SA1 to Agreement No

4.3 Study Area and Air Sensitive Receivers

4.3.1 The study areas for the air quality assessment are defined by a distance of 500m from the boundary of the three RIWs. Owing to the proximity between the J/O New Clear Water Bay Road / Shun Lee Tsuen Road RIW and J/O Clear Water Bay Road / On Sau Road RIW, it is suggested to group these two RIWs together under the New Clearwater Bay Road RIW (NCWBR RIW) so as to assess the cumulative impacts. Regarding the J/O Sau Mau Ping Road/Lin Tak Road RIW (LTR RIW), it is located at a far distance (more than 500m from the NCWBR RIW) and the commission year would be different from the NCWBR RIW, thus, it is considered as a separate study area for assessment.

4.3.2 The study areas contain a mixture of existing residential buildings, future residential buildings, schools and commercial premises. Air sensitive receivers (ASRs) located in the vicinity of the 500m from the works boundary have been reviewed.

4.3.3 Planned/committed ASRs have been reviewed and updated by making reference to the latest Outline Zoning Plans (OZP), Layout Plans and other published plans in vicinity of the development, including:

Ÿ Ngau Tau Kok and Kowloon Bay Outline Zoning Plan (No. S/K13/28) dated April 2014;

Ÿ Kwun Tong South Outline Zoning Plan (No. S/K14S/20) dated July 2015;

Ÿ Kwun Tong North Outline Zoning Plan (No. S/K14N/14) dated June 2015;

Ÿ Tseng Lan Shue Outline Zoning Plan (No. S/SK-TLS/8) dated March 2006; and

Ÿ Tseung Kwan O Outline Zoning Plan (No. S/TKO/21) dated February 2015.

4.3.4 Representative ASRs in the vicinity of the three sites are selected for the assessment. Details of the representative ASRs for NCWBR RIW and LTR RIW are presented in the below Table 4.4 and Table 4.5, respectively and their locations are shown in Figure 4.1 and Figure 4.2.

Table 4.4 Description of Representative Air Sensitive Receivers (NCWBR RIW)

ASR ID	Description	Land Uses ⁽¹⁾	Max Height Above Ground (approx.) (m)	Distance from CWBR/OSR RIW Works Boundary (approx.) (m)	Distance from NCWBR/SLTR RIW Works Boundary (approx.) (m)
ASR ID	Description	Land Uses ⁽¹⁾	Max Height Above Ground (approx.) (m)	Distance from CWBR/OSR RIW Works Boundary (approx.) (m)
ACWE-18	Choi Wan (II) Estate Kai Fai House	R	84	>500	80
ACWE-5	Choi Wan (I) Estate Pak Hung House	R	84	>500	300
ACWE-9	Choi Wan (I) Estate	R	84	>500	200
AFNS-1	Fei Ngo Shan Road No.1	R	10	50	300
AFNS-10	Flamingo Garden Phase I	R	10	200	>500
AFNS-11	Flamingo Garden Phase I	R	10	200	>500
AFNS-2	Sienna Garden	R	10	10	450
AFNS-3	Sienna Garden	R	10	10	500
AFNS-4	Helena Heights	R	10	60	500
AFNS-5	Fei Ngo Shan Road No.6	R	10	50	500
AGHS-2	Good Hope School	S	27	>500	100
AGHS-3	Good Hope School	S	12	500	150
AKSP-1	CCC Kei Shun Special School	S	21	250	30
AKTG-01	Kwun Tong Government Secondary School	S	28	80	350
ALEP-01	Leighton Pavilion	R	15	70	500
ALWT-01	Lung Wo Tsuen	R	6	250	>500
ASCC-05	Shun Chi Court Shun Fung House	R	50	70	400
ASCC-10	Shun Chi Court Shun Cheung House	R	50	150	350
ASJA-1	St Joseph's Anglo Chinese School	S	21	>500	150
ASJA-2	St Joseph's Anglo Chinese School	S	21	>500	150
ASLD-10	Shun Lee Disciplined Services Quarters (Block 3)	R	117	450	10
ASLD-17	Shun Lee Disciplined Services Quarters (Block 6)	R	117	350	10
ASLE-04	Shun Lee Shopping Centre (Phase 1)	C	18	300	80
ASLE-13	Shun Lee Estate Park	O	1.5	400	90
ASLE-21	Shun Lee Estate Lee Hang House	R	45	250	30
ASLE-22	Shun Lee Estate Lee Ming House	R	45	250	20
ASLF-1	Shun Lee Fire Station	GIC	1.5	400	40
ASLP-1	Shun Lee Tsuen Playground	O	1.5	400	40
ASOA-1	Clear Water Bay Road Sitting Out Area	O	1.5	400	60
ASOE-01	Shun On Kindergarten	S	8	>500	300
ASOE-02	Shun On Estate On Chung House	R	80	450	250
ASOE-03	Shun On Estate On Chung House	R	80	450	300
ASYS-1	Sing Yin Secondary School	S	21	>500	250
ATPC-01	Tai Pan Court	R	9	20	>500
ATPC-02	Tai Pan Court	R	9	30	>500
AVDT-01	Clear Water Bay Village House	R	3	350	>500
Note:
(1) R: Residential; GIC: Government, Institution and Community; H: Clinic / Home for the aged / Hospital; S: School; O: Open Area/Playground; C: Commercial.

