/s

PM_2.5 = 1.94 x 10^-7 g/m²/s

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

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

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

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

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

Methodology and Assumptions of Dispersion Model – Construction Activities

Dispersion Model

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

Meteorological Data

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

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

Model Approach

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

Table 3.6.2 Particle Size Distribution

Particle Size, µg	Average Particle Size, µg	TSP Distribution	PM₁₀ Distribution	PM_2.5 Distribution
15 – 30	22.5	35%	--	--
10 – 15	12.5	18%	--	--
5 – 10	7.5	20%	43%	--
2.5 – 5	3.75	20%	42%	--
0 – 2.5	1.25	7%	15%	100%

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

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

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

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

3.7 Construction Assessment Results

Unmitigated Scenario

3.7.1 The predicted TSP, PM₁₀ and PM_2.5 impact at the worst affected level arising from unmitigated construction activities are summarised in Table 3.7.1, Table 3.7.2 and Table 3.7.3. Details of predicted concentrations are shown in Appendix 3.3.

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

ASRs	Worst Affected Height, mAG	TSP Concentrations (µg/m³)
ASRs	Worst Affected Height, mAG	Highest Hourly Averaged
AH11	10.0	1537.9
AH12	10.0	1575.7
AH13	15.0	1145.3
AH21	1.5	4158.6
AH22	5.0	2947.6
AH31	1.5	946.7
AH32	15.0	1148.3
AH41	15.0	1116.0
AH42	20.0	1365.1
AH51	15.0	1240.1
AH61	15.0	981.1
AH71	15.0	912.1
AH81	20.0	820.5
AH91	20.0	783.9
AL11	1.5	651.7
AV11	10.0	1096.1
AV21	10.0	1227.3
AV31	10.0	2323.6
AV32	1.5	2815.7
AV33	10.0	1594.1
AV41	10.0	1544.3
AW11	15.0	1330.7
AW21	5.0	1296.7
AS11	5.0	3137.4
AS21	5.0	3198.7
AS31	10.0	1876.5
AS41	5.0	2490.8
AS42	5.0	2176.2
AM11	33.8	533.0
AM12	33.8	551.2
AM13	33.8	543.8
AM14	33.8	523.1
AM15	33.8	459.2
AM16	33.8	399.4
AM17	33.8	428.7
AM21	10.0	1631.4
AM31	15.0	1212.6
AG11	5.0	2326.3
AG12	1.5	3283.1
Standard		500
Note: Concentrations exceed the standard are shown in in red and bold

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

ASRs	Worst Affected Height, mAG		PM₁₀ Concentrations (µg/m³)
ASRs	10^th Highest Daily Averaged	Annual Averaged	10^th Highest Daily Averaged	Annual Averaged
AH11	1.5	1.5	74.5	32.2
AH12	1.5	1.5	75.3	32.1
AH13	1.5	1.5	71.9	29.9
AH21	1.5	1.5	250.1	84.1
AH22	1.5	1.5	160.6	58.5
AH31	1.5	1.5	67.5	33.7
AH32	15.0	1.5	70.1	33.8
AH41	1.5	1.5	73.8	33.4
AH42	15.0	1.5	73.5	32.9
AH51	1.5	1.5	78.1	34.4
AH61	1.5	1.5	71.7	30.5
AH71	1.5	1.5	71.2	30.0
AH81	1.5	1.5	65.6	31.8
AH91	1.5	1.5	76.1	33.5
AL11	1.5	1.5	72.6	33.0
AV11	1.5	1.5	68.9	31.7
AV21	1.5	1.5	71.2	29.1
AV31	1.5	1.5	103.9	37.4
AV32	1.5	1.5	102.1	38.0
AV33	1.5	1.5	83.7	31.3
AV41	10.0	5.0	84.6	32.3
AW11	1.5	1.5	87.6	42.9
AW21	1.5	1.5	78.5	30.3
AS11	1.5	1.5	166.5	59.6
AS21	1.5	1.5	156.6	53.2
AS31	1.5	1.5	77.7	34.4
AS41	1.5	1.5	99.5	35.7
AS42	1.5	1.5	96.0	36.4
AM11	33.8	33.8	69.6	34.1
AM12	33.8	33.8	71.5	34.4
AM13	33.8	33.8	70.9	34.1
AM14	33.8	33.8	68.8	33.7
AM15	33.8	33.8	65.6	32.5
AM16	33.8	33.8	66.4	33.5
AM17	33.8	33.8	66.8	33.9
AM21	1.5	1.5	85.3	37.8
AM31	1.5	1.5	78.0	39.5
AG11	1.5	1.5	165.3	66.7
AG12	1.5	1.5	295.8	118.6
Standard			100	50
Note: Concentrations exceed the standard are shown in in red and bold

Table 3.7.3 Predicted PM_2.5 Concentration at Worst Affected Level of ASRs – Unmitigated Scenario

ASRs	Worst Affected Height, mAG				PM_2.5 Concentrations (µg/m³)
ASRs	36th Highest Daily Averaged Conc.	19th Highest Daily Averaged Conc.	Annual Averaged Conc.		36th Highest Daily Averaged Conc.		19th Highest Daily Averaged Conc.	Annual Averaged Conc.
AH11	5.0	1.5	1.5		25.8		38.4	16.5
AH12	1.5	1.5	1.5		25.9		38.4	16.5
AH13	1.5	10.0	1.5		25.8		36.8	16.1
AH21	1.5	1.5	1.5		43.3		49.7	25.6
AH22	1.5	1.5	1.5		31.4		42.1	21.3
AH31	1.5	1.5	1.5		26.1		36.0	17.2
AH32	1.5	1.5	1.5		25.9		35.8	17.2
AH41	1.5	1.5	1.5		26.2		35.9	17.3
AH42	1.5	1.5	1.5		26.0		35.9	17.1
AH51	1.5	1.5	1.5		26.5		38.2	17.2
AH61	1.5	1.5	1.5		25.9		36.4	16.5
AH71	1.5	1.5	1.5		25.3		36.0	16.2
AH81	1.5	1.5	1.5		25.7		35.7	16.8
AH91	1.5	1.5	1.5		27.0		37.8	17.1
AL11	1.5	1.5	1.5		26.6		37.5	16.9
AV11	1.5	1.5	1.5		25.3		36.2	16.5
AV21	1.5	1.5	1.5		25.2		36.0	15.9
AV31	1.5	1.5	1.5		29.4		41.4	17.4
AV32	1.5	1.5	1.5		28.3		39.2	17.4
AV33	1.5	1.5	1.5		26.7		36.2	16.3
AV41	5.0	10.0	1.5		27.5		39.3	16.5
AW11	1.5	1.5	1.5		27.1		36.2	18.6
AW21	1.5	1.5	1.5		26.7		36.2	16.1
AS11	1.5	1.5	1.5		32.5		42.6	21.4
AS21	1.5	1.5	1.5		30.8		42.7	20.3
AS31	1.5	1.5	1.5		26.0		38.5	17.0
AS41	1.5	1.5	1.5		26.8		39.4	17.1
AS42	1.5	1.5	1.5		26.9		38.9	17.3
AM11	33.8	33.8	33.8		25.3		36.1	16.8
AM12	33.8	33.8	33.8		25.3		36.1	16.8
AM13	33.8	33.8	33.8		25.3		36.1	16.8
AM14	33.8	33.8	33.8		25.3		36.1	16.7
AM15	33.8	33.8	33.8		25.3		36.1	16.5
AM16	33.8	33.8	33.8		25.9		35.7	16.8
AM17	33.8	33.8	33.8		26.0		35.7	16.9
AM21	1.5	1.5	1.5		27.1		38.0	17.6
AM31	1.5	1.5	1.5		26.7		36.0	18.1
AG11	1.5	1.5	1.5		37.1		46.6	22.8
AG12	1.5	1.5	1.5		55.9		65.5	32.2
Standard				50		50^[1]		25
Note: Concentrations exceed the standard are shown in in red and bold [1] For new government project

3.7.2 Exceedances of TSP standard were predicted amongst most of the representative ASRs. Annual averaged and daily averaged PM₁₀ and PM_2.5 objectives are exceeded at numbers of ASRs.

