3                    Air Quality Impact ASSESSMENT

3.1              Introduction

3.1.1        This Chapter presents an air quality impact assessment for the construction and operational phases of the Project. By nature of their uses, the Main Stadium, the Public Sports Ground, the Indoor Sports Centre and the associated hotel and office blocks in this Project are also considered air sensitive receivers and the air quality impact on the future uses of these facilities is addressed in this Chapter.

3.1.2        The Project by itself is not an air pollutant source; however, the traffic induced by the operation of the Project may cause additional air quality impact on sensitive receivers along the traffic routes in the area. In this connection, apart from the air sensitive receivers within the boundary of the Project, the operational phase air quality assessment also covers all the existing, committed and planned sensitive receivers within the Study Area where air quality may be potentially affected by the Project. In accordance with Section 3.4.3.2 of the EIA Study Brief, the Study Area is defined by a distance of 500m from the boundary of the Project site, with consideration to be extended to include major existing, planned and committed air pollutant emission sources that may have a bearing on the environmental acceptability the Project. Figure 3-1 shows the Study Area for air quality impact assessment of the Project.

3.2              Environmental Legislation, Policies, Plans, Standards and Criteria

3.2.1        The criteria and guidelines for evaluating and assessing air quality impact are stated in Section 1 of Annex 4 and Annex 12 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM).

Air Pollution Control Ordinance

3.2.2        The Air Pollution Control Ordinance (Cap. 311) provides for the control of air pollutants from a variety of stationary and mobile sources through the establishment of a set of Air Quality Objectives (AQOs).  As of 1^st January 2014, a new set of air quality objectives which stipulates maximum concentrations for a range of pollutants, namely nitrogen dioxide (NO₂), sulphur dioxide (SO₂), respirable suspended particulates (RSP or PM₁₀), fine suspended particulates (FSP or PM_2.5), carbon monoxide (CO), photochemical oxidants (O₃) and lead (Pb) has been in force.  The AQOs are listed in Table 3-1 below.

Table 3‑1    Hong Kong Air Quality Objectives

Pollutant	Averaging time	Concentration limit [i] (μg/m3)	Number of exceedances allowed
Sulphur dioxide	10-minute	500	3
	24-hour	125	3
Respirable suspended particulates (PM10) [ii]	24-hour	100	9
	Annual	50	Not applicable
Fine suspended particulates (PM2.5) [iii]	24-hour	75	9
	Annual	35	Not applicable
Nitrogen dioxide	1-hour	200	18
	Annual	40	Not applicable
Ozone	8-hour	160	9
Carbon monoxide	1-hour	30,000	0
	8-hour	10,000	0
Lead	Annual	0.5	Not applicable

Note:

[i]                  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 293Kelvin and a reference pressure of 101.325 kilopascal.

[ii]                 Respirable suspended particulates means suspended particles in air with a nominal aerodynamic diameter of 10 μm or less.

[iii]                Fine suspended particulates means suspended particles in air with a nominal aerodynamic diameter of 2.5 μm or less.

3.2.3        For construction dust, Annex 4 of EIAO-TM specifies a TSP limit concentration averaged over a 1-hour period to be 500 µg/m³. Mitigation measures for construction sites have been specified in the Air Pollution Control (Construction Dust) Regulation (Cap. 311R). It also requires contractors and site agents to inform EPD and adopt dust reduction measures while carrying out “Notifiable Works” or “Regulatory Works” as defined under the regulation.  Works relevant to this Project include both “Notifiable Works” (site formation, construction of foundation and superstructure of a building) and “Regulatory Works” (stockpiling of dust materials, site clearance).

3.3              Identification of Key Air Pollution Parameters

Construction Phase

3.3.1        The major construction works of the Project would be piling, pile cap construction and backfilling, works for basement structures, superstructure, installation of steel frame and retractable roof of the Main Stadium, builder’s works, external works and landscaping works. During the construction phase of the Project,  dust would arise primarily from:

l    Heavy construction works (piling, pile cap construction, backfilling, basement construction and foundation); and

l    Wind erosion of open sites.

 

3.3.2        Dust emissions from stockpiling are considered as part of wind erosion of open sites for the whole construction site of the Project.

3.3.3        As all construction site vehicles must be washed at the entrance of the site before leaving and after arriving the site, dust emissions from construction vehicle movements out of the site should be insignificant. By adopting the heavy construction emission factor in USEPA AP-42 in the assessment which includes dust emissions from construction vehicle movements inside the construction site, no additional consideration of dust emissions from paved haul roads within the construction site is needed.

3.3.4        For the purpose of the construction dust assessment, 1-hour TSP, 24-hour RSP, annual RSP, 24-hour FSP and annual FSP concentrations have been adopted for the assessment.

Operational Phase

3.3.5        The Air Pollutant Control Ordinance (APCO) (Cap. 311) defines statutory Air Quality Objective (AQO) for 7 common air pollutants including NO₂, SO₂, RSP, FSP, CO, O₃ and lead. According to Appendix A of Section 5(ii) of the EIA Study Brief, representative air pollution parameters including types of pollutants and average time concentrations shall be determined.

3.3.6        The emission sources during the operational phase of the Project would be the vehicular emissions from both the new and existing roads. Nitrogen dioxide (NO₂), respirable suspended particulates (RSP), and fine suspended particulates (FSP) are the key criteria pollutants for assessment of the air quality impact in this Project. Apart from the vehicular emission sources, industrial chimneys and ventilation buildings within 1km from the boundary of project site, as well as the emissions from the To Kwa Wan Typhoon Shelter and Kai Tak Cruise Terminal are also emission sources for the assessment. Therefore, the AQOs for 1-hr NO₂, annual NO₂, 24-hr FSP, annual FSP, 24-hr RSP and annual RSP have been identified as key assessment criteria.

3.3.7        In Hong Kong, sulphur dioxide (SO₂) comes primarily from the combustion of sulphur-containing fossil fuels in power stations and marine vessels. A statutory requirement had been laid down since April 2002 to restrict vehicles to use ULSD (Ultra Low Sulphur Diesel) with a sulphur content of less than 0.005% and the requirement has been further tightened to a sulphur content of less than 0.001% from 1 July 2010 onward. Therefore, emission of SO₂ from vehicles is no longer a significant source. Although the Project is unlikely to contribute a significant amount of SO₂ to the environment, the SO₂ from industrial chimneys, the typhoon shelter and the cruise terminal in the vicinity may have an impact on the Project. Therefore, the AQOs for 10-min and 24-hr SO₂ are also identified as assessment criteria.

3.3.8        Carbon monoxide (CO) is one of the primary pollutants emitted by road transport. However, monitoring results from all of the EPD’s air quality monitoring stations show that background CO concentrations are consistently well below the respective criteria.  With respect to the compliance of the cumulative impact with the relevant AQO criteria, CO is therefore considered to be non-critical and it is not necessary to be quantitatively assessed. Ozone (O₃) is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges. It is not a primary pollutant in vehicular emissions and thus is not considered as a key criteria pollutant for this Project.

3.3.9        Leaded petrol had been banned in Hong Kong since 1999. As such, it is not considered a key pollutant in vehicular emissions.

3.3.10    To sum up, the following pollution sources are relevant during the operational phase and have been assessed in this Project:

                                i.            Background pollution concentrations;

                              ii.            Vehicle emissions from existing and proposed open road networks within 500 m from the site boundary;

                            iii.            Emissions from portals and ventilation buildings within 500m from the site boundary;

                            iv.            Emissions from To Kwa Wan Typhoon Shelter;

                              v.            Marine emissions from Kai Tak Cruise Terminal; and

                            vi.            Industrial chimneys within 1km from the site boundary.

3.4              Air Sensitive Receivers

3.4.1        In accordance with Annex 12 of the EIAO-TM, any domestic premises, hotel, hostel, hospital, clinic, nursery, temporary housing accommodation, school, educational institution, office, factory, shop, shopping centre, place of public worship, library, court of law, sports stadium or performing arts centre are considered as air sensitive receivers (ASRs).

3.4.2        In accordance with Section 3.4.3.2 of the EIA Study Brief, the air quality impact assessment area is defined by a distance of 500m from the boundary of the Project. The Study Area for air quality impact assessment in this Project is shown in Figure 3-1.

3.4.3        Based on the Project construction programme, the construction works shall start in 2017 for completion by 2020/2021. For the planned ASRs without any tentative schedule for completion under the latest Recommended Outline Development Plan (e.g. sub-planning area 2A, 2B, 1K, 1L), it has been assumed that the population intake at these ASRs would be after the completion year of the Project and hence no representative ASRs were selected for the construction phase impact assessment. Nevertheless, the air pollutant concentrations at the general locations of these planned ASRs within the Study Area are presented in the cumulative contour plots for both unmitigated and mitigated scenarios.

3.4.4        The identified ASRs within the Project site include the Main Stadium, Public Sports Ground, and the possible fresh air intake locations for the Indoor Sports Centre, offices and hotel.

3.4.5        ASRs located along the roads with traffic induced by the operation of the Project have been identified for evaluating the potential air quality impact due to the operation of the Project. The major traffic routes include Road D2, Sung Wong Toi Road, To Kwa Wan Road, Kowloon City Road, Shing Kai Road, Olympic Avenue and Prince Edward Road East, etc.

3.4.6        The assessment heights were taken at 1.5m, 5m, 10m, 20m above ground and so on up to the maximum building heights of the respective ASRs. The ASRs are listed in Table 3-2. Locations of ASRs in the construction phase and operational phase are shown in Figure 3-2A and Figure 3-2B respectively.