Table 4.5 Description of Representative Air Sensitive Receivers (LTR RIW)

ASR ID	Description	Land Uses ⁽¹⁾	Max Height Above Ground (approx.) (m)	Distance from LTR RIW Works Boundary (approx.) (m)
ASR ID	Description	Land Uses ⁽¹⁾	Max Height Above Ground (approx.) (m)	Distance from LTR RIW Works Boundary (approx.) (m)
AHTE-1	Hin Ting Estate Yan Tin House	R	84	10
AHTE-4	Hin Ting Estate Mei Tin House	R	84	10
AHTE-6	Hin Ting Estate Choi Tin House	R	84	10
AHTE-7	Hin Ting Estate	O	1.5	15
AHWC-03	Hong Wah Court Yee Hong House	R	104	10
ALTE-5	Lam Tin Estate Lam Fai House	R	112	80
ALTP-1	Lam Tin Park	O	1.5	120
ALTP-2	Lam Tin Park	O	1.5	100
ALTP-3	Lam Tin Park	O	1.5	60
ALTP-4	Lam Tin Park	O	1.5	200
APTE-03	Po Tat Estate Tat Cheung House	R	80	200
APTE-12	Po Tat Estate Tat Hei House	R	122	25
APTE-14	Po Tat Estate Tat Kai House	R	122	30
APTE-15	Po Tat Estate Tat Hin House	R	122	50
APTE-16	Po Tat Estate Tat On House	R	122	60
ASECP-2	St Edward's Catholic Prim School	S	21	10
ASMP-37	Sau Mau Ping South Estate Playground	O	1.5	200
ASMP-40	South Mau Ping (South) Estate Sau Mei House	R	112	150
ASMPR-1	Hiu Kwong Street Sitting Out Area	O	1.5	250
ATPN-21	Tsui Ping (South) Estate Tsui Chung House	R	84	300
ATPN-22	Tsui Ping (South) Estate Tsui Chung House	R	84	300
ATTPS-01	S.K.H. Tak Tin Lee Shiu Keung Primary School	S	21	100
ATTE-3	Tak Tin Estate Tak King House	R	60	15
ATTE-5	Tak Tin Estate Tak Shui House	R	84	250
ATTE-6	Tak Tin Estate Tak Yee House	R	84	150
ASPS-01	St. Paul’s School (Lam Tin)	S	21	220
DARD-11	Block 1, DAR Site D	R	82.4	400
DARE-27	Planned School, DAR Site E	S	32	400
AEPD-01	Environmental Protection Department’s Restored Landfill Site Office	O	10	10
ARQS-75 ⁽²⁾	Private Housing, ARQ Site R2-9	R	70	400
ARQS-77 ⁽²⁾	Private Housing, ARQ Site R2-10	R	70	400
Note:
(1) R: Residential; GIC: Government, Institution and Community; H: Clinic / Home for the aged / Hospital; S: School; O: Open Area/Playground; C: Commercial; W: Worship. (2) The planned private housing development at ARQ Site R2-9 & R2-10 (ARQS-75 & ARQS-77) which occupied after Year 2022, therefore, they are considered in the operational phase assessment only.

4.3.5 For operational phase impact assessment, six elevations are chosen for the assessment: 1.5m above local ground level (which is the average height of the human breathing zone), 5.0m, 10.0m, 15.0m, 20.0m and 25.0m above local ground level (mAG). For the construction phase impact assessment, three elevations, 1.5mAG, 5.0mAG and 10.0mAG are selected for assessment.