Recommended Mitigation Measures

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

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

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

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

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

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

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

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

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

· Deploy NRMMs as far as practicable;

· Exempted NRMMs are not allowed;

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

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

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

Mitigated Scenario

3.7.4 The predicted TSP, PM₁₀ and PM_2.5 impact at the worst affected level arising from construction activities with implementation of mitigated measures are summarised in Table 3.7.4, Table 3.7.5 and Table 3.7.6. Details of predicted concentrations are shown in Appendix 3.3. Contours of particulate matters at ground level (1.5mAG) as the worst impact level are presented in Figures 3.5a-f.

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

ASRs	Worst Affected Height, mAG	TSP Concentrations (µg/m³)
ASRs	Worst Affected Height, mAG	Highest Hourly Average
AH11	1.5	194.5
AH12	1.5	194.6
AH13	1.5	192.5
AH21	1.5	359.7
AH22	1.5	264.2
AH31	1.5	194.9
AH32	15.0	195.5
AH41	15.0	321.7
AH42	15.0	341.1
AH51	1.5	244.9
AH61	1.5	189.3
AH71	1.5	189.0
AH81	15.0	194.0
AH91	10.0	203.5
AL11	1.5	197.7
AV11	10.0	191.9
AV21	1.5	192.4
AV31	10.0	239.1
AV32	1.5	305.9
AV33	1.5	199.9
AV41	10.0	194.7
AW11	1.5	444.1
AW21	1.5	196.0
AS11	1.5	283.6
AS21	1.5	280.5
AS31	1.5	194.5
AS41	1.5	252.6
AS42	5.0	212.9
AM11	33.8	203.2
AM12	33.8	201.4
AM13	33.8	201.4
AM14	33.8	202.5
AM15	33.8	204.2
AM16	33.8	207.0
AM17	33.8	208.1
AM21	10.0	197.1
AM31	1.5	332.4
AG11	5.0	253.3
AG12	1.5	322.8
Standard		500

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

ASRs	Worst Affected Height, mAG		PM₁₀ Concentrations (µg/m³)
ASRs	10^th Highest Daily Average	Annual Average	10^th Highest Daily Average	Annual Average
AH11	5.0	1.5	66.5	28.3
AH12	1.5	1.5	67.1	28.4
AH13	1.5	1.5	65.1	27.9
AH21	1.5	1.5	70.6	35.4
AH22	1.5	1.5	68.3	32.3
AH31	1.5	1.5	65.9	29.7
AH32	1.5	1.5	65.8	29.7
AH41	1.5	1.5	65.5	30.9
AH42	1.5	1.5	65.6	30.6
AH51	1.5	1.5	71.5	31.0
AH61	1.5	1.5	64.8	28.5
AH71	1.5	1.5	64.7	28.1
AH81	1.5	1.5	65.6	29.2
AH91	1.5	1.5	76.1	32.2
AL11	1.5	1.5	72.6	31.2
AV11	1.5	1.5	65.3	28.5
AV21	1.5	1.5	65.2	27.7
AV31	1.5	1.5	73.3	29.1
AV32	1.5	1.5	68.8	28.9
AV33	1.5	1.5	69.1	28.1
AV41	5.0	5.0	72.6	28.2
AW11	1.5	1.5	72.4	38.4
AW21	1.5	1.5	68.6	27.9
AS11	1.5	1.5	68.0	32.3
AS21	1.5	1.5	67.8	31.3
AS31	5.0	1.5	67.6	28.8
AS41	1.5	1.5	67.4	28.8
AS42	1.5	1.5	67.3	29.0
AM11	33.8	33.8	66.4	28.1
AM12	33.8	33.8	66.2	28.1
AM13	33.8	33.8	65.9	28.1
AM14	33.8	33.8	65.8	28.0
AM15	33.8	33.8	65.6	27.9
AM16	33.8	33.8	66.4	28.6
AM17	33.8	33.8	66.6	28.6
AM21	1.5	1.5	66.9	30.3
AM31	1.5	1.5	67.3	34.8
AG11	1.5	1.5	74.5	33.6
AG12	1.5	1.5	84.2	39.6
Standard			100	50

Table 3.7.6 Predicted PM_2.5 Concentration at Worst Affected Level of ASRs – Mitigated Scenario

ASRs	Worst Affected Height, mAG			PM_2.5 Concentrations (µg/m³)
ASRs	36th Highest Daily Average Conc.	19th Highest Daily Average Conc.	Annual Average Conc.	36th Highest Daily Average Conc.	19th Highest Daily Average Conc.	Annual Average Conc.
AH11	1.5	1.5	5.0	25.2	36.1	15.9
AH12	1.5	1.5	1.5	25.3	36.2	15.9
AH13	1.5	1.5	1.5	25.2	36.1	15.8
AH21	1.5	1.5	1.5	25.5	36.6	17.2
AH22	1.5	1.5	1.5	25.5	36.5	16.6
AH31	1.5	1.5	1.5	25.9	36.0	16.5
AH32	1.5	1.5	1.5	25.8	35.8	16.4
AH41	1.5	1.5	1.5	26.0	35.9	16.9
AH42	1.5	1.5	1.5	26.0	35.9	16.8
AH51	1.5	1.5	1.5	25.8	36.6	16.6
AH61	1.5	1.5	1.5	25.9	36.4	16.2
AH71	1.5	1.5	1.5	25.3	36.0	15.8
AH81	1.5	1.5	1.5	25.6	35.7	16.4
AH91	1.5	1.5	1.5	27.0	37.3	16.8
AL11	1.5	1.5	1.5	26.6	36.9	16.6
AV11	1.5	1.5	1.5	25.3	36.2	16.0
AV21	1.5	1.5	1.5	25.2	36.0	15.7
AV31	1.5	1.5	1.5	25.3	36.6	15.9
AV32	1.5	1.5	1.5	25.3	36.2	15.9
AV33	1.5	1.5	1.5	25.3	36.3	15.8
AV41	5.0	1.5	10.0	25.3	36.5	15.8
AW11	1.5	1.5	1.5	26.7	36.2	17.8
AW21	1.5	1.5	1.5	25.2	36.2	15.7
AS11	1.5	1.5	1.5	25.4	36.4	16.6
AS21	1.5	1.5	1.5	25.4	36.4	16.4
AS31	1.5	1.5	1.5	25.3	36.3	16.0
AS41	1.5	1.5	1.5	25.3	36.3	16.0
AS42	1.5	1.5	1.5	25.4	36.4	16.1
AM11	33.8	33.8	33.8	25.3	36.1	15.8
AM12	33.8	33.8	33.8	25.3	36.1	15.8
AM13	33.8	33.8	33.8	25.3	36.1	15.8
AM14	33.8	33.8	33.8	25.3	36.1	15.8
AM15	33.8	33.8	33.8	25.3	36.1	15.7
AM16	33.8	33.8	33.8	25.4	35.7	16.0
AM17	33.8	33.8	33.8	25.4	35.7	16.0
AM21	1.5	1.5	1.5	25.9	36.6	16.3
AM31	1.5	1.5	1.5	26.0	36.0	17.3
AG11	1.5	1.5	1.5	27.2	38.1	16.9
AG12	1.5	1.5	1.5	28.1	40.1	17.9
Standard				50	50^[1]	25
Note: [1] For new government project

3.7.5 No exceedances of AQOs at representative ASRs are predicted under the mitigated scenario.

Residual Impact

3.7.6 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 hourly TSP, daily and annual PM₁₀ / PM_2.5 concentrations on all sensitive uses in the vicinity of the construction sites would comply with the respective criteria. To further minimise the impact of NRMM the following measures should avoid use of diesel generators and diesel-powered equipment by connecting construction plant and equipment to mains electricity supply.

3.7.7 Hence, no adverse residual air quality impact during construction phase is anticipated.

3.8 Operation Phase Assessment Methodology

Methodology and Assumptions for Estimation of Vehicular Emission Inventory

Model Version

3.8.1 The EMFAC-HK model (version 4.3) issued by EPD was employed to estimate the vehicular emission inventory for the assessment.

Traffic Forecast

3.8.2 3 years of traffic forecast data for roads within the assessment area in Years 2029 (commencement year of the Project), 2036 and 2044 (i.e. 15 years after the commencement year) were provided by the traffic consultant of the project. Traffic flows induced from the Projects and planned concurrent projects are considered in the traffic forecast data. The details of the traffic flows data are presented in Appendix 3.4.