Table 3‑2    Summary of Air Sensitive Receivers

ASR ID	Location	Land Use[i]	Lowest Assessment Level	H[ii]	DC[iii]	DO[iii]	C[v]	O[vi]
	Prince Edward Road East  (Existing ASRs)
A1	Shek Ku Lung Road Playground	L	1.5	1.5	200	15	a	a
A2[vii]	Regal Hotel	R	20	40	300	8	a	a
A3	South Mansion	R	1.5	19	170	23	a	a
A4	Jenford Building	R	1.5	13	93	6	a	a
	Ma Tau Chung Road  (Existing ASRs)
A5	Holy Trinity Church	RE	1.5	12	-	10	r	a
A5a	Kam Wah Building	R	1.5	50	-	6	r	a
A6	Parc 22	R	1.5	33	200	8	a	a
A16	Sung Wong Toi Playground	L	1.5	1.5	117	7	a	a
	Ma Tau Kok Area/ Kowloon City Road (Kai Tak Tunnel West Portal) (Existing ASRs)
A7[vii]	Sky Tower	R	20	165	78	4	a	a
A11	Kam Tong Building	R	1.5	34	-	3	r	a
A12	Kowloon City Road No.179-183	R	1.5	16	-	4	r	a
A14	Mok Cheong Street Residential District	R	1.5	22	-	4	r	a
A15	Po Sing Mansion	R	1.5	36	-	5	r	a
	To Kwa Wan Area  (Existing ASRs)
A8[vi]	HK Society for Blind Hostel (facing To Kwa Wan Road)	R	5.0	9	-	7	r	a
A9	Mok Cheong Street Residential District	R	1.5	14	158	5	a	a
A10	Grand Water Front (facing To Kwa Wan Road)	R	1.5	171	-	5	r	a
A13	Mok Cheong Street Residential District	R	1.5	22	239	3	r	a
A17	Fire Station	G	1.5	10	31	-	a	r
A18	Lung To Street No.208	R	1.5	9	186	-	a	r
A19	HK Society for Blind Hostel (facing Project Site)	R	1.5	9	97	-	a	r
A20	Grand Water Front (facing Project Site)	R	1.5	171	54	-	a	r
	Kowloon Bay Area  (Existing ASRs)
A21	EMSD Headquarter	G	1.5	30	18	-	a	r
	To Kwa Wan Area  (Planned ASRs)
PA12	Sung Wong Toi Road CDA Site	MU	1.5	95	-	6	r	a
PA13 [vii]	Sung Wong Toi Road CDA Site	MU	10	95	-	11	r	a
PA14 [vii]	Sung Wong Toi Road R(A) Site	R	10	95	-	13	r	a
PA15	KTD Site 5A4	MU	1.5	105	-	14	r	a
PA16	KTD Site 5A4	MU	1.5	105	-	11	r	a
	Olympic Avenue (Planned ASRs) [vii]
PA3	KTD Site 1F2	C	1.5	195	-	34	r	a
PA4	KTD Site 1M1	C	1.5	35	-	15	r	a
PA5	KTD Site 2A1	CSU	1.5	115	-	27	r	a
PA6	KTD Site 2A2	CSU	1.5	95	-	26	r	a
PA7	KTD Site 2A2	CSU	1.5	95	-	37	r	a
PA8	KTD Site 2A3	CSU	1.5	95	-	14	r	a
PA9	KTD Site 2A4	CSU	1.5	95	-	17	r	a
PA10	KTD Site 2A5	CSU	1.5	75	-	16	r	a
PA11	KTD Site 2A7	C	1.5	75	-	11	r	a
	Kai Tak Development Area (Planned ASRs) [viii]
PA1	KTD Site 1L	R	1.5	100	30	-	a	r
PA2	KTD Site 1K	R	1.5	110	22	-	a	r
PA17	KTD Site 3B1	CSU	1.5	75	-	52	r	a
PA18	KTD Site 3A6	CSU	1.5	95	-	10	r	a
PA19	KTD Site 1N1	C	1.5	115	-	18	r	a
PA20	KTD Site 1N1	C	1.5	115	-	49	r	a
PA21	KTD Site 1K2	R	1.5	125	-	16	r	a
PA22	KTD Site 1L3	R	1.5	115	-	13	r	a
PA23	KTD Site 1L3	R	1.5	115	-	48	r	a
PA24	KTD Site 1L2	R	1.5	115	-	62	r	a
PA25	KTD Site 1I3	R	1.5	115	-	121	r	a
	MPSC (Planned ASRs)
ISC	Indoor Sports Centre-Middle	MU	1.5	35	-	176	r	a
ISE	Indoor Sports Centre-East	MU	1.5	35	-	113	r	a
ISN	Indoor Sports Centre-North	MU	1.5	35	-	193	r	a
ISS	Indoor Sports Centre-South	MU	1.5	35	-	109	r	a
ISW	Indoor Sports Centre-West	MU	1.5	35	-	172	r	a
MSC	Main Stadium-Middle	MU	1.5	70	-	170	r	a
MSE	Main Stadium-East	MU	1.5	70	-	133	r	a
MSN	Main Stadium-North	MU	1.5	70	-	120	r	a
MSS	Main Stadium-South	MU	1.5	70	-	86	r	a
MSW	Main Stadium-West	MU	1.5	70	-	153	r	a
PSC	Public Sports Ground-Middle	MU	1.5	30	-	103	r	a
PSE	Public Sports Ground-East	MU	1.5	30	-	75	r	a
PSN	Public Sports Ground-North	MU	1.5	30	-	207	r	a
PSS	Public Sports Ground-South	MU	1.5	30	-	28	r	a
PSW	Public Sports Ground-West	MU	1.5	30	-	135	r	a
OBN	Office Block	C	1.5	38	-	65	r	a
OBS	Office Block	C	1.5	38	-	73	r	a
HBN	Hotel Block	C	1.5	45	-	10	r	a
HBS	Hotel Block	C	1.5	45	-	39	r	a

Note:

[i]                            L – Leisure; R – Residential; G – Government; C – Commercial; MU – Mixed Use; RE – Religious/Place of Public Worship; CSU - Commercial with sensitive uses

[ii]                          Approximated Building Height Above ground (m)

[iii]                         D_C – separation distance of the ASRs from the nearest emission source during construction phase;

D_O –separation distance of the ASRs from the nearest emission source during operational phase.

[iv]                        Assessed during Construction Phase

[v]                          Assessed during Operational Phase

[vi]                        This ASR will be re-built with a new layout. The operational phase assessment will adopt the façade closest to the road as sensitive receiver.

[vii]                       The air intakes / sensitive use for these buildings would be above podium level.

[viii]                     The description for the ASRs under the ASR group of “Olympic Avenue” and “Kai Tak Development Area” are the site reference number in the Recommended Outline Development Plan.

3.5              Projected Background Air Quality Result of Year 2020 by PATH Model

3.5.1        The 500 m Study Area covers 4 grids of the PATH model, including grids (30, 28), (30, 29), (31, 28) and (31, 29). A summary of the projected background concentrations in Year 2020 is shown in Table 3-3. It shows that SO₂, RSP, FSP and NO₂ comply with the AQOs after considering the number of exceedances allowed.

Table 3‑3    Summary of Predicted Results from PATH Model in Year 2020

Pollutant	Averaging Time	AQOs [µg/m3]	PATH Model Concentration [µg/m3]
			Grid [30, 28]	Grid [30, 29]	Grid [31, 28]	Grid [31, 29]
Sulphur dioxide [ii]	10-minute (4th High)	500 (3)	113 [0]	102 [0]	102 [0]	94 [0]
	24-hour (4th High)	125 (3)	23 [0]	22 [0]	22 [0]	21 [0]
RSP [PM10] [iii]	24-hour (10th High)	100 (9)	79 [1]	75 [1]	76 [1]	75 [1]
	Annual	50	42	40	40	40
FSP [PM2.5] [iv]	24-hour (10th High)	75 (9)	60 [1]	56 [1]	57 [1]	57 [1]
	Annual	35	30	28	29	28
NO2	1-hour (19th High)	200	182 [6]	162 [4]	169 [7]	148 [3]
	Annual	40	28	25	25	22

Note:  

[i]         The number in brackets () refers to number of exceedance allowed per year.

[ii]        The number in brackets [] refers to number of exceedances of the background concentration.

[iii]       The predicted 4^th highest 10-minute SO₂ concentrations presented were calculated by multiplying the predicted maximum hourly SO₂ concentrations by the stability-dependent multiplicative factors. So that, the predicted 4^th highest 10-minute SO₂ concentration is equal to the predicted maximum 10-minute SO₂ concentration.

[iv]       FSP concentrations were estimated from RSP concentrations.

 

3.6              Sensitivity Test for Determination of the Worst Assessment Year

Construction Phase

3.6.1        The construction works of the Project are scheduled to commence in 2017 for completion in 2020/2021. The main heavy works (piling, pile cap construction and backfilling & basement structures construction) will take place from the second quarter of 2017 to the first quarter of 2018. Therefore, 2017 has been adopted as the worst assessment year for the construction dust impact assessment.

Operational Phase

3.6.2        In accordance with the EIA Study Brief (No. ESB-274/2014), the air quality impacts of the Project should be assessed based on the highest emission strength from the roads within the next 15 years upon commissioning of the Project. The selected year of assessment shall represent the highest emission scenario given the combination of vehicular emission factors and traffic flows for the selected year.

3.6.3        Construction of the Project is planned to be completed and commissioned in 2020/2021. Since the air quality impacts of future road traffic should be calculated based on the highest emission strength within the next 15 years upon operation of the Project, four representative years – 2021, 2023, 2026 and 2036 were chosen for a sensitivity test. Due to possible delay of the construction program of the Central Kowloon Route (CKR) the works for the CKR is expected to be commissioned by 2023. Therefore, CKR was excluded in the 2021 scenario. EMFAC-HK was employed to estimate the emissions of the existing and proposed roads for future years and the traffic forecasts for 2021 (without CKR), 2023, 2026 and 2036 provided by Project Traffic Consultant were used as input to the model to predict emissions. Details of the assumptions in EMFAC-HK are shown in Appendix 3.2.

3.6.4        According to “2010 Hong Kong Emission Inventory Report” published by EPD, tailpipe emissions are the largest source of NO₂ besides navigation. Hence, NO₂ was identified as the key pollutant in determining the emission strengths of future scenario. The result of the sensitivity test showed that the worst assessment year will occur in 2023. Detailed results are shown in Appendix 3.2.

3.7              Construction Phase Assessment

3.7.1        This section addresses the construction dust impact through a quantitative assessment approach to evaluate the potential impact on the identified ASRs in accordance with the requirement in Section 3 of Appendix A of the EIA Study Brief.

Assessment Methodology

3.7.2        The assessment of air quality impact in construction phase follows the detailed technical requirements in the EIA Study Brief. The “Pollutants in the Atmosphere and their Transport over Hong Kong (PATH)” model was used to predict the future background concentrations of air pollutants. Fugitive Dust Model (FDM) was employed to predict the concentrations of air pollutants at the identified ASRs due to emissions from the construction works of this project and concurrent construction works within the study area.

3.7.3        The assessment adopted the 1-hour TSP, 24-hour RSP, annual RSP, 24-hour FSP and annual FSP concentrations as air quality parameters.

Emission Inventory of Dust Emission from Construction Activities

3.7.4        A computational model, FDM, was used to assess the potential dust impact during the construction phase. It is an EPD approved Gaussian Plume model designed for computing air dispersion from fugitive dust sources.

3.7.5        Values for the modelling parameters, including dust emission factors, particles size distributions, surface roughness were obtained from EPD’s “Guideline on choice of models and model parameters” and USEPA AP-42. The surface roughness is closely related to the land use characteristics of a study area and associated with the roughness element height. The sea roughness and urban roughness are assumed to be 0.01 cm and 370 cm, respectively.  The area averaged surface roughnesses were taken as 370cm, 259cm, 370cm and 222cm for four PATH grids (30, 28), (30, 29), (31, 28) and (31, 29), respectively.  The density of the dust was assumed to be 2.5 g/m³.

3.7.6        Hourly meteorological data for a full year were extracted from the PATH model in grids (30, 28), (30, 29), (31, 28) and (31, 29) and have been adopted for use in FDM. The stability classes were obtained from a separate model, i.e. PCRAMMET. The minimum mixing height of 121m was adopted from the Hong Kong Observatory in 2010.

3.7.7        According to Section 13.2.3.3 of USEPA AP-42, the emission factor for a typical heavy construction activity is 2.69 Mg/hectare/month. The number of working days for a month and number of working hours per day of the project are anticipated to be 26 days and 12 hours respectively. No construction works are anticipated to be carried out on Sundays. From Table 11.9-4 of USEPA AP-42, the emission factor of wind erosion is 0.85 Mg/hectare/year. The emission factors are listed in Table 3-4.