4.3.6 Air contours within the 500m assessment areas are prepared for the worst-hit level.

4.4 Identification of Environmental Impacts (Construction Phase)

Emissions from Construction Activities

4.4.1 The construction activities for the Project would be commenced in late 2016 and completed in early 2022 and the construction period would be around 60 months. The major construction activities are summarized as below:

· Mobilization and site clearance

· Demolition of existing structures

· Slope works

· Construction of retaining walls

· Carriageway/pavement construction including utility installation

· Construction of noise mitigation measures (foundation)

4.4.2 During this construction period, the following concurrent projects with construction works in the vicinity of the three RIW sites have been reviewed in terms of cumulative impacts and the assumptions on concurrent works are listed as follows:

· Development at Anderson Road (DAR) – the major construction of DAR would be completed in 2016, and the likelihood of cumulative impact with RIWs construction be low;

· Site formation and infrastructure works of ARQ Site Development and Pedestrian Connectivity – reference is made in accordance with the approved Schedule 3 EIA report (Register No.: AEIAR-183/2014). The major works would commence in early 2016 and anticipated to be completed by end 2020. Cumulative impact (including construction traffic) of ARQ Works under mitigated scenario in Year 2017 (worst case year) is taken into account in the cumulative impact assessment;

· Proposed Rock Cavern Development within ARQ – The construction for the Proposed Rock Cavern Development within ARQ will be started in 2018 and for completion in early 2020. It would have about 2 years overlapping works. The Rock Cavern is a Schedule 2 EIA project, and the potential impacts are assessed in a separate EIA study “Development of Anderson Road Quarry Site – Rock Cavern Development”. The cumulative impact of the Cavern under mitigated scenario is taken into account in the cumulative impact assessment.

Industrial Emission

4.4.3 A total of 4 chimneys were identified within the 500m assessment area of NCWBR RIW but no chimneys was identified within the 500m assessment area of LTR RIW based on the findings of the survey conducted in July 2015. Details of the locations and the emission inventory of these chimneys are shown in Appendix 4.1. The associated cumulative air quality impacts due to the chimney emissions during construction phase have been assessed.

Portal Emission

4.4.4 The tunnel portal of the Tseung Kwan O Tunnel on the Kowloon side is located within the 500m assessment area of the LTR RIW. Details of the locations and the emission inventory are shown in Appendix 4.2.

Vehicular Emission from Open Road

4.4.5 According to EPD’s Air Quality Report 2013, the major sources for Respirable Suspended Particulates (RSP) include power generation, road transport, etc. Thus, particulate matter generated from road traffic within 500m study area would also have cumulative air quality impact on nearby ASRs during construction phase. The associated cumulative air quality impacts (i.e. RSP and FSP) due to the vehicular emissions are assessed by CALINE4 model. Summary of Composite Vehicular Emission Factor used in the CALINE4 model is shown in Appendix 4.7.

4.5 Assessment Methodology (Construction Phase)

Emission Inventory for Dust Impact

4.5.1 Dust emission impact is predicted based on emission factors from USEPA Compilation of Air Pollution Emission Factors (AP-42), 5th Edition. The major dusty construction activities for the Project to be concerned and considered in the modelling assessment include:

· Demolition of existing structures

Excavation and material handlings within the construction site modelled as heavy construction activities

Wind erosion of open active site during non-working hours

· Slope work and construction of retaining walls

Excavation and material handlings within the construction site modelled as heavy construction activities

Wind erosion of open active site during non-working hours

· Carriageway/pavement construction including utility installation

Excavation, material handlings and backfilling within the construction site modelled as heavy construction activities

Wind erosion of open active site during non-working hours

· Construction of noise mitigation measures (foundation)

Excavation and material handlings within the construction site modelled as heavy construction activities

Wind erosion of open active site during non-working hours

Tier Assessment Approach

4.5.2 Works activities and plant would not be concentrated in certain areas of the site close to ASRs for an extended period of time during the construction period. However, notwithstanding that such a scenario would not be expected to occur, a hypothetical Tier 1 screening test assuming 100% active area of construction site of the Project with mitigation measures in place has been undertaken for predicting hourly and daily average TSP levels. It aims to highlight the hot spot locations where construction dust may potentially become an issue. However, it should be emphasized that Tier 1 screening test is a hypothetical one which is very conservative and does not occurred in reality.

4.5.3 The Tier 1 results have allowed a more focused Tier 2 assessment to be undertaken at the specific hot spot locations where TSP non-compliance is predicted under the Tier 1 screening test, a focused Tier 2 assessment is undertaken whereby the percentage of daily maximum active works areas (i.e. 15% for NCWBR RIW and 10% for LTR RIW, justifications for the percentage of active areas refer to Appendix 4.3) for the Project are positioned closest to the potentially worst affected ASRs.