Model Mode

3.8.3 EMFAC mode was selected in the model for hourly vehicular emission outputs.

Speed

3.8.4 24-hourly road traffic speeds for all road links were provided by the traffic consultant. All 18 types of vehicle were assumed to travel at the same hourly speed for each individual road link based on the site survey. The hourly speeds for each of road link are shown in Appendix 3.4. In accordance with the Road Traffic Ordinance (Cap. 374), for any road with design speed limit of 70kph or above, the maximum speed limit for medium goods vehicles, heavy goods vehicles, buses are limited to 70kph. The maximum travel speed for public light buses is limited to 80kph. These types of vehicles are kept with the above speed limits if the speeds of the roads are higher than the speed limits.

Road Grouping

3.8.5 The modelled roads were categorised into 2 groups with and without trips for the road sources based on site survey. The groups for each of road link are shown in Appendix 3.4.

Vehicular Population

3.8.6 The default vehicles population forecast as in EMFAC-HK was adopted as part of the input parameters.

Exhaust and Evaporation Technology Fractions

3.8.7 The default technology fraction as in EMFAC-HK was adopted.

Vehicle Accrual

3.8.8 The default vehicle accrual as in the model was adopted in the assessment.

Vehicle Kilometre Travelled (VKT)

3.8.9 The default VKT as in the model was adopted in the assessment and the values are presented in Appendix 3.5.

Trips

3.8.10 Based on site survey, diurnal variation of daily trips for estimation of cold start emissions were adopted for the group of roads as Appendix 3.4. Start emissions were assumed for the roads with on-street parking spaces according to on-site survey. Parking site for franchised bus, public light bus and non-franchised bus (or coach) other than PTIs was not identified within assessment area under site survey. Start emissions from franchised bus and public light bus were localized in PTI using precise approach, which was described in Sections 3.8.29 and 3.8.30.. Broad-brush approach was adopted for estimating the start emissions from other vehicle classes except franchised bus and public light bus. Under the broad-brush approach, start emission is estimated through estimation of the total number of trips in the study area on the basis of the project-specific vehicle-kilometre travelled (VKT) and the assumption that the number of trips per VKT in the study area is similar to the territory-wide number of trips per VKT, which was estimated using the following formula:

Trip for local and rural roads within the study area

VKT for local and rural roads within Hong Kong

= 12.58% x Territory-wide VKT within Hong Kong, where 12.58% is the proportion of local and rural roads in Hong Kong obtained from the Annual Traffic Census prepared by Transport Department, and trips for local and rural roads and territory-wide VKT within Hong Kong are extracted from EMFAC-HK model.

3.8.11 For each vehicle class (other than public light bus and bus) which has been considered in the modelling assessment, the maximum emission factor of start emission among various soaking time were adopted for the calculation of start emissions. The default Trips as in the model was adopted and the values are presented in Appendix 3.5.

Temperature and Relative Humidity

3.8.12 The 2019 hourly temperature and relative humidity profiles of the nearest Hong Kong Observatory (HKO) station, Sheung Shui Automatic Weather Station are adopted for the model. Data are presented in Appendix 3.6. For conservative approach, the lowest hourly temperature and relative humidity (7ºC and 25%) are employed.

Determination of Worst Model Year

3.8.13 Vehicular emissions on residual NO_X, NO₂, PM₁₀ and PM_2.5 on traffic forecast in the population intake year (2029), mid-year between population intake year (2036) and 15 years after the population intake (2044) is presented in Appendix 3.7.

3.8.14 A sensitivity test was conducted to compare the above years. Summary of the total composite vehicular emission factors on NO_X, NO₂, PM₁₀ and PM_2.5 for those year are presented in Appendix 3.8. The predicted results for Year 2029 has the highest composite vehicular emission factors which was adopted as the worst-case for the assessment.

Methodology and Assumptions of Dispersion Model for Open Roads

Dispersion Model

3.8.15 CALINE4 was employed to assess the potential vehicular emission impact of open road traffic.

3.8.16 The composite emission factor of each individual road was calculated based on its respective hourly trafﬁc flow and hourly speed-dependent emission factor as derived from the predicted emission factors of EMFAC-HK model. Detailed composite emission factors are summarised in Appendix 3.8.

3.8.17 The Ozone Limiting Method (OLM) was used for the conversion of residual NO_X to NO₂ and presented below.

[NO₂]_{total vehicular} = [NO₂]_vehicular + MIN{ [residual NO_x]_vehicular or (46/48)×[O₃]_PATH}

3.8.18 The noise remedies recommended in Chapter 4 of this study have insignificant impact on air quality. Therefore, comparison between with and without noise remedies scenarios is not required.

Meteorological Data

3.8.19 The Weather Research and Forecasting (WRF) metrological data extracted from the PATH model for grids (34,51), (35,52) and (35,53) was used.

3.8.20 Typical surface roughness used for new development area, 100cm as per EPD’s “Guidelines on Choices of Models and Model Parameters” was adopted in the model.

3.8.21 Stability classes for the model were derived from the PCRAMMET model. For wind speeds that are below 1m/s in PATH model are capped at 1m/s for the treatment of calm hours.

3.8.22 The standard deviation of wind angles for the model input were derived according to the “Meteorological Monitoring Guidance for Regulatory Modelling Applications, February 2000 (EPA-454/R-99-005)”. Table 3.8.1 below shows the derived standard deviation of wind angles.

Table 3.8.1 Standard Deviation of Wind Angles for the Assessment

Stability Class	Standard Deviation of Wind Angles	Standard Deviation of Wind Angles for the Assessment [1]
A	22.5	32.9
B	22.5	32.9
C	17.5	25.6
D	12.5	18.3
E	7.5	11
F	3.8	5.6
Note: [1] Adjustment factor: (z₀/15)^0.2 where z₀ is the project surface roughness length (100cm was assumed)

Methodology and Assumptions of Dispersion Model for Chimney Emissions

3.8.23 As mentioned in Section 3.5.16, chimney emissions were identified at North District Hospital.

3.8.24 Information of existing chimneys for North District Hospital was provided by Hospital Authority (HA). There is no information provided for the proposed expansion at this stage of the assessment. Emissions as existing chimneys were assumed as proposed chimney emissions for the planned expansion.

3.8.25 Detailed information of the chimneys for the assessment are summarised in Appendix 3.10.

Dispersion Model

3.8.26 The chimney emissions were modelled by using a steady-state plume model, AERMOD. The model is accepted by EPD with reference to “Guidelines on Choices of Models and Model Parameters” issued by EPD.

3.8.27 The OLM was adopted for the conversion of NO_X to NO₂ of chimney emissions impact. Referring to the Heathrow Airport EIA report (2007), the ratio of NO₂/NO_X as 10% for the chimney tip emission was adopted in the assessment. The conversion equation is presented below.

[NO₂]_chimney = 0.1×[NO_x]_chimney + MIN{0.9×[ NO_x]_chimney or (46/48)×[O₃]_PATH}

Meteorological Data

3.8.28 Meteorological data as Section 3.6.8 and Section 3.6.9 was employed.

Methodology and Assumptions of Dispersion Model for PTIs and Carparks

3.8.29 The start emissions and running exhaust emissions associated with the vehicles at the proposed and existing PTIs within the assessment area were predicted by EMFAC-HK model. Cold idling emission factors were calculated as per EPD published “Calculation of Start Emissions in Air Quality Impact Assessment”. Warm idling emission factors were from “Road Tunnels: Vehicle Emissions and Air Demand for Ventilation” which was published by World Road Association 2019. Traffic flows of the PTIs was provided by the Project traffic engineer.

3.8.30 The existing PTIs at Ching Ho Estate and Tai Ping Estate are surface opened PTI and the proposed PTI of the Project is semi-enclosed and ventilated at the entrance/exit of the PTI. Calculations of emissions associated with PTIs were made reference to the “Calculation of Start Emissions in Air Quality Impact Assessment”. Start emissions for diesel vehicles fitted with selective catalytic reduction (SCR) devices and LPG vehicles were adjusted based on the idling emission and would be released over a total spread distance of 700 m and 150 m respectively from where the start takes place, while running exhaust and idling emissions would be released on the spot. The locations of emission sources and the detailed calculation of the emissions are presented in Appendix 3.11.