Table 3‑4    Emission Factors for Dusty Construction Activities

Emission Source	Activity	Emission Rate (E) (Mg/hectare/month)	Remarks
Piling, Pile Cap Construction and backfilling & basement structures construction for the Project	Heavy Construction Activities	TSP E=2.69[i] RSP E=2.69 × 30%[ii]   FSP E=2.69 × 3% [iii]	100% area actively operating 26 days/month, 12 hours/day
	Wind Erosion	TSP E=0.85[iv] RSP E=0.85 × 30%[ii] FSP E=0.85 × 3%[iii]	100% area actively operating 26 days/month, 12 hours/day

Notes:

[i]              Section 13.2.3.3 of USEPA AP-42, 5^th Edition

[ii]             USEPA document Estimating Particulate Matter Emissions from Construction Operations, 1999

[iii]           Thompson G. Pace, USEPA. Examination of the Multiplier Used to Estimate PM_2.5 Fugitive Dust Emissions from PM₁₀, April 2005

[iv]           Table 11.9-4 of USEPA AP-42, 5^th Edition

 

3.7.8        As a conservative approach, the active construction area was assumed to be 100% of the Project site for both the short term (hourly and daily) and long term (annual) assessment.

3.7.9        In the mitigated scenario, the active construction areas would have ground watering applied every hour during the works. The adopted dust suppression is 91.7% and is shown in Appendix 3.1. The unmitigated scenario does not have any watering for dust suppression.

Potential Concurrent Projects

3.7.10    In order to assess the cumulative construction dust impact, the following concurrent construction sites were also included in this assessment:

·                East Portion of Central Kowloon Route (CKR, planned to be completed in 2021 but with possible delay of 2 years based on the latest information),

·                Reconstruction and Upgrading of Kai Tak Nullah (planned to be completed in April 2018),

·                Kai Tak Development Stage 4 (Road D2 construction) (Planned to be completed in 3^rd quarter of 2017),

·                North Apron Remaining Infrastructure (planned to be completed in late 2021),

·                Kai Tak Approach Channel and Kwun Tong Typhoon Shelter Improvement Works (Phase 2) (planned to be completed in December 2018), and

·                Shatin Central Link (SCL planned to be completed in 2019 due to delay).

3.7.11    Based on the current construction works programme of Shatin Central Link, the heavy construction works shall be completed by 2016. Hence, dust emission contribution from SCL during the Project construction work period should be insignificant and thus was not considered in the cumulative impact assessment.  On the other hand, construction works for some projects have commenced at the time of this EIA Study, and some of the works should have been completed before commencement of the Project. In this case, only the outstanding portions of the work sites were considered in this assessment.

3.7.12    Portions of the works sites of Kai Tak Approach Channel and Kwun Tong Typhoon Shelter Improvement Works (Phase 2) that are within the 500m Study Area of the Project were also included for the assessment as typical heavy construction activity. The works zone and corresponding emission strengths for those concurrent projects were based on the approved EIA reports as mentioned in Section 3.7.10 with updated project programme. Details of the emission factors for all concurrent projects are listed in Appendix 3.1 and the locations of dust sources are shown in Figure 3-3.

Background Air Quality

3.7.13    PATH is a macro-scale air quality model developed by EPD to predict future air quality over the whole Pearl River Delta region including Hong Kong. Currently, the nearest background air quality prediction from the assessment year (2017) is 2015. It was therefore adopted as the background air quality in the assessment year. The hourly background concentrations for RSP were extracted from PATH. The PATH grids corresponding to the 500 m Study Area are (30, 28), (30, 29), (31, 28) and (31, 29).

3.7.14    PATH does not predict TSP and FSP. Since particulates of sizes larger than 10 µm generated from far-field dust sources should have been removed by deposition before reaching the ASRs, the background particulates would mainly be those less than or equal to 10 µm (i.e. PM₁₀/RSP). As a conservative approach, it was assumed that the hourly background concentration of TSP is equal to the hourly RSP concentrations calculated by PATH.

3.7.15    Also, the background daily and annual concentrations of FSP were predicted to be 75% of RSP and 71% of RSP, respectively, according to EPD’s “Guidelines on the Estimation of PM_2.5 for Air Quality Assessment in Hong Kong”.

Assessment Results

3.7.16    The predicted TSP, RSP and FSP concentrations at each ASR for unmitigated scenario including background contribution are summarized in Table 3-5, Table 3-6 and Table 3-7, respectively. Detailed results at different assessment levels are shown in Appendix 3.8. Without any mitigation measures, there would be potential exceedance of the hourly TSP criterion at all ASRs. The hourly and annual RSP would exceed the AQO criteria at most of the ASRs. All predicted concentrations of hourly FSP and annual FSP comply with the AQO.

3.7.17    The unmitigated cumulative contour maps of 1^st maximum 1-hour TSP, 10^th highest 24-hour RSP, annual average RSP, 10^th highest 24-hour FSP and annual average FSP at 1.5 m above ground are shown in Figure 3-5A to Figure 3-5E.

Table 3‑5    Unmitigated Cumulative Hourly TSP at ASRs (With Background)

ASR	Description	1st Max. 1-hr TSP
		Criteria=500 (μg/ m3)
A1	Shek Ku Lung Road Playground	1338.1
A2	Regal Hotel	797.6 - 1281.2
A3	South Mansion	1173.4 – 1266
A4	Jenford Building	1159.3 - 1260.4
A6	Parc 22	1041.2 - 1820.4
A7	Sky Tower	345.7 - 2311.3
A9	Mok Cheong Street Residential District	2209.3 - 2541.6
A16	Sung Wong Toi Playground	1590.5
A17	Fire Station	1495.1 - 1600
A13	Mok Cheong Street Residential District	1599 - 2522.4
A18	Lung To Street No.208	1283.3 - 1664.5
A19	HK society for Blind Hostel (facing Project Site)	2769.2 - 2774.1
A20	Grand Water Front (facing Project Site)	347.7 - 2040.4
A21	EMSD Headquarter	772.6 - 1512.1
PA1	KTD Site 1L	328.2 - 1807.4
PA2	KTD Site 1K	403.2 - 2219.9

* Bolded results represent exceedance of AQO

Table 3‑6    Unmitigated Cumulative Daily and Annual RSP at ASRs (With Background)

ASR	No. of Exceed. (24-hr RSP)	10th Max. 24-hr RSP	1st Max. 24-hr RSP	Annual RSP
	AQO=9	AQO=100 µg/m3	AQO=100µg/m3	AQO=50µg/m3
A1	5	95.1	124.1	47.9
A2	3 - 9	83.7 - 99.7	110.4 - 122.8	45.9 - 48.4
A3	5 - 6	92.2 - 95.6	116.1 - 119.9	47.7 - 48.2
A4	5 - 7	93 - 96.8	121 - 125.7	47.9 - 48.5
A6	11 - 26	105.4 - 114.3	122 - 147.8	51.3 - 54.1
A7	1 - 108	83.4 - 172.5	112.3 - 209.6	44.4 - 72.6
A9	126 - 128	212.9 - 223.2	268.4 - 280.7	80.3 - 82.7
A16	13	107.5	128.8	50.5
A17	17	109.8 - 113.1	146 - 151.6	53.2 - 53.9
A13	109 - 122	172.9 - 187	226.9 - 264.8	70.5 - 77
A18	88 - 100	150.7 - 169.9	180 - 198.5	65.7 - 69.9
A19	143	248.1 - 250.2	310.5 - 312.1	94.4 - 95.1
A20	2 - 73	86.1 - 177.3	112.3 - 226.6	43.2 - 61.8
A21	3 - 9	89.2 - 99.6	150.3 - 168.9	43.8 - 45.1
PA1	1 - 12	75.8 - 107.9	119 - 203.7	41.8 - 50.3
PA2	1 - 16	75.1 - 109.8	116.4 - 205.5	41.9 - 53.2

* Bolded results represent exceedance of AQO

Table 3‑7    Unmitigated Cumulative Daily and Annual FSP at ASRs (With Background)

ASR	No. of Exceed. (24-hr FSP)	10th Max. 24-hr FSP	1st Max. 24-hr FSP	Annual FSP
	AQO=9	AQO=75µg/m3	AQO=75µg/m3	AQO=35µg/m3
A1	1	56.16	81.81	29.15
A2	1	55.79 - 56.14	81.80	28.9 - 29.15
A3	1	55.79	81.80	29.11 - 29.13
A4	1	55.79	81.80	29.14 - 29.15
A6	1	55.85 - 55.98	81.8 - 81.83	29.44 - 29.72
A7	1	59.8 - 63.02	84.19 - 84.22	29.63 - 32.49
A9	2 - 3	67.1 - 67.78	84.31 - 84.34	33.26 - 33.53
A16	1	56.13	81.81	29.43
A17	1	56.17 - 56.19	81.86 - 81.88	29.65 - 29.7
A13	1	63.55 - 63.86	84.25 - 84.3	32.29 - 32.94
A18	1	63 - 63.15	84.22 - 84.24	31.8 - 32.21
A19	3 - 4	69.63 - 70.01	84.35 - 84.36	34.74 - 34.84
A20	1	59.39 - 64.39	84.19 - 84.65	29.51 - 31.39
A21	1	56.33 - 56.56	86.56 - 88.56	28.59 - 28.72
PA1	1	56.16 - 56.63	83.41 - 91.9	28.39 - 29.25
PA2	1	56.16 - 56.35	83.14 - 92.1	28.4 - 29.54

* Bolded results represent exceedance of AQO

Construction Dust Mitigation Measures

3.7.18    In order to reduce the dust emissions from the Project for compliance with the TSP and AQOs criteria at ASRs, the following specific mitigation measures are recommended.

3.7.19    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%. This dust suppression efficiency is derived based on the average haul road traffic, average evaporation rate and an assumed application intensity of 1.3 L/m² for the respective watering frequencies. Any potential dust impact and watering mitigation would be subject to the actual site conditions. The extent of watering may vary depending on actual site conditions but should be sufficient to maintain an equivalent intensity of not less than 1.3 L/m² to achieve the intended dust removal efficiency.

3.7.20    Dust control measures stipulated in the Air Pollution Control (Construction Dust) Regulation (Cap. 311R) and good site practice shall be adopted. The following dust suppression measures should be incorporated by the Contractor to control the dust nuisance throughout the construction phase:

·                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;

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

·                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;

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

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

·                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;

·                Haulage and delivery vehicles should be confined to designated roads;

·                Dusty materials on every vehicle's body and wheels should be removed in washing area before leaving the site;

·                Regular maintenance of all plant equipment;

·                Throttle down or switch off unused machines or machine in intermittent use;

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

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

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

Mitigated Construction Dust Level

3.7.23    With the mitigation measures as mentioned in Sections 3.7.18 to 3.7.22 above, construction dust levels for mitigated scenario are summarized in Table 3-8, Table 3-9 and Table 3-10. The detailed results are shown in Appendix 3.8. The mitigated cumulative results of hourly TSP, daily RSP, annual RSP, daily FSP and annual FSP comply with the respective criteria at all levels of the identified ASRs. 

3.7.24    The mitigated cumulative contour maps of 1^st maximum 1-hour TSP, 10^th highest 24-hour RSP, annual average RSP, 10^th highest 24-hour FSP and annual average FSP at 1.5 m above ground are shown in Figure 3-5F to Figure 3-5J. Although a few exceedance zones are predicted in the contour plots (mainly within the construction sites boundary), no existing or planned ASRs are located within the exceedance zones.