4.5.4 In terms of the annual average prediction, the highest percentage active working area is less than 15% (NCWBR RIW) and 10% (LTR RIW) during any short period of time based on the engineers’ estimation (see Appendix 4.3). By following argument in Section 4.5.17, it is suggested that a 15% and 10% of hourly/daily assessment emission rates are adopted for the long-term annual predictions for RSP/FSP for NCWBR RIW and LTR RIW, respectively.

4.5.5 RSP and FSP emission factors for heavy construction and wind erosion are estimated based on the particle size distribution stated in Section 13.2.4.3 of USEPA. According to the particle size distribution, RSP (aerodynamic diameter ≦ 10 μm) and FSP (aerodynamic diameter ≦2.5 μm) constitute approximately 47% and 7% of the TSP (aerodynamic diameter ≦ 30 μm), respectively. Hence, conversion factors based on the particle size distribution are adopted to estimate the RSP and FSP emissions from TSP emission, respectively. The particle size distribution and conversion factors for RSR and FSP are tabulated in Table 4.6.

Table 4.6 Particle Size Distribution of Construction Dust

AQO Parameters	Particle Size (µm)	Particle Size Multiplier (k) in AP-42	Conversion Factor (Based on TSP emission)
FSP	< 2.5	0.053	= FSP / TSP = 0.053 / 0.74 = 0.0716 ~ 7%
RSP	< 10	0.35	= RSP / TSP = 0.35 / 0.74 = 0.473 ~ 47%
TSP	<30	0.74	-

4.5.6 The dust emission factors of the above construction activities for the Project are summarized in Table 4.7 below.

Table 4.7 Emission Factors for Dusty Construction Activities (Unmitigated Scenario)

Emission Source	Activity	Pollutant	Emission Factor	Remarks
Demolition of existing structures, Slope work and construction of retaining walls, Carriageway/pavement construction including utility installation, construction of noise barriers (foundation)	Heavy Construction Activities	TSP	E=2.69 Mg/hectare/month of activity	AP-42, Section 13.2.3
		RSP	E=1.27 Mg/hectare/month of activity	Referenced to USEPA, AP-42 Compilation of Air Pollution Emission Factors (AP-42), Section 13.2.4.3, 1^st Table, Conversion Factor for RSP based on TSP emission factors is 0.35/0.74 (refer to Table 4.6). Hence, emission factor 2.69 x 0.35 / 0.74 = 1.27 Mg/hectare/month of activity is adopted.
		FSP	E=0.193 Mg/hectare/month of activity	Referenced to USEPA, AP-42 Compilation of Air Pollution Emission Factors (AP-42), Section 13.2.4.3, 1^st Table, Conversion Factor for FSP based on TSP emission factors is 0.053/0.74 (refer to Table 4.6). Hence, emission factor 2.69 x 0.053 / 0.74 = 0.193 Mg/hectare/month of activity is adopted.
	Wind Erosion	TSP	E=0.85 Mg/hectare/year	AP-42, Section 11.9.4
		RSP	E=0.402 Mg/hectare/year	Referenced to USEPA, AP-42 Compilation of Air Pollution Emission Factors (AP-42), Section 13.2.4.3, 1^st Table, Conversion Factor for RSP based on TSP emission factors is 0.35/0.74 (refer to Table 4.6). Hence, emission factor 0.85 x 0.35 / 0.74 = 0.402 Mg/hectare/year of activity is adopted.
		FSP	E=0.0609 Mg/hectare/year	Referenced to USEPA, AP-42 Compilation of Air Pollution Emission Factors (AP-42), Section 13.2.4.3, 1^st Table, Conversion Factor for FSP based on TSP emission factors is 0.053/0.74 (refer to Table 4.6). Hence, emission factor 0.85 x 0.053 / 0.74 = 0.0609 Mg/hectare/year of activity is adopted.

4.5.7 For the prediction of the 10th highest daily average and annual average RSP and FSP concentrations, 12-hour (07:00-19:00) per normal working day is assumed for the construction period in the assessment. Since no construction activities would occur on Sundays and public holidays, only wind erosion would be assumed for these days as well as for other non-working hours (19:00 to 07:00 of the following day) on normal working days.

Dispersion Modelling & Concentration Calculation

4.5.8 The hourly meteorological data including wind speed, wind direction, and air temperature from the relevant grids from the MM5 Meteorological data (same basis for PATH model), are employed for the model run. The Pasquill stability class data are modelled separately using PC-Ramet model.