3.8.31 Two 3-storey carparks with opening on sides would be proposed for the Project which were modelled with similar methodology and assumption as PTIs as above. Detailed calculation of the emissions is provided in Appendix 3.12. There is no large-scale private carpark within the assessment area. However, trips were included at roads outside of carparks as broad-brush approach. A sensitivity test was conducted between the broad-brush approach and precise calculation of an existing carpark which broad-brush approach provide generally more conservative results at nearby ASRs and the emission from carpark is insignificant.

3.8.32 AERMOD is used as the dispersion for the emission impacts from PTIs and Carparks.

3.9 Operation Phase Assessment Results

3.9.1 The cumulative impacts of NO₂, PM₁₀ and PM_2.5 arising from vehicular emissions from open roads, PTIs, chimneys emissions and the PATH background concentrations were evaluated. The predicted cumulative concentrations (NO₂, PM₁₀, and PM_2.5) at the worst affected level amongst all of the assessment points are summarized in Table 3.9.1, Table 3.9.2 and Table 3.9.3 below, respectively. Details of the cumulative results are shown in Appendix 3.13. Contours of NO₂, PM₁₀ and PM_2.5 at ground level (1.5mAG) are presented in Figures 3.6a-g.

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

ASR ID	Worst Affected Height (mAG)		NO₂ Concentrations (µg/m³)
ASR ID	19^th Highest Hourly Average	Annual Average	19^th Highest Hourly Average	Annual Average
AH11	1.5	1.5	114.3	17.7
AH12	5.0	1.5	112.5	17.4
AH13	5.0	1.5	114.2	17.6
AH21	1.5	1.5	125.9	24.9
AH22	1.5	1.5	117.7	22.8
AH31	1.5	1.5	133.7	32.0
AH32	1.5	1.5	134.2	28.4
AH41	1.5	1.5	143.5	31.9
AH42	1.5	1.5	141.7	29.9
AH51	1.5	1.5	116.1	28.4
AH61	1.5	1.5	143.7	35.4
AH71	1.5	1.5	117.8	18.7
AH81	1.5	1.5	137.8	28.2
AH91	5.0	1.5	129.4	24.6
AL11	1.5	1.5	125.3	23.6
AL21	1.5	1.5	103.5	14.4
AL31	1.5	1.5	102.7	15.0
AV11	1.5	1.5	118.7	20.2
AV21	1.5	1.5	107.5	14.8
AV31	1.5	1.5	106.0	15.3
AV32	1.5	1.5	106.4	16.6
AV33	1.5	1.5	106.0	15.8
AV41	1.5	1.5	106.0	15.0
AV51	1.5	1.5	100.3	13.2
AV61	1.5	1.5	101.1	13.5
AV71	1.5	1.5	99.8	14.7
AV72	1.5	1.5	98.7	13.3
AV81	1.5	1.5	98.6	13.3
AV91	1.5	1.5	99.1	13.5
AW11	1.5	1.5	133.0	25.2
AW21	1.5	1.5	106.1	14.9
AW31	1.5	1.5	99.8	13.6
AS11	1.5	1.5	117.4	23.5
AS21	1.5	1.5	113.8	22.0
AS31	5.0	1.5	115.1	19.3
AS41	1.5	1.5	110.2	17.5
AS42	1.5	1.5	113.2	20.1
AM11	33.8	33.8	106.4	15.3
AM12	33.8	33.8	106.4	15.3
AM13	33.8	33.8	106.4	15.2
AM14	33.8	33.8	106.4	15.2
AM15	33.8	33.8	106.4	15.1
AM16	33.8	33.8	124.9	18.7
AM17	33.8	33.8	124.8	18.7
AM21	1.5	1.5	114.9	21.3
AM31	1.5	1.5	136.1	29.8
AG11	1.5	1.5	108.3	20.1
AG12	1.5	1.5	108.6	19.9
AF11	1.5	1.5	101.2	13.5
AF12	5.0	1.5	100.4	13.2
AF21	1.5	1.5	101.2	13.3
AF31	1.5	1.5	101.3	13.6
PH11	1.5	1.5	117.9	28.6
PH21	1.5	1.5	139.3	35.0
PL11	1.5	1.5	134.6	30.8
PM11	33.8	33.8	124.9	19.0
PM12	33.8	33.8	124.4	19.5
PM13	33.8	33.8	125.3	19.3
B011	1.5	1.5	114.3	23.2
B012	1.5	1.5	114.3	23.9
B013	1.5	1.5	117.7	24.2
B014	1.5	1.5	111.0	21.6
B021	1.5	1.5	112.6	20.3
B022	1.5	1.5	112.6	19.3
B023	1.5	1.5	113.2	20.1
B024	1.5	1.5	113.8	20.7
B031	1.5	1.5	113.3	22.3
B032	1.5	1.5	109.3	21.1
B033	1.5	1.5	108.5	20.1
B034	1.5	1.5	108.5	20.6
B041	1.5	1.5	122.5	27.3
B042	1.5	1.5	114.1	22.5
B043	1.5	1.5	120.0	24.3
B051	1.5	1.5	111.7	18.9
B052	1.5	1.5	108.9	18.0
B053	1.5	1.5	112.4	19.0
B054	1.5	1.5	111.5	19.3
B061	1.5	1.5	107.9	19.5
B062	1.5	1.5	110.0	19.0
B063	1.5	1.5	110.1	18.8
B064	1.5	1.5	110.8	19.5
B071	1.5	1.5	109.7	17.4
B072	1.5	1.5	110.6	16.8
B073	1.5	1.5	111.2	17.9
B074	1.5	1.5	112.2	18.3
B081	1.5	1.5	109.8	18.5
B082	1.5	1.5	107.5	17.3
B083	1.5	1.5	106.5	17.0
B084	1.5	1.5	109.1	18.1
B091	1.5	1.5	111.7	20.0
B092	1.5	1.5	108.6	18.2
B093	8.0	1.5	107.7	17.5
B094	1.5	1.5	109.8	18.5
B101	1.5	1.5	106.5	16.5
B102	1.5	1.5	106.5	16.3
B103	1.5	1.5	108.8	16.6
B104	1.5	1.5	107.2	17.0
B111	1.5	1.5	106.5	16.7
B112	1.5	1.5	106.8	16.5
B113	1.5	1.5	106.4	16.1
B114	1.5	1.5	106.5	16.3
B121	1.5	1.5	109.6	17.9
B122	1.5	1.5	106.5	17.1
B123	1.5	1.5	109.4	17.8
CF01	15.0	15.0	107.1	17.7
CF02	15.0	15.0	107.9	17.4
CF03	15.0	15.0	106.5	17.5
CF04	15.0	15.0	106.4	17.5
CF05	15.0	15.0	106.4	18.1
CP01	15.0	15.0	108.8	17.6
CP02	15.0	15.0	108.0	17.1
CP03	15.0	15.0	106.4	17.0
CP04	21.0	21.0	106.4	16.5
CP05	21.0	21.0	106.4	16.6
CP06	21.0	21.0	107.0	17.0
CS01	1.5	1.5	114.4	25.1
CS02	1.5	1.5	112.7	23.9
CS03	1.5	1.5	121.1	23.5
CS04	1.5	1.5	123.1	25.7
CS05	1.5	1.5	121.2	25.9
CS06	1.5	1.5	129.2	31.7
PP01	1.5	1.5	106.2	15.9
PP02	1.5	1.5	106.0	15.8
PP03	1.5	1.5	106.0	15.7
PP04	1.5	1.5	106.1	15.7
Standard			200	40