Table 3‑8    Mitigated Cumulative Hourly TSP at ASRs (With Background)

ASR	Description	1st Max. 1-hr TSP
		Criteria=500 (μg/ m3)
A1	Shek Ku Lung Road Playground	180.5
A2	Regal Hotel	172.5 - 214.5
A3	South Mansion	210.8 - 221.4
A4	Jenford Building	208 - 217.9
A6	Parc 22	170.9 - 249.6
A7	Sky Tower	153.4 - 303.5
A9	Mok Cheong Street Residential District	313.2 - 341.5
A16	Sung Wong Toi Park	222.5
A17	Fire Station	225.6 - 235.7
A13	Mok Cheong Street Residential District	257.9 - 336.8
A18	Lung To Street No.208	213 - 259.3
A19	HK society for Blind Hostel (facing Project Site)	359.1 - 360.6
A20	Grand Water Front (facing Project Site)	153.4 - 328.9
A21	EMSD Headquarter	179.2 - 359
PA1	KTD Site 1L	153.8 - 274.8
PA2	KTD Site 1K	155.9 - 302.1

* Bolded results represent exceedance of AQO

Table 3‑9    Mitigated Cumulative Daily and Annual RSP at ASRs (With Background)

ASR	No. of Exceed. (24-hr RSP)	10th Max. 24-hr RSP	1st Max. 24-hr RSP	Annual RSP
	AQO=9	AQO=100  (μg/ m3)	AQO=100 (μg/ m3)	AQO=50 (μg/ m3)
A1	1	74.9	109.2	40.8
A2	1	74.4 - 74.9	109.1 - 109.2	40.5 - 40.9
A3	1	74.4	109.1	40.8 - 40.9
A4	1	74.4	109.1	40.8 - 40.9
A6	1	74.8 - 74.9	109.2 - 109.4	41.1 - 41.5
A7	1	79.7 - 83.4	112.3 - 112.6	41.6 - 45
A9	1	87 - 88.1	113.5 - 113.7	46 - 46.5
A16	1	74.9	109.2	41.1
A17	1	75.2 - 75.4	109.7 - 109.8	41.5 - 41.7
A13	1	84.8 - 85.2	112.8 - 113.3	44.6 - 45.8
A18	1	84 - 84.1	112.6 - 112.8	44.1 - 44.8
A19	2	90.3 - 90.5	113.8	47.7 - 47.8
A20	1 - 2	79.7 - 86.8	112.3 - 116.7	41.5 - 44.3
A21	1	75.2 - 80	117.7 - 127.5	40.2 - 40.6
PA1	1	74.9 - 77.4	111 - 123.4	39.9 - 41.2
PA2	1	74.9 - 77.3	110.6 - 123.2	39.9 - 41.5

* Bolded results represent exceedance of AQO

Table 3‑10 Mitigated Cumulative Daily and Annual FSP at ASRs (With Background)

ASR	No. of Exceed. (24-hr FSP)	10th Max. 24-hr FSP	1st Max. 24-hr FSP	Annual FSP
	AQO=9	AQO=75 (μg/ m3)	AQO=75 (μg/ m3)	AQO=35 (μg/ m3)
A1	1	55.79	81.81	28.38
A2	1	55.79	81.80	28.35 - 28.39
A3	1	55.79	81.80	28.38
A4	1	55.79	81.80	28.38 - 28.39
A6	1	55.82 - 55.85	81.8 - 81.83	28.4 - 28.44
A7	1	59.35 - 59.8	84.19 - 84.22	29.34 - 29.69
A9	1	59.81	84.31 - 84.34	29.79 - 29.84
A16	1	55.84	81.81	28.41
A17	1	55.81 - 55.85	81.86 - 81.88	28.45 - 28.47
A13	1	59.75 - 59.8	84.25 - 84.3	29.65 - 29.76
A18	1	59.67 - 59.76	84.22 - 84.24	29.59 - 29.67
A19	1	59.83	84.35 - 84.36	29.96 - 29.98
A20	1	59.36 - 59.95	84.19 - 84.65	29.33 - 29.61
A21	1	56.16 - 56.35	83.27 - 84.33	28.23 - 28.27
PA1	1	56.16 - 56.26	82.59 - 83.9	28.2 - 28.33
PA2	1	56.16 - 56.2	82.55 - 83.89	28.2 - 28.36

* Bolded results represent exceedance of AQO

Residual Construction Dust Impact

3.7.25    With proper implementation of the recommended mitigation measures, all dust concentrations at ASRs are predicted to comply with the TSP criterion as well as the relevant AQOs for RSP and FSP.  Hence, no adverse residual impacts are anticipated during the construction phase.

3.8              Operational Phase Assessment

3.8.1        Potential air quality impacts arising from the operation of the Project are described in this section, including background air quality estimation, identification of air pollution sources and locations of representative ASRs, and the methodology adopted for the assessment. The assessment was conducted in accordance with Section 4 of Appendix A of the EIA Study Brief.

Assessment Methodology

3.8.2        The assessment of air quality impact in the operational phase follows the detailed technical requirements given in the EIA Study Brief. PATH (Pollutants in the Atmosphere and their Transport over Hong Kong) model was used to predict the future background concentrations of air pollutants. Air dispersion model CALINE4 (California Line Source Dispersion Model Version 4) was employed to predict the concentrations of air pollutants at the identified Air Sensitivity Receivers (ASR) due to tailpipe emissions from the existing and planned open road network within the Study Area; whereas ISCST3 (Industrial Source Complex Short-Term Model) was employed to predict the concentrations due to emissions from chimney, portal, ventilation building, cruise terminal and typhoon shelter.

3.8.3        The assessment focused on two main issues which are the degree of air quality impact caused by and on the Project. 

3.8.4        Air Quality Impact Caused by the Project: The Project itself is neither a polluting land use nor an air pollution source. The only potential air quality impact arising from the Project is caused by the traffic induced by the spectators/audiences travelling to and from the Project area during the course of major events at the Main Stadium of the MPSC such as sport events and concerts, as well as the traffic induced under the normal operation of the MPSC. The traffic induced by the audiences during major events shall only last for a short period of time (around an hour before and after each event). According to the Traffic Impact Assessment (TIA) report (2009), more than 80% of spectators/audiences would take MTR as their travelling means. Based on the local and overseas operation experiences of stadia of a similar scale, it is envisaged that major events at the Main Stadium of MPSC, especially a full-house event, would not be held frequently.  In addition, the parking area in the Project is limited (with capacity of below 1,000). Hence, no major vehicular traffic from the audiences is anticipated. It is estimated that the annual projection of induced traffic under normal operation and under full-event scenario to the total traffic in the Study Area for the worst assessment year (2023) are 2.26% and 2.49% respectively. The vehicular types with major contribution to the induced traffic are taxis and passenger cars which have relatively low air pollutant emissions than heavy good vehicles or buses. The estimated corresponding vehicular emissions, in terms of NOx, arising from the Project is about 1.36% of the total vehicular emission in the Study Area in 2023.  To assess the possible impact due to the traffic induced by the Project, the scenarios of “Without Project” and “With Project” were assessed for the worst assessment year. The detailed comparison of traffic flows and emissions of NOx are shown in Appendix 3.2.

3.8.5        Air Quality Impact on the Project: The users and operation staff of the facilities and venues in the Project may be affected to different extent by the ambient air quality in the area. The Project comprises a Main Stadium, a Public Sports Ground, an Indoor Sports Centre, and other ancillary/supporting facilities such as car parks, hotel, office area for sports-related organizations and commercial areas. Based on the local and overseas operation experience of stadia of a similar scale, it is anticipated that major events at the Main Stadium of MPSC would not be held frequently, and therefore users and operation staff will stay there intermittently. In view of the nature of the air sensitive uses in the Main Stadium, short-term rather than long-term air quality criteria are applicable. On the other hand, users and operation staff of the Public Sports Ground, Indoor Sports Centre, hotel, offices and commercial area may be affected in the short-term and long-term as they may stay there for a considerable length of the time throughout a year. As such, both short-term and long-term air quality impact assessments have been carried out for these receivers.

Background Air Quality

3.8.6        PATH is a macro-scale air quality model developed by EPD to predict future air quality over the whole Pearl River Delta region including Hong Kong. Currently, the nearest background air quality prediction from the worst assessment year (2023) is 2020. It was therefore adopted as the background air quality for the assessment year. The hourly background concentrations for NO₂, SO₂ and RSP were extracted from PATH. The PATH grids corresponding to the 500 m Study Area are (30, 28), (30, 29), (31, 28), and (31, 29). Since PATH does not predict FSP concentration, the background daily and annual concentrations of FSP was predicted as 75% of RSP and 71% of RSP respectively according to EPD’s “Guidelines on the Estimation of PM2.5 for Air Quality Assessment in Hong Kong”.

3.8.7        The air quality impact due to open road traffic within the Study Area was assessed using the near-field Gaussian Models, i.e. CALINE4 and ISCST3. As the default setting of PATH Model also includes open road emissions in its calculation, hence in order to avoid double accounting of emissions, the emissions of all open roads in the relevant PATH grids (correspond to the Study Area) have been removed from the emission inventory in the PATH grids.

3.8.8        Grid-dependent hourly meteorological data in Year 2010 were extracted from the PATH model. The PATH meteorological data, including temperature, wind speed, wind direction were adopted as input to CALINE4 and ISCST3. As no stability class information is available in PATH, PCRAMMET was used to generate such data. The mixing height was capped at 121m as per the real meteorological data.

Open Road Traffic

3.8.9        EMFAC-HK was employed to predict the hourly emission factors for 16 vehicle classes. In combination with the hourly vehicle kilometres travelled (VKT) of each road segment, the hourly fleet-averaged emission factors were obtained. The hourly fleet averaged emission factor together with the hourly traffic flow of each link were then utilized in CALINE4 to simulate the dispersion of vehicle exhaust pollutants induced by the Project and the surrounding open road network.  All major roads within 500m of the Study Area were included in the model.  The vehicular NOx, RSP and FSP emissions were calculated using the model. Details of the road network and the input parameters of EMFAC-HK are shown in Appendix 3.2. The calculated fleet averaged emission factor and traffic flow in each road link are given in Appendix 3.3.

3.8.10    The Ozone Limiting Method (OLM) has been adopted for the conversion of NOx to NO₂ based on the hourly O₃ concentrations predicted by PATH in the corresponding grid for all vehicle emissions. A tailpipe emission NO₂/NOx ratio of 7.5% according to the EPD’s “Guidelines on Choice of Models and Model Parameters” has also been assumed.  The NO₂/NOx conversion has been calculated as follows:

[NO₂]_pred = 0.075 × [NO_X]_pred + MIN {0.925 × [NO_X]_pred, or (46/48) × [O₃]_PATH}

 

3.8.11    As the model limits the road height to 10m, roads higher than 10m were set to 10m in model, as a conservative approach. For roads with barriers as a noise mitigation measure, the road type was set to “Fill” and the elevation was set at the top of the barrier. As noise barriers will also restrict the horizontal dispersion of the pollutant plume, the mixing width of this road was set to be the width of the road.