4.5.9 According to United States Environmental Protection Agency (USEPA) AP-42^{^[1]}, construction dust particles may be grouped into five particle size classes. Their size ranges are 1.25 mm, 3.75 mm, 7.5 mm, 12.5 mm, 22.5 mm, and the percentage of particles in each class is estimated to be 7%, 20%, 20%, 18% and 35%, respectively.

4.5.10 A Fugitive Dust Model (FDM) is used to assess the potential dust impact from construction activities. A height of 1.5m (the breathing level of human), 5m and 10m above ground would be adopted for the construction dust impact assessment. Air contour is prepared for the worst-hit level.

4.5.11 Vehicular emission from the major roads in the vicinity of the study area is also assessed. EMFAC-HK v2.6 for the worst-case assessment year (i.e. Year 2017 for NCWBR RIW and Year 2018 for LTR RIW) is used to calculate the vehicular tailpipe emission in lieu of the traditional fleet average emission factors. CALINE4 developed by the California Department of Transport is used to assess vehicular emissions impact from road network within the study area.

4.5.12 The tunnel portal of the Tseung Kwan O Tunnel on the Kowloon side is located within the 500m boundary of the LTR RIW. Therefore, the tunnel portal emission from Tseung Kwan O Tunnel at Kowloon side has been included in the near field model. As Tseung Kwan O Tunnel uses jet fans for ventilation, all the vehicular emission is assumed at the exit of the tunnel. ISCST3 model is used to assess the portal emissions as well as the emissions from the 4 chimneys identified within the 500m air quality assessment area of the NCWBR RIW.

4.5.13 PATH model is used to quantify the background air quality during the construction phase of the Project. The emission sources including those in Pearl River Delta Economic Zone, roads, marine, airport, power plants and industries within Hong Kong are all considered in the PATH model. The Year 2015 hourly data of background concentration predicted by the PATH model provided by EPD are adopted as background concentration in this study.

4.5.14 It is understood that only hourly RSP concentrations are available from PATH model. According to EPD’s “Guideline on the Estimation of PM2.5 for Air Quality Assessment in Hong Kong”, the conservative correction factors of 0.71 and 0.75 are applied on the annual and daily RSP concentration to generate annual and daily FSP concentration, respectively. For hourly background TSP concentration, it is considered reasonable to adopt hourly RSP concentrations from PATH as the ambient TSP background concentrations, as the particulate of sizes larger than 10 µm generated from far-field dust sources would have been largely settled before reaching the ASRs, which in turn most of the particulates from far-field sources affecting ASRs will likely be those less than or equal to 10 µm (i.e. RSP). For ease of reference, the substitution table is listed in Table 4.8.

Table 4.8 Background Substitution from PATH model 2015

Parameter	Background Concentration in PATH
1-hour TSP	RSP
Daily RSP	RSP
Annual RSP	RSP
Daily FSP	0.75 x RSP
Annual FSP	0.71 x RSP

Determination of Assessment Year (Construction Phase)

4.5.15 The construction period of the NCWBR RIW is from late 2016 to mid-2020 and LTR RIW is from late 2016 to early 2022. Sensitivity analysis of construction dust emission burden within works boundary is conducted in order to identify the worst case assessment year (with the highest emission burden) among these years. TSP which is the key pollutant in the construction phase is adopted for calculation based on the dust emission factors from USEPA Compilation of Air Pollution Emission Factors (AP-42), active working area and construction programme.

4.5.16 Based on engineer’s estimation, there would be less than 15% (NCWBR RIW) and 10% (LTR RIW) of active works areas in each work site during any short period of time. Hence the chance of having all 15% (NCWBR RIW) and 10% (LTR RIW) active works areas would be unlikely within an individual work site. Justifications for the percentage of active areas are presented in Appendix 4.3.

4.5.17 For annual average predictions, construction activities associated with the road improvement works would be moving work fronts spreading across the whole work site at any short period of time. With the compliance of Air Pollution Control (Construction Dust) Regulation, the requirements as stated in this regulation shall be fully implemented, e.g. other than active operating area, any excavated dusty materials or stockpile of dusty materials will be covered entirely by impervious sheeting. On this basis, it is reasonable to assume that the annual average active operating area would be similar to short term daily average active operating area (i.e. less than 15% for NCWBR RIW and 10% for LTR RIW) for potential dust emitting from both heavy construction and wind erosion. The active works area and TSP emission burden for various construction years are detailed in Appendix 4.4, and summarised in the Table 4.9.