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

ASR ID	Worst Affected Height (mAG)		PM₁₀ Concentrations (µg/m³)
ASR ID	10^th Highest Daily Average	Annual Average	10^th Highest Daily Average	Annual Average
AH11	1.5	1.5	65.0	27.3
AH12	1.5	1.5	65.0	27.3
AH13	5.0	1.5	65.0	27.3
AH21	1.5	1.5	65.4	27.6
AH22	1.5	1.5	65.3	27.5
AH31	1.5	1.5	67.6	33.9
AH32	15.0	1.5	70.2	33.9
AH41	1.5	1.5	73.7	33.3
AH42	15.0	1.5	73.5	32.9
AH51	1.5	1.5	64.9	27.6
AH61	1.5	1.5	64.8	27.7
AH71	1.5	1.5	64.7	27.3
AH81	1.5	1.5	65.6	31.9
AH91	1.5	1.5	76.1	33.5
AL11	1.5	1.5	72.5	33.0
AL21	1.5	1.5	65.1	27.2
AL31	1.5	1.5	65.2	27.2
AV11	1.5	1.5	65.3	27.4
AV21	5.0	1.5	64.8	27.2
AV31	5.0	1.5	65.0	27.3
AV32	1.5	1.5	65.1	27.3
AV33	1.5	1.5	65.0	27.3
AV41	5.0	1.5	64.9	27.2
AV51	1.5	1.5	65.0	27.1
AV61	1.5	1.5	65.1	27.2
AV71	1.5	1.5	65.1	27.2
AV72	5.0	1.5	65.1	27.2
AV81	1.5	1.5	65.1	27.2
AV91	1.5	1.5	65.1	27.2
AW11	1.5	1.5	87.7	42.9
AW21	1.5	1.5	64.9	27.2
AW31	1.5	1.5	65.1	27.2
AS11	1.5	1.5	65.2	27.5
AS21	1.5	1.5	65.3	27.4
AS31	1.5	1.5	65.1	27.4
AS41	1.5	1.5	65.2	27.3
AS42	1.5	1.5	65.3	27.4
AM11	33.8	33.8	64.8	27.3
AM12	33.8	33.8	64.8	27.3
AM13	33.8	33.8	64.8	27.3
AM14	33.8	33.8	64.8	27.3
AM15	33.8	33.8	64.8	27.3
AM16	33.8	33.8	66.4	33.5
AM17	33.8	33.8	66.9	33.9
AM21	1.5	1.5	65.2	27.4
AM31	1.5	1.5	78.0	39.7
AG11	1.5	1.5	65.2	27.4
AG12	1.5	1.5	65.2	27.4
AF11	1.5	1.5	65.1	27.2
AF12	1.5	1.5	65.0	27.1
AF21	1.5	1.5	65.1	27.2
AF31	5.0	1.5	65.1	27.2
PH11	1.5	1.5	64.9	27.7
PH21	1.5	1.5	66.5	28.6
PL11	1.5	1.5	66.8	28.4
PM11	33.8	33.8	65.6	27.9
PM12	33.8	33.8	65.7	27.9
PM13	33.8	33.8	65.7	27.9
B011	69.6	1.5	65.4	27.6
B012	69.6	1.5	65.5	27.6
B013	1.5	1.5	65.6	27.6
B014	1.5	1.5	65.3	27.5
B021	1.5	1.5	65.2	27.5
B022	1.5	1.5	65.2	27.4
B023	1.5	1.5	65.2	27.4
B024	1.5	1.5	65.2	27.5
B031	1.5	1.5	65.5	27.5
B032	1.5	1.5	65.4	27.5
B033	1.5	1.5	65.3	27.5
B034	1.5	1.5	65.2	27.5
B041	1.5	1.5	65.7	27.7
B042	1.5	1.5	65.4	27.5
B043	1.5	1.5	65.6	27.6
B051	1.5	1.5	65.2	27.4
B052	1.5	1.5	65.2	27.4
B053	1.5	1.5	65.2	27.4
B054	1.5	1.5	65.2	27.4
B061	1.5	1.5	65.3	27.4
B062	1.5	1.5	65.3	27.4
B063	1.5	1.5	65.3	27.4
B064	1.5	1.5	65.3	27.5
B071	1.5	1.5	65.1	27.4
B072	1.5	1.5	65.1	27.3
B073	1.5	1.5	65.1	27.4
B074	1.5	1.5	65.2	27.4
B081	1.5	1.5	65.3	27.4
B082	1.5	1.5	65.2	27.3
B083	1.5	1.5	65.2	27.3
B084	1.5	1.5	65.3	27.4
B091	1.5	1.5	65.3	27.4
B092	1.5	1.5	65.2	27.3
B093	1.5	1.5	65.2	27.3
B094	1.5	1.5	65.3	27.4
B101	1.5	1.5	65.1	27.3
B102	1.5	1.5	65.1	27.3
B103	1.5	1.5	65.1	27.3
B104	1.5	1.5	65.1	27.3
B111	1.5	1.5	65.1	27.3
B112	1.5	1.5	65.1	27.3
B113	1.5	1.5	65.1	27.3
B114	1.5	1.5	65.1	27.3
B121	1.5	1.5	65.2	27.4
B122	1.5	1.5	65.1	27.3
B123	1.5	1.5	65.2	27.4
CF01	15.0	15.0	65.1	27.3
CF02	15.0	15.0	65.1	27.3
CF03	15.0	15.0	65.1	27.3
CF04	15.0	15.0	65.1	27.3
CF05	15.0	15.0	65.1	27.4
CP01	15.0	15.0	65.1	27.3
CP02	15.0	15.0	65.1	27.3
CP03	15.0	15.0	65.1	27.3
CP04	21.0	21.0	65.0	27.3
CP05	21.0	21.0	65.0	27.3
CP06	21.0	21.0	65.0	27.3
CS01	1.5	1.5	65.5	27.6
CS02	1.5	1.5	65.4	27.6
CS03	1.5	1.5	65.4	27.6
CS04	1.5	1.5	65.6	27.7
CS05	1.5	1.5	65.6	27.7
CS06	1.5	1.5	65.9	27.9
PP01	1.5	1.5	65.1	27.3
PP02	1.5	1.5	65.0	27.3
PP03	1.5	1.5	65.0	27.3
PP04	1.5	1.5	65.0	27.3
Standard			100	50

Table 3.9.3 Predicted PM_2.5 Concentration at Worst Affected Level of ASRs – Operation Phase