Portal and Ventilation Buildings

3.8.12    All portal and ventilation buildings within the Study Area have been identified based on a desktop study. These include CKR Tunnel east portal, CKR east ventilation building, Kai Tak Tunnel East and West portals, Kai Tak ventilation building and other portal emissions such as CKR Slip Road and Road D2 landscape deck. Figure 3-4 shows the locations of all portals and ventilation buildings.

3.8.13    According to the Permanent International Association of Road Congress Report (PIARC, 1991), the pollutants were assumed to eject from the portal as a portal jet such that 2/3 of the total emissions was dispersed within the first 50m of the portal and the other 1/3 of the total emissions within the second 50m.

3.8.14    With reference to the approved EIA study “Kai Tak Development” (KTD EIA), 50% of pollutant inside Kai Tak Tunnel was assumed to be emitted through the ventilation building and the remaining pollutant was assumed to be ejected through the tunnel portal.

3.8.15    Reference was also made to the approved CKR EIA report regarding the emission factors for CKR Eastbound Tunnel. The total length of the CKR tunnel is approximately 3.75km and the Central Ventilation Building (CVB) is at some 1.75km from the eastern portal. The current tunnel ventilation system is designed to extract a portion of the emissions (e.g. p%) from the first 2km of the east bound tunnel (EBT) to the CVB. The p% depends on the ratio of air flow rates between CVB and the Tunnel. The remaining portion of emission (e.g. 100-p%) will be mixed with that from the next 1.75km of EBT and 90% of these emissions will then be ventilated to Eastern Ventilation Building (EVB).  The remaining 10% will be emitted through the CKR eastern tunnel portal.

3.8.16    The 24-hour emission factor for each tunnel in 2023 has been adopted in compiling the emission inventory of portals and ventilation buildings. The calculation of emission factors for portals and ventilation buildings is given in Appendix 3.4. The 24-hour emission factors of different tunnel sections are given in Appendix 3.4.

Industrial Chimneys

3.8.17    Reference was made to the approved KTD EIA report for the emission data of industrial chimneys in the Study Area and this has been updated by site survey and made in line with the latest air pollution regulation. The detailed emission information of the industrial chimneys is presented in Appendix 3.5 and the locations are presented in Figure 3-4.

3.8.18    For industrial or marine emission sources, OLM has been adopted for the conversion of NOx to NO₂ based on the predicted O₃ concentrations from the corresponding PATH Grid. The NO₂/NOx conversion has been calculated as follows:

[NO₂]_pred = 0.1 × [NO_X]_pred + MIN {0.9 × [NO_X]_pred, or (46/48) × [O₃]_PATH}

Cruise Terminal

3.8.19    The ISCST3 dispersion model was employed to predict the air quality impact from emission sources other than road traffic emissions including the marine emissions from the Cruise Terminal, emissions from the typhoon shelter, and the industrial emissions from nearby chimneys within 1km.

3.8.20    According to the approved KTD EIA report, cruise ships will berth at the cruise terminals for one hour and then hotel for 23 hours. For safety of ship manoeuvring, only one ship berthing can take place at any one time. Only after one ship hotels, the second ship can berth at the remaining terminal.

3.8.21    In the KTD EIA report, the emission factors were based on the “Current Methodologies and Best Practices in Preparing Port Emission Inventories, Final Report, January 2006” prepared by ICF Consulting for USEPA. As the document has been updated in 2009, the emission factors of marine emissions have been reviewed and updated accordingly.

3.8.22    Furthermore, the new air pollution regulations “Air Pollution Control (Marine Light Diesel) Regulation” (Cap. 311Y) and “Air Pollution Control (Ocean Going Vessels) (Fuel at Berth) Regulation” (Cap. 311AA) became effective in 2014 and 2015 respectively and the sulphur contents of the vessel fuels are much lowered. Therefore the marine emissions have been re-calculated and are detailed in Appendix 3.6.

3.8.23    There are two modes of operation for the cruise ships: berthing mode and hotelling mode. The berthing mode includes 15 minutes for manoeuvring motions of the cruise vessels from the navigation channel to near the cruise terminal, 15 minutes for final manoeuvring around the berth and 30 minutes for hotelling. According to Appendix 3.6, emissions from the cruise ship during berthing are higher than emissions during hotelling. As the worst-case scenario, it has been assumed that the two cruise ships would operate in the berthing mode sequentially in the period coincidental with the peak hour of the traffic flow in the cumulative air quality assessment.

Typhoon Shelter

3.8.24    According to the approved KTD EIA report, there were around 60 barges berthing in To Kwa Wan Typhoon Shelter which has an area of about 233,200 m². The auxiliary engine power of each barge was assumed to be 82 kW emitting air pollutants at a height of 5m in this assessment as in the approved KTD EIA. As the requirements of sulphur contents for the current vessel fuel in Hong Kong have been recently tightened, the emission rates have been re-calculated and are detailed in Appendix 3.7. Location of To Kwa Wan Typhoon Shelter is shown in Figure 3-4.

Assessment Results

3.8.25    As mentioned in Section 3.6, Year 2023 would be the worst assessment year within 15 years after commencement of the Project. Vehicular emissions (include portal emissions), emissions from the Kai Tak Cruise Terminal and cruise ships, emissions from To Kwa Wan Typhoon Shelter, chimney emissions and emissions from ventilation buildings would all contribute to the cumulative air quality impact on the Project.

3.8.26    Cumulative air quality impact on each identified ASR in this Project was estimated by adding the modelling results due to background air quality by PATH model, open road vehicular emissions by CALINE4, as well as industrial emissions and marine emissions by ISCST3. The predicted cumulative concentrations of different pollutants at each ASR are compared against their respective AQOs.

Cumulative Impact for “Without Project” and “With Project” Scenarios in Year 2023

3.8.27    Cumulative air quality impacts on each identified ASR under the prevailing air quality conditions (i.e. “Without Project”) and during operation of this Project (i.e. “With Project”) were estimated by summing the modelling results from PATH, CALINE4 and ISCST3. Year 2023 was selected as the worst assessment year in 15 years upon commencement of operation of the Project. The purpose of presenting the “Without Project scenario was to provide a baseline level for comparison with the “With Project” scenario. As to be discussed below, exceedance of the AQO for annual NO₂ concentrations was found at some ASRs with the Project in operation. Hence, with the “Without Project” as a baseline, it is possible to attribute the causes for the exceedance of the AQO and to identify mitigation measures or remedial measures, if any, to render the residual air quality impact acceptable.

3.8.28    The applicable 1-hour, 24-hour and annual average cumulative concentrations of NO₂, RSP, FSP and SO₂ at each ASR at the worst predicted height above ground level are summarized in Tables 3-11 and 3-12 under the “Without Project” and “With Project” scenarios respectively. Details of the predicted results for all assessment levels of the ASRs are included in Appendix 3.9. Contour plots at the worst hit level of the above parameters are illustrated in Figures 3-6A to 3-6H for the “With Project” scenario.

3.8.29    The summary results indicated that the predicted concentrations of the key air pollutants (NO₂, RSP, FSP and SO₂) at Year 2023 are similar under both scenarios. With the exception of the annual NO₂, the predicted concentrations at all the representative ASRs of the key air pollutants (RSP, FSP, SO₂ and hourly NO₂) would comply with the respective AQOs. The contours maps indicated that apart from the 1-hour NO₂ concentration and annual NO₂ concentration plots, no AQO exceedance zone is observed for the other key air pollutants. Since the NO₂ exceedance zones for both 1-hour and annual NO₂ concentrations cover part of the Project site at 1.5mAG, contour plots at podium level (9.5mAG) of the Project are also provided in Figures 3-6I to 3-6J. The contours maps indicated that no ASR will be present in the 1-hour NO₂ exceedance zone. The AQO exceedance zones at the worst level (1.5 mAG) of the “With Project” scenario are described in Table 3-13.

Table 3‑11 Predicted Cumulative Air Pollutants Concentrations under “Without Project” Scenario at the Worst Level in Year 2023

ASR ID	NO2 Conc.		RSP Conc.		FSP Conc.		SO2 Conc.
	(µg/m3)		(µg/m3)		(µg/m3)		(µg/m3)
	19th Max. 1-hr	Annual	10th Daily	Annual	10th Daily	Annual	4th 10-minute	4th Daily
AQO	200	40	100	50	75	35	500	125
Prince Edward Road East  (Existing ASRs)
A1 – A4	169.2 –  180.7	31.8 –  61.2	73.2 –  73.9	39.3 –  40.7	55.0 –  55.5	28.0 –  29.2	150.0 – 229.7	22.4
Ma Tau Chung Road  (Existing ASRs)
A5, A5a, A6, A16	173.6 – 185.7	39.0 – 64.3	73.2 – 73.9	39.6 – 40.7	54.9 – 55.6	28.3 – 29.3	133.3 – 146.0	22.4
Ma Tau Kok Area/ Kowloon City Road (Kai Tak Tunnel West Portal) (Existing ASRs)
A7, A11, A12, A14, A15	184.7 – 192.1	34.3 – 61.3	77.9 – 78.4	40.9 – 42.6	58.6 – 58.9	29.1 – 30.7	131.4 – 299.6	23.1 – 23.2
To Kwa Wan Area  (Existing ASRs)
A8 – A10, A13	187.4 – 191.6	40.9 – 49.6	78.1 – 78.4	41.2 – 41.5	58.7 –  59.0	29.4 – 29.7	200.3 – 269.4	23.1
To Kwa Wan Area  (Planned ASRs)
PA12 – PA16	184.5 – 191.6	36.1 – 40.1	77.9 – 78.3	40.9 – 41.2	58.6 – 58.9	29.2 – 29.4	254.3 – 338.7	23.2 – 25.4
Olympic Avenue (Planned ASRs)
PA3 – PA11	167.9 – 186.4	27.4 –  33.7	73.2 –  74.0	39.1 – 39.4	54.9 –  55.7	27.8 –  28.0	151.0 – 294.2	22.4 – 24.7
Kai Tak Development Area (Planned ASRs)
PA17 – PA25	146.3 – 189.3	26.9 – 35.9	73.7 – 75.1	39.3 – 39.9	55.3 – 56.4	28.0 – 28.4	291.6 – 436.1	24.3 –  27.0
MPSC (Planned ASRs)
ASRs within MPSC	163.5 – 192.0	27.2 – 51.7	73.1 – 78.6	39.1 – 43.5	54.9 – 59.1	27.8 – 31.5	143.1 – 312.6	22.4 – 23.3

*              Bolded results represent exceedance of AQO

**           The predicted cumulative 4^th highest 10-minute SO₂ concentrations presented were calculated by multiplying the predicted cumulative maximum hourly SO₂ concentrations by the stability-dependent multiplicative factors. For conservativeness, the predicted cumulative 4^th highest 10-minute SO₂ concentration is the same as the predicted cumulative maximum 10-minute SO₂ concentration.