Table 4.9 Establishment of Worst-year TSP Emission Burden

Year	Max Active Works Area (m²)	Annual TSP Emission (tonnes/year)
NCWBR RIW
2016	No physical construction works	0
2017	2,900	9.5 ⁽¹⁾
2018	1,580	5.2
2019	1,115	3.6
2020	72	0.1
LTR RIW
2016	No physical construction works	0
2017	950	3.1
2018	1,300	4.3⁽¹⁾
2019	480	1.6
2020	600	2.0
2021	500	1.6
2022	500	0.1

Note:

(1) The Worst-case year is identified as the year with the maximum emission TSP emission burden.

4.5.18 Based on the initial estimation, it is identified that Year 2017 is the worst-case year for NCWBR RIW and Year 2018 for LTR RIW on evaluation of construction dust cumulative impacts. The cumulative sources are listed in Table 4.10. Details of dust emission sources are shown in Appendix 4.5.

Table 4.10 Cumulative Dust Emission Sources at Worst-case Years

Emission	Cumulative Dust Sources
NCWBR RIW
Construction Dust (FDM)	Dust Sources from NCWBR RIW at the worst-case year (i.e. Year 2017) + Dust Sources from ARQ development and Pedestrian Connectivity at worst-case year (i.e. Year 2017) under the approved Schedule 3 EIA report (Register No.: AEIAR-183/2014) + Dust Source from ARQ Rock Cavern Development at worst-case year (i.e. Year 2018) in a separate undertaking Schedule 2 EIA
Open Road Emissions (CALINE4)	Open Road Emissions within 500m study area
Industrial Emissions/ Portal Emission (ISCST3)	Industrial chimneys within 500m study area
LTR RIW
Construction Dust (FDM)	Dust Sources from LTR RIW at the worst-case year (i.e. Year 2018) + Dust Sources from ARQ development and Pedestrian Connectivity at worst-case year (i.e. Year 2017) under the approved Schedule 3 EIA report (Register No.: AEIAR-183/2014)
Open Road Emissions (CALINE4)	Open Road Emissions within 500m study area
Industrial Emissions/ Portal Emission (ISCST3)	Portal Emissions from TKO Tunnel on the Kowloon side within 500m study area

Emission

Cumulative Dust Sources

NCWBR RIW

Construction Dust

(FDM)

Dust Sources from NCWBR RIW at the worst-case year (i.e. Year 2017) +

Dust Sources from ARQ development and Pedestrian Connectivity at worst-case year (i.e. Year 2017) under the approved Schedule 3 EIA report (Register No.: AEIAR-183/2014) +

Dust Source from ARQ Rock Cavern Development at worst-case year (i.e. Year 2018) in a separate undertaking Schedule 2 EIA

Open Road Emissions

(CALINE4)

Open Road Emissions within 500m study area

Industrial Emissions/

Portal Emission (ISCST3)

Industrial chimneys within 500m study area

LTR RIW

Construction Dust

(FDM)

Dust Sources from LTR RIW at the worst-case year (i.e. Year 2018) +

Dust Sources from ARQ development and Pedestrian Connectivity at worst-case year (i.e. Year 2017) under the approved Schedule 3 EIA report (Register No.: AEIAR-183/2014)

Open Road Emissions

(CALINE4)

Open Road Emissions within 500m study area

Industrial Emissions/

Portal Emission (ISCST3)

Portal Emissions from TKO Tunnel on the Kowloon side

within 500m study area

4.6 Prediction and Evaluation of Environmental Impacts (Construction Phase)

Unmitigated and Tier 1 Mitigated Scenarios – NCWBR RIW

4.6.1 For NCWBR RIW site, cumulative construction dust impact within the 500m assessment area has been evaluated. Under the unmitigated scenario, the predicted maximum 1-hour average TSP, the 10th highest daily average RSP and FSP, and annual average RSP and FSP concentrations at most of the representative ASRs in the vicinity of the sites would exceed the EIAO-TM criterion and AQOs. It is predicted the Project would have significant contribution on the both short-term (i.e. hourly or daily average) and long-term (i.e. annual average) TSP, RSP and FSP concentration.

4.6.2 In order to alleviate the potential dust impacts, hourly watering is considered to be applied for the active construction area with an assumption of dust removal efficiency of 87.5% (see Appendix 4.6). Under the mitigated scenario, it is predicted the Project would have minor contribution on the long term RSP and FSP concentration and the short term FSP concentration but would pose major contribution to short term TSP and RSP concentration during the worst-case hours or days within the assessment year. Nonetheless, the predicted maximum 1-hour TSP concentrations at all representative ASRs would still comply with the EIAO-TM requirement. At the same time, the predicted 10th highest daily average RSP and FSP, and the annual average RSP and FSP would comply with the AQOs criteria. Detailed assessment results for TSP, RSP and FSP are listed in Appendix 4.8 and the Table 4.11, Table 4.12 and Table 4.13 summarised the cumulative and project-contributed air pollutant concentration for the unmitigated scenario and Tier 1 mitigated scenario, respectively. There is no need to further conduct the Tier 2 assessment.