ASRs	Worst Affected Height, mAG			PM_2.5 Concentrations (µg/m³)
ASRs	36th Highest Daily Average Conc.	19th Highest Daily Average Conc.	Annual Average Conc.	36th Highest Daily Average Conc.	19th Highest Daily Average Conc.	Annual Average Conc.
AH11	5.0	1.5	1.5	25.2	36.1	15.7
AH12	1.5	1.5	1.5	25.3	36.1	15.7
AH13	1.5	1.5	1.5	25.2	36.1	15.7
AH21	1.5	75.0	1.5	25.5	36.4	16.0
AH22	1.5	1.5	1.5	25.4	36.3	15.9
AH31	1.5	1.5	1.5	26.1	36.1	16.4
AH32	1.5	1.5	1.5	25.9	35.9	16.3
AH41	1.5	1.5	1.5	25.9	35.8	16.4
AH42	1.5	1.5	1.5	25.8	35.8	16.3
AH51	1.5	1.5	1.5	25.7	36.4	16.0
AH61	1.5	1.5	1.5	25.9	36.4	16.0
AH71	1.5	1.5	1.5	25.3	36.0	15.7
AH81	1.5	1.5	1.5	25.6	35.7	16.3
AH91	1.5	1.5	1.5	25.9	36.1	16.1
AL11	1.5	1.5	1.5	25.8	36.0	16.1
AL21	1.5	1.5	1.5	24.4	36.1	15.3
AL31	1.5	1.5	1.5	24.5	36.2	15.3
AV11	1.5	1.5	1.5	25.3	36.3	15.8
AV21	1.5	1.5	1.5	25.2	36.0	15.6
AV31	1.5	1.5	1.5	25.2	36.1	15.6
AV32	1.5	1.5	1.5	25.3	36.2	15.7
AV33	1.5	1.5	1.5	25.3	36.2	15.7
AV41	1.5	5.0	1.5	25.2	36.1	15.6
AV51	1.5	1.5	1.5	24.4	36.1	15.3
AV61	1.5	1.5	1.5	24.4	36.1	15.3
AV71	1.5	1.5	1.5	24.5	36.2	15.3
AV72	1.5	1.5	1.5	24.4	36.1	15.3
AV81	1.5	1.5	1.5	24.4	36.1	15.3
AV91	1.5	1.5	1.5	24.4	36.1	15.3
AW11	1.5	1.5	1.5	25.7	35.8	16.1
AW21	5.0	1.5	1.5	25.2	36.1	15.6
AW31	1.5	1.5	1.5	24.4	36.1	15.3
AS11	1.5	1.5	1.5	25.4	36.3	15.9
AS21	1.5	1.5	1.5	25.4	36.3	15.8
AS31	1.5	1.5	1.5	25.3	36.2	15.8
AS41	1.5	1.5	1.5	25.3	36.2	15.7
AS42	1.5	1.5	1.5	25.4	36.3	15.8
AM11	33.8	33.8	33.8	25.3	36.1	15.6
AM12	33.8	33.8	33.8	25.3	36.1	15.6
AM13	33.8	33.8	33.8	25.3	36.1	15.6
AM14	33.8	33.8	33.8	25.3	36.1	15.6
AM15	33.8	33.8	33.8	25.2	36.0	15.6
AM16	33.8	33.8	33.8	25.4	35.7	15.9
AM17	33.8	33.8	33.8	25.4	35.7	15.9
AM21	1.5	1.5	1.5	25.4	36.2	15.8
AM31	1.5	1.5	1.5	25.9	35.9	16.2
AG11	1.5	1.5	1.5	25.5	36.4	15.8
AG12	1.5	1.5	1.5	25.5	36.4	15.8
AF11	1.5	1.5	1.5	24.4	36.1	15.3
AF12	1.5	1.5	1.5	24.4	36.1	15.3
AF21	1.5	1.5	1.5	24.4	36.1	15.3
AF31	1.5	5.0	1.5	24.4	36.1	15.3
PH11	1.5	1.5	1.5	25.7	36.4	16.0
PH21	1.5	1.5	1.5	26.3	36.6	16.5
PL11	1.5	1.5	1.5	26.0	36.4	16.4
PM11	33.8	33.8	33.8	25.4	35.7	15.9
PM12	33.8	33.8	33.8	25.5	35.7	15.9
PM13	33.8	33.8	33.8	25.5	35.7	15.9
B011	1.5	1.5	1.5	25.6	36.5	15.9
B012	1.5	1.5	1.5	25.7	36.6	16.0
B013	1.5	1.5	1.5	25.7	36.6	16.0
B014	1.5	1.5	1.5	25.5	36.4	15.9
B021	1.5	1.5	1.5	25.5	36.4	15.8
B022	1.5	1.5	1.5	25.4	36.4	15.8
B023	1.5	1.5	1.5	25.4	36.4	15.8
B024	1.5	1.5	1.5	25.4	36.4	15.8
B031	1.5	1.5	1.5	25.6	36.5	15.9
B032	1.5	1.5	1.5	25.5	36.4	15.8
B033	1.5	1.5	1.5	25.5	36.4	15.8
B034	1.5	1.5	1.5	25.5	36.4	15.8
B041	1.5	1.5	1.5	25.8	36.6	16.0
B042	1.5	1.5	1.5	25.6	36.5	15.9
B043	1.5	1.5	1.5	25.6	36.6	16.0
B051	1.5	1.5	1.5	25.4	36.3	15.8
B052	1.5	1.5	1.5	25.3	36.3	15.8
B053	8.0	1.5	1.5	25.3	36.3	15.8
B054	8.0	1.5	1.5	25.4	36.3	15.8
B061	1.5	1.5	1.5	25.4	36.3	15.8
B062	1.5	1.5	1.5	25.4	36.3	15.8
B063	1.5	1.5	1.5	25.4	36.3	15.8
B064	1.5	1.5	1.5	25.4	36.4	15.8
B071	1.5	1.5	1.5	25.3	36.3	15.7
B072	1.5	1.5	1.5	25.3	36.2	15.7
B073	1.5	1.5	1.5	25.3	36.2	15.7
B074	1.5	1.5	1.5	25.3	36.3	15.8
B081	1.5	1.5	1.5	25.4	36.3	15.8
B082	1.5	1.5	1.5	25.3	36.2	15.7
B083	1.5	1.5	1.5	25.3	36.2	15.7
B084	1.5	1.5	1.5	25.3	36.3	15.8
B091	1.5	1.5	1.5	25.4	36.3	15.8
B092	1.5	1.5	1.5	25.3	36.2	15.7
B093	1.5	1.5	1.5	25.3	36.2	15.7
B094	1.5	1.5	1.5	25.3	36.3	15.8
B101	1.5	1.5	1.5	25.3	36.2	15.7
B102	1.5	1.5	1.5	25.3	36.2	15.7
B103	1.5	1.5	1.5	25.3	36.2	15.7
B104	1.5	1.5	1.5	25.3	36.2	15.7
B111	1.5	1.5	1.5	25.3	36.2	15.7
B112	1.5	1.5	1.5	25.3	36.2	15.7
B113	1.5	1.5	1.5	25.3	36.2	15.7
B114	1.5	1.5	1.5	25.3	36.2	15.7
B121	1.5	1.5	1.5	25.4	36.3	15.8
B122	1.5	1.5	1.5	25.3	36.2	15.7
B123	1.5	1.5	1.5	25.4	36.3	15.8
CF01	15.0	15.0	15.0	25.3	36.2	15.7
CF02	15.0	15.0	15.0	25.3	36.2	15.7
CF03	15.0	15.0	15.0	25.3	36.2	15.7
CF04	15.0	15.0	15.0	25.3	36.2	15.7
CF05	15.0	15.0	15.0	25.4	36.2	15.7
CP01	15.0	15.0	15.0	25.3	36.2	15.7
CP02	15.0	15.0	15.0	25.3	36.2	15.7
CP03	15.0	15.0	15.0	25.3	36.2	15.7
CP04	21.0	21.0	21.0	25.3	36.2	15.7
CP05	21.0	21.0	21.0	25.3	36.2	15.7
CP06	21.0	21.0	21.0	25.3	36.2	15.7
CS01	1.5	1.5	1.5	25.8	36.6	16.0
CS02	1.5	1.5	1.5	25.7	36.5	16.0
CS03	1.5	1.5	1.5	25.6	36.5	15.9
CS04	1.5	1.5	1.5	25.8	36.7	16.0
CS05	1.5	1.5	1.5	25.8	36.6	16.0
CS06	1.5	1.5	1.5	26.2	36.9	16.3
PP01	1.5	1.5	1.5	25.3	36.2	15.7
PP02	1.5	1.5	1.5	25.3	36.2	15.7
PP03	1.5	1.5	1.5	25.3	36.2	15.7
PP04	1.5	1.5	1.5	25.3	36.2	15.7
Standard				50	50	25
Note: [1] Proposed new AQO to be implemented in 2022

3.9.2 Based on the predicted results, all ASRs are predicted to meet the AQOs.

Incremental Air Quality Impact

3.9.3 The maximum concentration difference between “with” and “without” Project scenarios at existing/planned ASRs outside of the Project Site among all floors of each ASR are summarised in Table 3.9.4, Table 3.9.5 and Table 3.9.6 below. Details of results of “without” Project scenario and the difference between the two scenarios are presented in Appendix 3.14 and Appendix 3.15 respectively.

Table 3.9.4 Predicted NO₂ Concentrations under With and Without Project Scenarios