 

Table 3‑12 Predicted Cumulative Air Pollutants Concentrations under “With Project” Scenario at the Worst Level in Year 2023

ASR ID	NO2 Conc.		RSP Conc.		FSP Conc.		SO2 Conc.
	(µg/m3)		(µg/m3)		(µg/m3)		(µg/m3)
	19th Max. 1-hr	Annual	10th Daily	Annual	10th Daily	Annual	4th 10-minute	4th Daily
AQO	200	40	100	50	75	35	500	125
Prince Edward Road East  (Existing ASRs)
A1 – A4	169.2 – 180.7	31.8 – 61.2	73.2 – 73.9	39.3 – 40.7	55.0 – 55.6	28.0 – 29.2	150.0 – 229.7	22.4
Ma Tau Chung Road  (Existing ASRs)
A5, A5a, A6, A16	173.7 – 185.9	39.4 – 64.4	73.2 – 74.0	39.6 – 40.7	54.9 – 55.7	28.3 – 29.3	133.3 – 146.0	22.4
Ma Tau Kok Area/ Kowloon City Road (Kai Tak Tunnel West Portal) (Existing ASRs)
A7, A11, A12, A14, A15	184.7 – 192.2	34.4 – 61.4	77.9 – 78.4	40.9 – 42.7	58.6 – 58.9	29.1 – 30.7	131.4 – 299.6	23.1 – 23.2
To Kwa Wan Area  (Existing ASRs)
A8 – A10, A13	187.7 – 191.7	41.2 – 50.2	78.1 – 78.4	41.2 – 41.6	58.7 – 59.0	29.4 – 29.7	200.3 – 269.4	23.1
To Kwa Wan Area  (Planned ASRs)
PA12 – PA16	184.7 – 191.7	36.2 – 40.2	77.9 – 78.4	41.0 – 41.2	58.6 – 58.9	29.2 – 29.4	254.3 – 338.7	23.2 – 25.4
Olympic Avenue (Planned ASRs)
PA3 – PA11	168.0 – 186.4	27.4 – 33.8	73.2 – 74.0	39.2 – 39.4	54.9 – 55.7	27.8 – 28.0	151.0 – 294.2	22.4 – 24.7
Kai Tak Development Area (Planned ASRs)
PA17 – PA25	146.3 – 189.5	27.0 – 35.9	73.7 – 75.1	39.3 – 39.9	55.3 – 56.4	28.0 – 28.4	291.6 – 436.1	24.3 – 27.0
MPSC (Planned ASRs)
ASRs within MPSC	163.5 – 192.9	27.3 – 51.9	73.1 – 78.7	39.1 – 43.5	54.9 – 59.1	27.8 – 31.6	143.1 – 312.6	22.4 – 23.3

*              Bolded results represent exceedance of AQO

**           The predicted cumulative 4^th highest 10-minute SO₂ concentrations presented were multiplying the predicted cumulative maximum hourly SO₂ concentrations by the stability-dependent multiplicative factors. For conservativeness, the predicted cumulative 4^th highest 10-minute SO₂ concentration is the same as the predicted cumulative maximum 10-minute SO₂ concentration.

 

Table 3‑13 Details of Exceedance Zones at the Worst Level in the Worst Assessment Year (2023)

Exceedance Zone	Details
19th max. 1-hour NO2 at 1.5mAG
Near the Ventilation Building and Tunnel Portal of CKR	Part of the exceedance zone covers the carpark in the eastern part of the Main Stadium at ground level. The rest of the exceedance zone covers the open area and roads. So there is no ASR within the exceedance zone.
Annual NO2 at 1.5mAG
Prince Edward Road East, Ma Tau Chung Road, Ma Tau Kok Area/ Kowloon City Road (Kai Tak Tunnel West Portal), and To Kwa Wan Area	The exceedance zone covers roads, schools, shops, church, playground and performing arts centre. For planned land use, some CDA zoned sites and R(A) zoned sites are wholly or partly fall within the exceedance zone. Moreover, the western corner of the hotel within the Project site is also within the exceedance zone. Notwithstanding this, ASR is unlikely located at G/F of the future development in the CDA or R(A) zoned sites. The fresh air intake of the hotel block in MPSC would be located at 5mAG or above.
Near CKR Tunnel Portal, Landscape Deck Portal and Ventilation Building, and MPSC	The exceedance zone covers the Main Stadium, car parking area, government facility buildings and roads. For planned land use, some open space and commercial zoned sites are wholly or partly fall within the exceedance zone. Only the Main Stadium is classified as an ASR. However, as stated in Section 3.8.5, audience and operation staff of the Main Stadium will only stay during the course of an event. The building within the commercial use zone is likely to be installed with central air-conditioning system and the air intake in the future is unlikely at ground level. Hence, the long-term air quality impact does not apply to users/staff of the Main Stadium and no adverse air quality impact is expected.

 

3.8.30    ASRs experiencing exceedance in AQOs in both “Without Project” and “With Project” scenarios are located near road networks, including Prince Edward Road East, Ma Tau Chung Road, Kowloon City Road, Sung Wong Toi Road, To Kwa Wan Road, Mok Cheong Street and the landscape desk opening of the future Central Kowloon Route.

3.8.31    In order to identify the major NO₂ contributor, Appendix 3.9 tabulates the contributions from different emission sources to annual average NO₂ at ASRs where exceedance occurs, including the background air pollution, traffic emissions (open road vehicular emission and emissions from portal & ventilation building), as well as chimney emissions (industrial chimneys, To Kwa Wan Typhoon Shelter and Cruise Terminal).

3.8.32    It is noted that annual average NO₂ concentrations at most of the identified ASRs in this Project are dominated by the background air pollution level (predicted using PATH) in both “With Project” and “Without Project” scenarios. Contributions from chimneys and marine emissions are relatively low in this region.

Comparison of Annual Average NO₂ Concentrations between “With Project” and “Without Project” Scenarios in Year 2023

3.8.33    In order to investigate whether operation of the Project will cause any adverse impact on the prevailing air quality conditions, the annual average NO₂ concentrations  under the “Without Project” and “With Project” scenarios for identified ASRs with annual NO₂ exceedance have been compared in Table 3-14.  Detailed comparison are shown in Appendix 3.9.

Table 3‑14 Comparison of Annual NO₂ Concentrations between “With Project” and “Without Project” (Year 2023) for ASRs with Annual NO₂ Exceedance

ASR ID	m above ground	Without Project	With Project and 60 Days Full Event
		Overall     (µg/m3)	Overall (µg/m3)	Impact From Project
				(µg/m3) [i]	%[ii]
AQO = 40 µg/m3
Prince Edward Road East  (Existing ASRs)
A1, A3, A4	1.5	52.8 – 61.2	52.8 – 61.2	0.03 – 0.05	0.1%
	5.0	49.7 – 54.0	49.7 – 54.1	0.06	0.1% – 0.2%
	10.0	42.4 – 43.1	42.4 – 43.2	0.06 – 0.08	0.2%
Ma Tau Chung Road  (Existing ASRs)
A5, A5a, A16	1.5	40.0 – 64.3	40.3 – 64.4	0.16 – 0.22	0.4% – 0.5%
	5.0	45.8 – 46.6	46.0 – 46.8	0.19	0.5%
Ma Tau Kok Area/ Kowloon City Road (Kai Tak Tunnel West Portal)  (Existing ASRs)
A11, A12, A14, A15	1.5	42.2 – 61.3	42.4 – 61.4	0.15 – 0.26	0.4% – 0.6%
	5.0	38.5 – 55.9	38.7 – 56.0	0.11 – 0.19	0.3% – 0.5%
	10.0	36.9 – 46.9	37.1 – 47.0	0.11 – 0.15	0.3% – 0.4%
To Kwa Wan Area  (Existing ASRs)
A8 – A10, A13	1.5	41.7 – 49.6	41.8 – 50.2	0.16 – 0.56	0.4% – 1.4%
	5.0	38.7 – 41.5	38.8 – 41.9	0.13 – 0.34	0.3% – 0.9%
To Kwa Wan Area  (Planned ASRs)
PA15[iii]	1.5	40.1	40.2	0.15	0.4%

i.                          As stated in Section 3.8.10, conversion from NOx to NO₂ is based on OLM method. The conversion of NOx to NO₂ is a result of a series of complex photochemical reactions. The NO₂ is based on 7.5% NOx and the background Ozone concentration.

ii.                        Impact from Project comparing to AQO in percentage.

iii.                       PA15 is located in KTD Site 5A4 which is zoned as CDA. The fresh air intake of the future development is recommended to be at least 5m above ground.

*                 Bolded results represent exceedance of AQO.

**              Refer to Table 3-2, the air intake/sensitive use for A2 and A7 are above podium level (>20mAG) and thus they are not included in the above table even they are located within the exceeding zone of NO₂ shown in Figures 3-6B and 3-6J.

***            Refer to Section 3.8.5, audience and operation staff of the Main Stadium will only stay during the course of an event and hence the long-term air quality impact does not apply to users/staff of the Main Stadium. Therefore, the ASRs for the Main Stadium are not included in the above table even they are located within the exceeding zone of annual NO₂ shown in Figures 3-6B and 3-6J.

3.8.34    As shown in Table 3-14, the differences of predicted annual NO₂ between the “Without Project” and “With Project” scenarios range from 0.03 µg/m³ to 0.56 µg/m³. According to Appendix 3.9, apart from ASRs A9 and A13 at 1.5m, the contribution due to the Project at all the ASRs with exceedance of annual NO₂ is less than 1% of the AQO criterion. As the ground floor of A9 and A13 are shops, it is expected that the staff is working at the shops for at most 12 hours a day and 6 days a week instead of continuously for 24 hours a day and 365 days a year. Hence, the actual exposure to the NO₂ shall be less than those predicted.

Study of Annual NO₂ Concentration for “Without Project” and “With Project” Scenarios in Selected Assessment Years from 2023 to 2036

3.8.35    In the previous section, air quality impact at the worst-assessment Year 2023 associated with this Project has been studied, and exceedance of annual NO₂ has been identified at a number of ASRs for both “Without Project” and “With Project” scenarios. In order to investigate the changes in the prevailing air quality conditions and the cumulative annual NO₂ results in the long term across the 15-year assessment year, a further study for Year 2026 and Year 2036 has been conducted for both the “With Project” and “Without Project” scenarios.

3.8.36    The annual average NO₂ concentrations under the “Without Project” and “With Project” scenarios for Year 2036 for identified ASRs with annual NO₂ exceedance in 2023 have been compared in Table 3-15.  Despite the fact that exceedance of annual NO₂ concentration has been identified in both Year 2023 and Year 2036, the highest annual NO₂ concentration has been reduced from 64.4mg/m³ in Year 2023 to 46.6mg/m³ in Year 2036, (about 28% reduction as shown in Table 3-14 and Table 3-15).  In addition, the number of ASRs exceeding the AQO for annual NO₂ has been largely reduced from 15 to 5 (about 67% reduction) from Year 2023 to Year 2036 as shown in Table 3-16. Therefore, the overall air quality is expected to be gradually improving from Year 2023 to Year 2036.

3.8.37    The annual average NO₂ level in Year 2036 is expected to exceed the AQO at only five representative ASRs in Year 2036 (i.e. A1, A4, A5a and A9 at G/F and A15 at G/F & 1/F). A1 represents Shek Ku Lung Road Playground immediately north of Prince Edward Road East and the southern part of the playground would fall within the AQO annual NO₂ exceedance zone. A4, A5a, and A9 where exceedance was predicted represent shops at ground level on Prince Edward Road East, Ma Tau Chung Road, and Mok Cheong Street respectively. A15 where exceedance is predicted represents shops at ground level and residences on 1^st floor level of the buildings in the vicinity of Po Sum Mansion on Kowloon City Road. Moreover, the exposure to NO₂ for the users at playground (A1) and the staff of the shops (A4, A5a and A9) should be limited as they will not stay continuously for 24 hours a day and 365 days a year.