Table 4.11 Summary of TSP, RSP and FSP Concentrations - NCWBR RIW (Unmitigated Scenario)

Pollutant	Averaging Time	AQOs / Criteria of EIAO-TM (µg/m³) ⁽¹⁾	Concentration at Various Height (µg/m³) ^{(2) (3)}
			1.5m		5m		10m
			Cumulative⁽⁴⁾	Project⁽⁵⁾	Cumulative⁽⁴⁾	Project⁽⁵⁾	Cumulative⁽⁴⁾	Project ⁽⁵⁾
TSP	Max.1-hour	500	290 - 3004	230 - 2950	294 - 1558	234 - 1514	356 - 884	271 - 811
RSP	Max. Daily	100 (9)	112 – 335 (1-202)	<1 - 283	112 - 234 (1 – 146)	<1 - 130	111 - 184 (1 – 37)	<1 - 89
	10^th Highest Daily	100 (9)	78 - 258	<1 - 202	78 - 167	<1 - 118	78 - 115	<1 - 59
	Annual	50	41 - 53	<1 - 11	41 - 48	<1 - 6	41 - 45	<1 - 3
FSP	Max. Daily	75 (9)	84 – 119 (1 - 23)	<1 - 39	84 – 107 (1 – 4)	<1 - 17	84 – 99 (1 – 1)	<1 - 10
	10^th Highest Daily	75 (9)	55 - 79	<1 - 42	55 – 67	<1 - 18	55 – 62	<1 - 5
	Annual	35	29 - 32	<1 - 2	29 - 31	<1	29 - 30	<1

Note:

(1) Values in ( ) mean the number of exceedances allowed per year.

(2) Values which exceeded the AQO or criterion of EIAO-TM are shown as bolded characters.

(3) Values in ( ) mean the number of exceedance against the AQOs predicted.

(4) Cumulative stands for the predicted cumulative air pollutant concentration.

(5) Project stands for the predicted air pollutant concentration contributed by the Project itself.

Table 4.12 Summary of TSP, RSP and FSP Concentrations - NCWBR RIW (Tier 1 Mitigated Scenario)

Pollutant	Averaging Time	AQOs / Criteria of EIAO-TM (µg/m³) ⁽¹⁾	Concentration at Various Height (µg/m³) ^{(2) (3)}
			1.5m		5m		10m
			Cumulative ⁽⁴⁾	Project ⁽⁵⁾	Cumulative⁽⁴⁾	Project ⁽⁵⁾	Cumulative⁽⁴⁾	Project ⁽⁵⁾
TSP	Max.1-hour	500	151 - 470	<1 - 369	151 - 254	<1 - 174	151 - 187	<1 - 101
RSP	Max. Daily	100 (9)	112 – 147 (1 – 4)	<1 - 27	112 - 135 (1 – 2)	<1 - 16	111 - 127 (1 – 1)	<1 - 9
RSP	10^th Highest Daily	100 (9)	74 – 93	<1 - 29	74 – 84	<1 - 11	74 - 82	<1 - 5
FSP	Max. Daily	75 (9)	84 - 94 (1 – 1)	<1 - 4	84 – 92 (1 – 1)	<1 - 2	84 – 91 (1 – 1)	<1 - 1
FSP	10^th Highest Daily	75 (9)	55 – 61	<1 - 3	55 – 60	<1 - 2	55 - 59	<1

Note:

(1) Values in ( ) mean the number of exceedances allowed per year.

(2) Values which exceeded the AQO or criterion of EIAO-TM are shown as bolded characters.

(3) Values in ( ) mean the number of exceedance against the AQOs predicted.

(4) Cumulative stands for the predicted cumulative air pollutant concentration.

(5) Project stands for the predicted air pollutant concentration contributed by the Project itself.

Table 4.13 Long term assessment – Summary of Annual RSP and FSP concentration results – NCWBR RIW (Mitigated scenario)

Pollutant	Averaging time	AQOs (µg/m³)	Concentration at Various Height (µg/m³)
			1.5m		5m		10m
			Cumulative ⁽¹⁾	Project ⁽²⁾	Cumulative ⁽¹⁾	Project ⁽²⁾	Cumulative ⁽¹⁾	Project ⁽²⁾
RSP	Annual	50	40 - 44	<1 - 2	40 - 43	<1	40 - 42	<1
FSP	Annual	35	28 - 30	<1	28 - 30	<1	28 - 30	<1

Note:

(1) Cumulative stands for the predicted cumulative concentration.