ASR ID	NO₂ Concentrations (µg/m³) – With Project		NO₂ Concentrations (µg/m³) – Without Project		Differences in NO₂ Concentrations (µg/m³) (With – Without)^{[Note 1]}
ASR ID	19^th Highest Hourly Averaged	Annual Averaged	19^th Highest Hourly Averaged	Annual Averaged	19^th Highest Hourly Averaged	Annual Averaged
AH11	114.3	17.7	113.7	17.2	5.8	0.4
AH12	112.5	17.4	112.5	17.0	4.6	0.4
AH13	114.2	17.6	114.1	17.4	2.4	0.2
AH21	125.9	24.9	112.3	19.7	13.6	5.2
AH22	117.7	22.8	109.4	19.8	8.7	3.0
AH31	133.7	32.0	121.6	17.9	12.1	14.1
AH32	134.2	28.4	124.7	18.9	13.5	10.1
AH41	143.5	31.9	124.6	17.2	22.0	14.7
AH42	141.7	29.9	124.7	17.3	22.4	12.8
AH51	116.1	28.4	115.0	28.0	1.1	0.4
AH61	143.7	35.4	143.8	35.2	2.0	0.2
AH71	117.8	18.7	117.4	18.4	0.7	0.3
AH81	137.8	28.2	121.6	17.9	16.2	10.8
AH91	129.4	24.6	118.2	17.5	11.6	7.4
AL11	125.3	23.6	117.8	17.2	7.6	6.4
AL21	103.5	14.4	103.4	14.3	0.7	<0.1
AL31	102.7	15.0	102.3	14.9	0.4	0.1
AV11	118.7	20.2	117.3	19.2	1.4	1.0
AV21	107.5	14.8	106.4	14.6	1.0	0.2
AV31	106.0	15.3	105.7	15.0	0.3	0.3
AV32	106.4	16.6	106.0	16.1	1.0	0.5
AV33	106.0	15.8	105.7	15.6	0.3	0.3
AV41	106.0	15.0	105.9	14.7	0.1	0.2
AV51	100.3	13.2	100.2	13.1	0.1	<0.1
AV61	101.1	13.5	101.1	13.4	<0.1	<0.1
AV71	99.8	14.7	99.8	14.7	<0.1	<0.1
AV72	98.7	13.3	98.7	13.3	<0.1	<0.1
AV81	98.6	13.3	98.6	13.2	<0.1	<0.1
AV91	99.1	13.5	99.1	13.4	<0.1	<0.1
AW11	133.0	25.2	124.6	18.8	9.2	6.4
AW21	106.1	14.9	105.9	14.7	0.2	0.2
AW31	99.8	13.6	99.8	13.6	<0.1	<0.1
AS11	117.4	23.5	110.6	19.0	8.3	4.5
AS21	113.8	22.0	109.3	18.7	5.5	3.3
AS31	115.1	19.3	114.3	18.7	4.3	0.6
AS41	110.2	17.5	107.7	16.8	2.8	0.7
AS42	113.2	20.1	112.4	19.3	4.8	0.8
AM11	106.4	15.3	106.4	15.1	<0.1	0.2
AM12	106.4	15.3	106.4	15.1	<0.1	0.2
AM13	106.4	15.2	106.4	15.0	<0.1	0.2
AM14	106.4	15.2	106.4	15.0	<0.1	0.2
AM15	106.4	15.1	106.4	14.9	<0.1	0.2
AM16	124.9	18.7	117.8	17.1	7.2	1.6
AM17	124.8	18.7	117.8	17.1	7.1	1.7
AM21	114.9	21.3	112.9	20.0	3.6	1.3
AM31	136.1	29.8	130.4	23.5	8.3	6.3
AG11	108.3	20.1	106.4	18.6	1.9	1.5
AG12	108.6	19.9	107.7	19.1	0.9	0.8
AF11	101.2	13.5	101.2	13.4	<0.1	<0.1
AF12	100.4	13.2	100.2	13.1	0.2	<0.1
AF21	101.2	13.3	101.2	13.3	<0.1	<0.1
AF31	101.3	13.6	100.9	13.5	0.4	<0.1
PH11	117.9	28.6	116.7	28.0	3.7	0.5
PH21	139.3	35.0	117.8	17.2	21.5	17.9
PL11	134.6	30.8	117.8	17.5	16.8	13.2
PM11	124.9	19.0	117.8	17.1	7.1	1.9
PM12	124.4	19.5	117.8	17.4	6.6	2.0
PM13	125.3	19.3	117.8	17.2	7.5	2.1

Note:

(1) The maximum differences between with and without project scenarios are underlined.

Table 3.9.5 Predicted PM₁₀ Concentration under With and Without Project Scenarios

ASR ID	PM₁₀ Concentrations (µg/m³) – With Project		PM₁₀ Concentrations (µg/m³) – Without Project		Differences in PM₁₀ Concentrations (µg/m³) (With – Without)
ASR ID	10^th Highest Daily Averaged	Annual Averaged	10^th Highest Daily Averaged	Annual Averaged	10^th Highest Daily Averaged	Annual Averaged
AH11	65.0	27.3	64.9	27.3	<0.1	<0.1
AH12	65.0	27.3	65.0	27.3	<0.1	<0.1
AH13	65.0	27.3	65.0	27.3	<0.1	<0.1
AH21	65.4	27.6	65.2	27.4	0.2	0.2
AH22	65.3	27.5	65.2	27.4	0.2	<0.1
AH31	67.6	33.9	67.5	33.8	0.1	0.1
AH32	70.2	33.9	70.1	33.8	<0.1	<0.1
AH41	73.7	33.3	73.7	33.3	<0.1	<0.1
AH42	73.5	32.9	73.5	32.8	<0.1	<0.1
AH51	64.9	27.6	64.8	27.6	<0.1	<0.1
AH61	64.8	27.7	64.8	27.7	<0.1	<0.1
AH71	64.7	27.3	64.7	27.3	<0.1	<0.1
AH81	65.6	31.9	65.6	31.8	<0.1	<0.1
AH91	76.1	33.5	76.1	33.5	<0.1	<0.1
AL11	72.5	33.0	72.5	32.9	<0.1	<0.1
AL21	65.1	27.2	65.1	27.2	<0.1	<0.1
AL31	65.2	27.2	65.2	27.2	<0.1	<0.1
AV11	65.3	27.4	65.2	27.4	0.1	<0.1
AV21	64.8	27.2	64.8	27.2	<0.1	<0.1
AV31	65.0	27.3	64.9	27.2	<0.1	<0.1
AV32	65.1	27.3	65.0	27.3	<0.1	<0.1
AV33	65.0	27.3	65.0	27.3	<0.1	<0.1
AV41	64.9	27.2	64.8	27.2	<0.1	<0.1
AV51	65.0	27.1	65.0	27.1	<0.1	<0.1
AV61	65.1	27.2	65.1	27.2	<0.1	<0.1
AV71	65.1	27.2	65.1	27.2	<0.1	<0.1
AV72	65.1	27.2	65.1	27.2	<0.1	<0.1
AV81	65.1	27.2	65.0	27.2	<0.1	<0.1
AV91	65.1	27.2	65.1	27.2	<0.1	<0.1
AW11	87.7	42.9	87.6	42.9	<0.1	<0.1
AW21	64.9	27.2	64.9	27.2	<0.1	<0.1
AW31	65.1	27.2	65.1	27.2	<0.1	<0.1
AS11	65.2	27.5	65.1	27.4	0.2	0.1
AS21	65.3	27.4	65.1	27.4	0.1	<0.1
AS31	65.1	27.4	65.1	27.4	<0.1	<0.1
AS41	65.2	27.3	65.1	27.3	<0.1	<0.1
AS42	65.3	27.4	65.2	27.4	<0.1	<0.1
AM11	64.8	27.3	64.8	27.3	<0.1	<0.1
AM12	64.8	27.3	64.8	27.3	<0.1	<0.1
AM13	64.8	27.3	64.8	27.3	<0.1	<0.1
AM14	64.8	27.3	64.8	27.3	<0.1	<0.1
AM15	64.8	27.3	64.8	27.3	<0.1	<0.1
AM16	66.4	33.5	66.4	33.5	<0.1	<0.1
AM17	66.9	33.9	66.8	33.9	<0.1	<0.1
AM21	65.2	27.4	65.1	27.4	0.1	<0.1
AM31	78.0	39.7	78.0	39.6	<0.1	<0.1
AG11	65.2	27.4	65.1	27.4	<0.1	<0.1
AG12	65.2	27.4	65.1	27.4	<0.1	<0.1
AF11	65.1	27.2	65.1	27.2	<0.1	<0.1
AF12	65.0	27.1	65.0	27.1	<0.1	<0.1
AF21	65.1	27.2	65.1	27.2	<0.1	<0.1
AF31	65.1	27.2	65.1	27.2	<0.1	<0.1
PH11	64.9	27.7	64.9	27.6	<0.1	<0.1
PH21	66.5	28.6	66.5	28.6	<0.1	<0.1
PL11	66.8	28.4	66.5	28.2	0.3	0.2
PM11	65.6	27.9	65.6	27.9	<0.1	<0.1
PM12	65.7	27.9	65.7	27.9	<0.1	<0.1
PM13	65.7	27.9	65.7	27.9	<0.1	<0.1

Note:

(1) The maximum differences between with and without project scenarios are underlined.