3.8.38    It should be noted that the exceedance of annual NO₂ at these ASRs is mainly caused by background air quality which is dominated by vehicle emissions from existing roads, whilst the NO₂ generated off-site from the induced traffic of the Project contributes less than 1% to the AQO criterion at all the ASRs in Year 2036, and this contribution does not cause any additional increase in the number of ASRs exceeding the AQO for annual NO₂ as shown in Table 3-16. 

3.8.39    Figures 3-6K to 3-6P show contour plots for comparing the annual average NO₂ concentration under “Without Project” and “With Project” scenarios at 1.5m and 5.0m above ground in Years 2023, 2026 and 2036. As seen from the above mentioned contour plots, increases in the exceedance zone due to the contribution from the Project in the assessment years are unnoticeable. Moreover, the exceedance zones are localized on some road sections and the covered areas are significantly reduced in Year 2036. Table 3-17 describes the details of the ASRs within the annual NO₂ exceedance zones in Year 2036.

Table 3‑15 Comparison of Annual NO₂ Concentrations between “With Project” and “Without Project” (Year 2036)

ASR ID	m above ground	Without Project	With Project and 60 Days Full Event
		Overall     (µg/m3)	Overall (µg/m3)	Impact From Project
				(µg/m3) [i]	%[ii]
AQO = 40 µg/m3
Prince Edward Road East  (Existing ASRs)
A1, A3, A4	1.5	38.9 – 45.3	38.9 – 45.3	0.05 – 0.06	0.1%
	5.0	36.9 – 39.6	36.9 – 39.7	0.05 – 0.07	0.1% – 0.2%
	10.0	32.9 – 33.3	32.9 – 33.4	0.05 – 0.06	0.1% – 0.2%
Ma Tau Chung Road  (Existing ASRs)
A5, A5a, A16	1.5	32.4 – 46.4	32.6 – 46.6	0.14 – 0.19	0.4% – 0.5%
	5.0	34.2 – 34.6	34.3 – 34.8	0.12 – 0.14	0.3% – 0.4%
Ma Tau Kok Area/ Kowloon City Road (Kai Tak Tunnel West Portal)  (Existing ASRs)
A11, A12, A14, A15	1.5	35.4 – 51.7	35.5 – 51.8	0.10 – 0.17	0.3% – 0.4%
	5.0	33.9 – 46.9	34.0 – 47.0	0.09 – 0.13	0.2% – 0.3%
	10.0	33.1 – 39.5	33.2 – 39.6	0.09 – 0.10	0.2% – 0.3%
To Kwa Wan Area  (Existing ASRs)
A8 – A10, A13	1.5	36.3 – 41.3	36.5 – 41.6	0.12 – 0.36	0.3% – 0.9%
	5.0	34.8 – 36.9	34.9 – 37.1	0.09 – 0.22	0.2% – 0.6%
To Kwa Wan Area  (Planned ASRs)
PA15	1.5	36.1	36.2	0.11	0.3%

i.                     As stated in Section 3.8.10, conversion from NOx to NO₂ is based on OLM method. The conversion of NOx to NO₂ is a result of a series of complex photochemical reactions. The NO₂ is based on 7.5% NOx and the background Ozone concentration.

ii.                   Impact from Project comparing to AQO in percentage.

iii.                  PA15 is located in KTD Site 5A4 which is zoned as CDA. The fresh air intake of the future development is recommended to be at least 5m above ground.

*             Bolded results represent exceedance of AQO.

 

Table 3-16 Number of Representative ASRs exceeding AQO Criteria for Annual NO₂

Group of ASR	Without Project		With Project and 60 Days Full Event
	Year 2023	Year 2036	Year 2023	Year 2036
Prince Edward Road East	3	2	3	2
Ma Tau Chung Road	3	1	3	1
Ma Tau Kok Area / Kowloon City Road (Kai Tak Tunnel West Portal)	4	1	4	1
To Kwa Wan Area (Existing ASR)	4	1	4	1
To Kwa Wan Area (Proposed ASR)	1	0	1	0

[i]                  Detailed results are shown in Appendix 3.9.

 

 Table 3‑17 Details of Exceedance Zones in Year 2036

Exceedance Zone	Details
Annual NO2 at 1.5mAG
Prince Edward Road East  (Existing ASRs)	The exceedance zone covers the southern portion of a playground, part of Princess Edward Road East and some shops at the northwest side of the road. The staff in the shops would at most work for 12 hours a day. The exposures of the users of playground and staff in shops are expected to be limited instead of continuous.
Ma Tau Chung Road	The exceedance zone covers part of Ma Tau Chung Road, some shops along the road and part of the landscaped area of a playground. As mentioned above, the limited exposures of the users of playground and staff in the shops are expected.
Ma Tau Kok Area/ Kowloon City Road (Kai Tak Tunnel West Portal)	The exceedance zone covers shops near Kowloon City Road, Ma Tau Kok Road and Pau Chung Street. The exceedance zone also covers part of a performing arts centre. As mentioned above, the limited exposures of the staff in the shops are expected.
To Kwa Wan Area	The exceedance zone covers some shops along Mok Cheong Street. As mentioned above, the limited exposure of the staff in the shops is expected.
Near CKR Portal Tunnel Portal, Landscape Deck Portal and Ventilation Building, and MPSC	The exceedance zone covers the southeastern portion of Main Stadium, car parking area, and roads. Only the Main Stadium is classified as ASR. However, as stated in Section 3.8.5, the audience and operation staff of the Main Stadium will only stay in during course of an event. Hence, the long-term air quality impact does not apply to users/staff of the Main Stadium and no adverse air quality impact is expected.
Annual NO2 at 5.0mAG
Ma Tau Kok Area/ Kowloon City Road (Kai Tak Tunnel West Portal)	The exceedance zone covers residential buildings near Kowloon City Road, Pau Chung Street, San Shan Road and Ma Tau Kok Road. The exceedance zone also covers a home for the aged and two kindergartens in Pau Chung Street.
Near CKR Portal Tunnel portal, Landscape Deck Portal and Ventilation Building, and MPSC	The exceedance zone covers the southeastern portion of Main Stadium, car parking area, and roads. Only the Main Stadium is classified as ASR. However, audience and operation staff of the Main Stadium will only stay during the course of an event. Hence, the long-term air quality impact does not apply to users/staff of the Main Stadium and no adverse air quality impact is expected.

 

Mitigation Measures

3.8.40    As indicated in Table 3-14 and Table 3-15, the Project would only contribute a maximum of 1.4% of the AQO to the identified ASRs where AQO exceedances for the annual average NO₂ in Year 2023 occur. It will further be reduced to a maximum of 0.9% of the AQO in Year 2036.  Various mitigation measures targeting on mitigating NO₂ levels have been explored. Details of the recommended mitigation measures are set out below.

Traffic Management

3.8.41    Traffic management is one of the measures explored in this Study. Most vehicles visiting MPSC would travel from Tsim Sha Tsui and Hung Hom (including vehicles from Cross Harbour Tunnel) via Chatham Road North, East Kowloon Corridor, Kowloon City Road reaching To Kwa Wan to Road D2 (see Table 3 and Annex I in Appendix 3.2). One of the options is to direct the traffic especially those heavy vehicles carrying equipment to enter the MPSC via Road D2 from Kai Tak East instead of from To Kwa Wan in order to reduce the traffic loadings on Mok Cheong Street, To Kwa Wan Road, Ma Tau Kok Road, Kowloon City Road and Sung Wong Toi Road. This may be done by restricting the entry of the vehicular traffic from east bound of Road D2 to turn right or left into the sports complex.

3.8.42    However, to bypass To Kwa Wan, vehicles would have to detour via Prince Edward Road East through Mongkok, or Central Kowloon Route through west Kowloon. Drivers are expected to use Road D2 via To Kwa Wan and take advantage of the roundabout on the east of the Project site to enter MPSC from the west bound of Road D2. This would further increase the loadings of the already heavily congested roads and require longer travelling distance to the MPSC. Therefore, restricting the entry of vehicular traffic from the east bound of Road D2 is not practical. In addition, the total emissions from these vehicles would be higher due to the extra mileage of travel and would have created unnecessary traffic on Roads D2 and D3.

Restriction on loading and unloading time

3.8.43    While it is not viable to restrict the heavy vehicles to enter the MPSC site via Road D2, it is possible to restrict the loading and unloading of these heavy vehicles to off-peak hours. This measure would reduce traffic loading on the roads in nearby area during the peak hours and in turn would reduce vehicle emissions.

Reduction of Emissions at Source

3.8.44    Another measure considered is the reduction of emissions at source. This can be done by requiring vehicles under the management control of the future MPSC operator to use electric vehicles (EV) such as electric saloon cars/coaches during the operation of the MPSC.   In order to encourage the use of EV, it is recommended further that EV charging points and EV charging enabling facilities on par with Government’s best practice guide should be provided at the carparks within the MPSC site. A review on the provision of EV charging facilities will be reviewed by the future operator. Subject to the outcomes of the review to be carried out by the future operator, the provision of the EV charging facilities may be further enhanced to meet the prevailing demand. The operator shall also give priority to EV using the car parking spaces as far as practicable. For example, the operator may develop a booking system for the parking spaces for private cars.  EV owners can have the privilege to book car parking spaces earlier than other non-EV owners.

Reduction of Car Parking Spaces

3.8.45    Car parking spaces will be provided for the sport venues, retail area, office and hotel to cater for their operation requirements.  The number of car parking spaces for the venues and facilities has made reference to similar overseas stadiums and follow the Hong Kong Planning Standard and Guidelines (HKPSG) as appropriate.  The lower limits of parking provisions for retail area, office and hotel in the HKPSG have been adopted as far as practicable to discourage use of cars.  Possible reduction in the car parking spaces has been considered (reduced from 1,200 to below 1,000) to account for the different peak utilization periods of the venues and facilities. The Transport Department has also advised that any downward adjustment of the number of parking spaces is not recommended from the traffic point of view and shall be supported by traffic figures. In any case, car parking spaces for coaches, goods vehicles and working/services/emergency vehicles would be less than 300.

Recommended Mitigation Measures

3.8.46    All practical measures to limit vehicle emissions from MPSC will be implemented by the operator include: -

·         Provision of electric vehicle (EV) charging facilities in at least one-third of the car parking spaces for private cars;

·         Provision of EV charging enabling facilities in all car parking spaces provided for private cars;

·         Giving priority to EV using the car parking spaces as far as practicable;

·         If the operator provides transport services for the staff and/or guests, electric saloon cars, coaches, etc. should be used under normal operation; and

·         Entry of heavy goods vehicles to MPSC should avoid peak hours, weekdays from 7 am to 10 am and from 4 pm to 7 pm, except for major events (i.e. with more than 20,000 persons).

3.8.47    Regarding the possible air quality impact on the Project, the fresh air intake of the hotel block in MPSC shall be located at least 5mAG.

Evaluation of Residual Impact

3.8.48    As presented in the preceding sections, all the air quality criteria as stipulated in the Air Quality Objectives and in the EIAO-TM are met, with the exception of the annual NO₂. 

3.8.49    The recommended mitigation measures in Section 3.8.46 would help reduce the annual NO₂ emissions but their benefits are not easily quantifiable for the purpose of evaluating the residual impacts. As such, the residual impacts are evaluated based upon the assessment results in Table 3-14 to Table 3-15 which would potentially be further reduced when the future operator puts in place the mitigation measures as far as practicable during the project implementation stage. On this basis, exceedance of AQO for annual NO₂ is predicted in localised areas as shown in Figures 3-6K to 3-6L. Notwithstanding this, based on Table 3-14 and Table 3-15, the maximum project contribution to the identified exceedances of the annual average NO₂ in 2023 is only 1.4% of the AQO, and it will be reduced to a maximum of 0.9% of the AQO in Year 2036.

3.8.50    The residual air quality impacts are evaluated in the following sections in accordance with Section 4.4.3 of EIAO-TM with a view to examining whether the residual air quality impact arising from the Project will cause long term serious environmental implications.

Air Quality Impact due to the Project

3.8.51    The Project itself is not an air pollution source. Referring to Appendix 3.9, the AQO exceedance of the annual NO₂ under the “With Project” scenario is dominated by the background air pollution level. According to the contour plots in Figure 3-6K to Figure 3-6P, the annual NO₂ concentration exceedance zones predicted in 2023 are not widespread but localised areas which will be largely reduced in Year 2036. In other words, the geographical extent of the impacts caused by the induced traffic from the Project is not long range but occurs in the road network in the vicinity of the Project.  Moreover, the Project will not cause noticeable increases in the exceedance zones in both assessment years as seen from the contour plots under the “Without Project” and “With Project” scenarios.

3.8.52    As shown in Table 3-14 and Table 3-15, the highest predicted annual NO₂ concentration at the identified ASRs (representing shops at Kam Wah Building near Ma Tau Chung Road) is 64.4 µg/m³ in Year 2023, which will be reduced to 46.6 µg/m³ in Year 2036. The exceedances are largely due to the background air pollution levels, and the contribution from the Project is only 0.19 µg/m³ (i.e. 0.5% of the AQO limit) at the identified ASR in Year 2036. As mentioned in Section 3.8.34, the staff would at most be working for 12 hours a day and 6 days a week, and therefore they would have limited exposure to this level of NO₂. On this basis, the magnitude of contribution to the cumulative annual NO₂ concentration due to the Project when considered in conjunction with the impacts from prevailing background and other potential projects in Year 2036 is considered minimal, and therefore the potential associated health effect from the minimal additional air pollutants caused by the Project itself is considered negligible and unlikely to be a key concern.

Continuous Improvement of Air Quality Conditions

3.8.53    With the implementation of the air quality improvement programmes currently being undertaken by the Government, such as “A Clean Air Plan for Hong Kong” which aims to tackle roadside air pollution and to reduce marine emissions, continuous air quality improvement in the territory is expected. This is supported by the assessment results in Table 3-15. Based on these assessment results, the predicted magnitude of annual NO₂ concentrations at all the representative ASRs will be reduced from the worst assessment year of Year 2023 to Year 2036 (15 years after the Project commencement). Furthermore, the number of ASRs being exposed to NO₂ levels exceeding the annual criteria will be largely reduced from 15 to 5 from Year 2023 to Year 2036. As demonstrated by the improving trend of air quality conditions, the air quality impact arising from the Project will be off-set in the longer term by the Government’s air quality improvement programme. The likelihood of future adverse environmental impacts caused by the operation of the Project itself is not high.

3.8.54    As shown in Figures 3-6K to 3-6P, the exceedance zones for annual NO₂ in Year 2023 and Year 2036 are localised. The affected areas and hence the likely size of community affected are not widespread. As seen from the mentioned above contour plots, increases in the exceedance zones due to the contribution from the Project in both assessment years are unnoticeable. Based on the assessment results, similar population would be affected without the Project. The affected communities mainly consist of the staff in the shops at ground floor, who have limited exposure to the NO₂ impact. As air quality improves over time, the small affected population in Year 2023 will be further reduced to a limited size in Year 2036. Details of the estimated likely size of the affected population are shown in Appendix 3.10.

Others Considerations

3.8.55    The non-compliance of annual NO₂ AQO criterion occurred only in some localised areas which are considered not of regional concern. In addition, the residual impact would not cause any ecological or cultural heritage concerns.

3.8.56    Pollutant concentrations predicted by PATH in Year 2020 have been adopted for the background air quality for the assessment years from Year 2023 (the worst assessment year) to Year 2036 (15 years after the commencement of the Project). In consideration of air quality improvement schemes implemented by the Government that would gradually take effect following Year 2020, the use of the Year 2020 PATH background in predicting pollutant concentration in Years 2023 to Year 2036 is considered conservative. As such, both the likelihood and degree of uncertainty of adverse environmental impacts are minimized.

3.8.57    Based on the analysis in Sections 3.8.48 to 3.8.56 above, it is clearly demonstrated that the residual impact of annual NO₂ is predominantly caused by existing background concentrations unrelated to this Project, and the impacts caused by this Project itself are minimal.  It is thus concluded that the residual air quality impact caused by the Project will not cause long term serious environmental implications.

3.9              Conclusion

3.9.1        This Chapter presents an air quality impact assessment for the construction and operational phases of the Project.

3.9.2        Potential air quality impacts from the construction works of the Project would mainly be related to construction dust from site clearance, excavation, foundation and site formation works. Construction dust impact arising from this Project with consideration of concurrent projects has been assessed for both the unmitigated and mitigated scenarios. With proper implementation of the recommended mitigation measures, it has been assessed that all dust concentrations at ASRs are predicted to comply with the TSP criterion as well as the relevant AQOs for RSP and FSP. Hence, there are no adverse residual air quality impacts anticipated during the construction phase.

3.9.3        The air emission sources during operational phase include open road traffic emissions, marine emissions from the Kai Tak Cruise Terminal, emissions from To Kwa Wan Typhoon Shelter, industrial emissions from nearby chimneys within 1km of the Project site, and the background pollutant concentration predicted by PATH. Based on the sensitivity test result, Year 2023 is the worst assessment year within the next 15 years upon commissioning of the Project in Year 2021. CALINE4 has been used to predict the pollution concentrations from traffic emissions while ISCST3 has been used to predict the concentrations from other sources.

3.9.4        The only air emission source due to the Project is the induced traffic along the traffic routes leading to or from the future MPSC, while the Project does not produce air emissions of significant amounts. Cumulative impact for both “Without project” and “With project” scenarios have been assessed. Based on the modelling results, it is predicted that the concentrations in respect of 10-min. SO₂, hourly SO₂, daily RSP, annual RSP, daily FSP, annual FSP, and hourly NO₂ at all the identified ASRs would be in compliance with the AQOs for both scenarios.

3.9.5        Although part of the Main Stadium falls within the annual NO₂ exceedance zone, spectators/audience/staff of the Main Stadium will only stay during the course of events, and hence, the long-term air quality impact does not apply to users/staff of the Main Stadium. As the hotel shall be serviced by a central air conditioning system, no adverse impact is anticipated so long as the fresh-air intake points of the building are located outside the annual NO₂ exceedance zone (at least 5m above ground).

3.9.6        ASRs located along the roads with traffic induced by the operation of the Project have been identified for evaluating the potential air quality impact due to the operation of the Project. Exceedances of annual average NO₂ were found only at 1.5m, 5m and 10m levels of some identified ASRs. Assessment results indicated that exceedances at most of the ASRs are largely due to the background air pollutant levels, and the same ASRs would have annual average NO₂ exceeding the AQOs even without the Project.

3.9.7        With the implementation of the air quality improvement programmes currently being undertaken by the Government, such as “A Clean Air Plan for Hong Kong” which aims to tackle roadside air pollution and to reduce marine emissions, continuous air quality improvement in the territory is expected.  Based on these assessment results, the pollutant concentrations would be largely reduced and the number of ASRs complying with the AQOs would be increased from Years 2023 to 2036. Furthermore, the number of ASRs being exposed to NO₂ levels exceeding the annual criterion will be largely reduced from 15 to 5 (i.e. A1, A4, A5a and A9 at G/F and A15 at G/F & 1/F) from Year 2023 to Year 2036. A1 represents the playground to the north of Prince Edward Road East. A4, A5a, and A9 where exceedance was predicted represent shops at ground level on Prince Edward Road East, Ma Tau Chung Road, and Mok Cheong Street respectively. A15 where exceedance is predicted represents shops at ground level and residences on 1^st floor level of the buildings in the vicinity of Po Sum Mansion on Kowloon City Road. The exceedance for annual NO₂ at these ASRs is mainly due to the background air pollution levels, whilst the highest NO₂ generated off-site from the induced traffic of the Project contributes 0.9% to the AQO criterion in Year 2036, and this contribution does not cause any additional increase in the number of ASRs exceeding the AQO for annual NO₂.

3.9.8        The non-compliance of annual NO₂ AQO criterion occurs only in some localised areas which are considered not of regional concern. In addition, the residual impact would not cause any ecological or cultural heritage concerns.

3.9.9        Pollutant concentrations predicted by PATH in Year 2020 have been adopted for the background air quality for the assessment years from Year 2023 (the worst assessment year) to Year 2036 (15 years after the commencement of the Project). In consideration of air quality improvement schemes implemented by the Government that would gradually take effect following Year 2020, the use of Year 2020 PATH background in predicting pollutant concentration in Years 2023 to 2036 is considered conservative. As such, both the likelihood and degree of uncertainty of adverse environmental impacts are minimized.

3.9.10    Various options of mitigation measures have been explored. Practical measures to be implemented include: (a) provision of electric vehicle (EV) charging facilities in at least one-third of the car parking spaces for private cars, (b) provision of EV charging enabling facilities in all car parking spaces for private cars, (c) giving priority to EV using the car parking spaces as far as practicable, (d) use of electric saloon cars and coaches in the transport services for staff and/or hotel guests under normal operation (if such services are provided by the future operator), and (e) restricting entry of heavy vehicles during peak hours (7 a.m. to 10 a.m. and 4 p.m. to 7 p.m.) in weekdays, except for major events (i.e. with more than 20,000 persons).

3.9.11    The mitigation measures recommended above would help reduce the annual NO₂ emission but their benefits are not easily quantifiable for the purpose of evaluating the residual impact. As such, the residual impacts are evaluated based upon the assessment results which would potentially be further reduced when the future operator puts in place the mitigation measures as far as practicable during the project implementation stage.

3.9.12    Residual environmental impacts have been evaluated in accordance with the Section 4.4.3 of EIAO-TM. Assessment results show that the exceedances of annual average NO₂ are mainly resulted from the relatively high concentrations of background air pollution in Kowloon City and To Kwa Wan Districts, and the impact magnitude for changes in ambient pollutant concentrations due to the Project is considered minimal in the assessment area. With the implementation of the air quality improvement schemes currently being undertaken by the Government, continuous air quality improvement in the territory is expected. The small affected population in Year 2023 will further be reduced to a limited size in Year 2036. Based on the assessment results, similar population would be affected even without the Project. Through the evaluation of the residual environmental impacts in Sections 3.8.48 to 3.8.57, it is considered that the Project will not cause long term serious environmental implications.

3.9.13    In conclusion, the Project would not impose adverse air quality impact on the assessment area and the residual impacts are insignificant.