Table 3.9.6 Predicted PM_2.5 Concentration under With and Without Project Scenarios

ASR ID	PM_2.5 Concentrations (µg/m³) – With Project		PM_2.5 Concentrations (µg/m³) – Without Project		Differences in PM_2.5 Concentrations (µg/m³) (With – Without)
ASR ID	19^th Highest Daily Averaged	Annual Averaged	19^th Highest Daily Averaged	Annual Averaged	19^th Highest Daily Averaged	Annual Averaged
AH11	36.1	15.7	36.1	15.7	<0.1	<0.1
AH12	36.1	15.7	36.1	15.7	<0.1	<0.1
AH13	36.1	15.7	36.1	15.7	<0.1	<0.1
AH21	36.4	16.0	36.4	15.8	<0.1	0.2
AH22	36.3	15.9	36.2	15.8	<0.1	<0.1
AH31	36.1	16.4	36.0	16.3	0.1	<0.1
AH32	35.9	16.3	35.8	16.2	<0.1	<0.1
AH41	35.8	16.4	35.8	16.4	<0.1	<0.1
AH42	35.8	16.3	35.8	16.3	<0.1	<0.1
AH51	36.4	16.0	36.4	16.0	<0.1	<0.1
AH61	36.4	16.0	36.4	16.0	<0.1	<0.1
AH71	36.0	15.7	36.0	15.7	<0.1	<0.1
AH81	35.7	16.3	35.7	16.2	<0.1	<0.1
AH91	36.1	16.1	36.1	16.1	<0.1	<0.1
AL11	36.0	16.1	36.0	16.1	<0.1	<0.1
AL21	36.1	15.3	36.1	15.3	<0.1	<0.1
AL31	36.2	15.3	36.2	15.3	<0.1	<0.1
AV11	36.3	15.8	36.2	15.8	<0.1	<0.1
AV21	36.0	15.6	36.0	15.6	<0.1	<0.1
AV31	36.1	15.6	36.1	15.6	<0.1	<0.1
AV32	36.2	15.7	36.2	15.7	<0.1	<0.1
AV33	36.2	15.7	36.1	15.7	<0.1	<0.1
AV41	36.1	15.6	36.1	15.6	<0.1	<0.1
AV51	36.1	15.3	36.1	15.3	<0.1	<0.1
AV61	36.1	15.3	36.1	15.3	<0.1	<0.1
AV71	36.2	15.3	36.2	15.3	<0.1	<0.1
AV72	36.1	15.3	36.1	15.3	<0.1	<0.1
AV81	36.1	15.3	36.1	15.3	<0.1	<0.1
AV91	36.1	15.3	36.1	15.3	<0.1	<0.1
AW11	35.8	16.1	35.8	16.1	<0.1	<0.1
AW21	36.1	15.6	36.1	15.6	<0.1	<0.1
AW31	36.1	15.3	36.1	15.3	<0.1	<0.1
AS11	36.3	15.9	36.2	15.8	<0.1	0.1
AS21	36.3	15.8	36.3	15.7	<0.1	<0.1
AS31	36.2	15.8	36.1	15.7	<0.1	<0.1
AS41	36.2	15.7	36.2	15.7	<0.1	<0.1
AS42	36.3	15.8	36.3	15.8	<0.1	<0.1
AM11	36.1	15.6	36.1	15.6	<0.1	<0.1
AM12	36.1	15.6	36.1	15.6	<0.1	<0.1
AM13	36.1	15.6	36.1	15.6	<0.1	<0.1
AM14	36.1	15.6	36.1	15.6	<0.1	<0.1
AM15	36.0	15.6	36.0	15.6	<0.1	<0.1
AM16	35.7	15.9	35.7	15.9	<0.1	<0.1
AM17	35.7	15.9	35.7	15.9	<0.1	<0.1
AM21	36.2	15.8	36.2	15.8	<0.1	<0.1
AM31	35.9	16.2	35.9	16.2	<0.1	<0.1
AG11	36.4	15.8	36.3	15.8	0.1	<0.1
AG12	36.4	15.8	36.3	15.8	<0.1	<0.1
AF11	36.1	15.3	36.1	15.3	<0.1	<0.1
AF12	36.1	15.3	36.1	15.3	<0.1	<0.1
AF21	36.1	15.3	36.1	15.3	<0.1	<0.1
AF31	36.1	15.3	36.1	15.3	<0.1	<0.1
PH11	36.4	16.0	36.4	16.0	<0.1	<0.1
PH21	36.6	16.5	36.6	16.5	<0.1	<0.1
PL11	36.4	16.4	36.1	16.2	0.2	0.2
PM11	35.7	15.9	35.7	15.9	<0.1	<0.1
PM12	35.7	15.9	35.7	15.9	<0.1	<0.1
PM13	35.7	15.9	35.7	15.9	<0.1	<0.1

Note:

(1) The maximum differences between with and without project scenarios are underlined.

3.9.4 The maximum differences of in annual averaged NO₂, PM₁₀ and PM_2.5 on representative ASRs between with and without project scenarios are 17.9µg/m³, 0.2µg/m³ and 0.2µg/m³ respectively. For short term concentrations, the maximum differences between with and without project scenarios for 19^th highest hourly average NO₂ is 22.4µg/m³, 10^th highest daily average PM₁₀ and 19^th highest daily average PM_2.5 concentration is less than 0.3 µg/m³ and 0.2 µg/m³ respectively. Despite the incremental increase of pollutant concentration, the ASRs are still complied with the AQOs. No adverse residual air quality impact is anticipated at the ASRs with the Project.

Recommended Mitigation Measures

3.9.5 According to the results, no adverse cumulative air quality impact is anticipated. No mitigation measure is required.

Residual Impact

3.9.6 No adverse residual air quality impact during operational phase is anticipated.

3.10 Conclusion and Recommendations

Construction Phase

3.10.1 Major potential construction dust impact would be generated from site clearance, ground excavation and site formation during the construction phase. Quantitative construction dust impact assessment has been conducted. Results have concluded that there will not be any adverse residual air quality impact during construction phase with implementation of mitigation measures with 3m hoarding and watering on exposed worksites and haul road.

Operation Phase

3.10.2 Quantitative air quality assessment for operational phase has been conducted, taking into account the vehicular emission impact associated with the Project and existing road networks, industrial emission in the vicinity of the Project and the impacts from proposed and existing PTIs and proposed carparks. It is concluded that the predicted cumulative air quality impacts on all ASRs would comply with the AQOs during the operational phase of the Project.

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

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

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

· Air Pollution Control (Construction Dust) Regulation

· Air Pollution Control (Smoke) Regulation

· Air Pollution Control (Fuel Restriction) Regulation

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

· Recommended Pollution Control Clauses for Construction Contracts

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

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

Air Quality Objectives

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

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

Air Pollution Control (Construction Dust) Regulation

Air Pollution Control (Smoke) Regulation

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

Air Pollution Control (Fuel Restriction) Regulation

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

· Gaseous fuel

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

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

Total Suspended Particulate Criteria

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

Odour Level

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

3.3 Baseline Condition

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

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

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

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

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

Construction Phase

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

· Wind erosion of exposed open area.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Operation Phase

· Vehicular emissions from road networks within the assessment area;

· Chimney emissions from North District Hospital;

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

· Background pollutant concentrations.

Identification of Representative Air Pollutants of Vehicle Emissions

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

Identification of Representative Air Pollutants of Chimneys Emissions

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

Identification of Odour Impact

Dust Emission associated with the Project and other Sources

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

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

Methodology and Assumptions of Dispersion Model – Construction Activities

Dispersion Model

Meteorological Data

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

Model Approach

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

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

Unmitigated Scenario

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

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

Recommended Mitigation Measures

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

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

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

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

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

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

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

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

3.3.4 As per Guidelines on Choices of Models and Model Parameters as published by EPD, the PM₁₀ and PM_2.5 output of PATH should be adjusted as below.

· Annual average concentrations, PM₁₀ (+10.3µg/m³), PM_2.5 (+3.5 µg/m³)

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

3.3.5 The NO₂, PM₁₀, PM_2.5, SO₂ , O₃ and CO concentrations predicted by PATH in Year 2025 within the concerned grids are summarized in Table 3.3.2 below.

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

3.5.29 The fuel used by nearby chimneys emissions are towngas which is extremely low in sulphur content . Therefore, the concerned pollutants during operation phase are NO₂ and PM₁₀, PM_2.5.

3.7.1 The predicted TSP, PM₁₀ and PM_2.5 impact at the worst affected level arising from unmitigated construction activities are summarised in Table 3.7.1, Table 3.7.2 and Table 3.7.3. Details of predicted concentrations are shown in Appendix 3.3.

3.7.2 Exceedances of TSP standard were predicted amongst most of the representative ASRs. Annual averaged and daily averaged PM₁₀ and PM_2.5 objectives are exceeded at numbers of ASRs.