(2) Project stands for the predicted concentration contributed by the Project itself.

4.6.3 The contour plots for 1-hour average TSP, 10th highest daily average RSP and FSP and annual average RSP and FSP at the worst hit level, 1.5m above ground, under unmitigated and mitigated scenarios are shown in Figures 4.3 – 4.12.

Unmitigated and Tier 1 Mitigated Scenarios – LTR RIW

4.6.4 For LTR RIW site, the cumulative construction dust impact within the 500m assessment area has been evaluated. Under the unmitigated scenario, the predicted maximum 1-hour average TSP, daily average RSP and FSP, and annual average RSP and FSP concentrations at most of the ASRs in the vicinity of the sites would exceed the EIAO-TM criterion and AQOs. It is predicted the Project would have major contribution on the both short-term (i.e. hourly or daily average) and long-term (i.e. annual average) TSP, RSP and FSP concentration.

4.6.5 In order to alleviate the potential dust impacts, hourly watering is considered to be applied for the active construction area with an assumption of dust removal efficiency of 87.5% (see Appendix 4.6).

4.6.6 Based on the results of the Tier 1 screening test as presented in Appendix 4.9, it is predicted the Project would have minor contribution on the long term RSP and FSP concentration and the short term FSP concentration after implementation of proposed dust suppression measure. However, the Project would still pose major contribution to short term TSP and RSP concentration at some ASRs during the worst-case hours or days within the assessment year. The predicted maximum hourly TSP levels at ASRs DARE-27 and ASECP-2 and the 10^th highest daily average RSP levels at ASRs DARE-27, ATTE-3, AHTE-4 and ASECP-2 would still exceed the criteria stipulated in EIAO-TM and the AQOs. Nonetheless, the predicted daily average FSP and annual average RSP and FSP levels at all representative ASRs would comply with the criteria stipulated in AQO. Detailed assessment results for TSP, RSP and FSP are listed in Appendix 4.9 and the Table 4.13, Table 4.14 and Table 4.15 summarise the cumulative and project-contributed air pollutant concentration for the unmitigated scenario and Tier 1 mitigated scenario.

Table 4.14 Summary of TSP, RSP and FSP Concentrations - LTR RIW (Unmitigated Scenario)

Pollutant	Averaging Time	AQOs / Criteria of EIAO-TM (µg/m³) ⁽¹⁾	Concentration at Various Height (µg/m³) ^{(2) (3)}
			1.5m		5m		10m
			Cumulative ⁽⁴⁾	Project ⁽⁵⁾	Cumulative⁽⁴⁾	Project ⁽⁵⁾	Cumulative⁽⁴⁾	Project ⁽⁵⁾
TSP	Max.1-hour	500	410 - 4255	<1 - 4216	427 - 2559	366 - 2500	384 - 1308	299-1248
RSP	Max. Daily	100 (9)	113 – 505 (3 - 288)	<1 - 456	114 – 324 (3 - 276)	<1 - 275	113 – 204 (3 - 144)	<1 - 168
	10^th Highest Daily	100 (9)	90 – 433	<1 - 376	93 – 287	<1 - 219	90 – 181	<1 - 114
	Annual	50	40 - 56	<1 - 15	40 - 50	<1 - 9	40 - 45	<1 - 5
FSP	Max. Daily	75 (9)	84 - 115 (1 - 100)	<1 - 63	84 – 100 (1 - 30)	<1 - 36	84 – 93 (1 - 3)	<1 - 9
	10^th Highest Daily	75 (9)	59 – 100	<1 - 58	60 – 81	<1 - 31	59 – 70	<1 - 20
	Annual	35	28 - 31	<1 - 2	28 - 30	<1 - 1	28 - 30	<1

Note:

(1) Values in ( ) mean the number of exceedances allowed per year.

(2) Values which exceeded the AQO or criterion of EIAO-TM are shown as bolded characters.

(3) Values in ( ) mean the number of exceedance against the AQOs predicted.

(4) Cumulative stands for the predicted cumulative concentration.

(5) Project stands for the predicted concentration contributed by the Project itself.

Table 4.15 Summary of TSP, RSP and FSP Concentrations - LTR RIW (Tier 1 Mitigated Scenario)

Pollutant	Averaging Time	AQOs / Criteria of EIAO-TM (µg/m³) ⁽¹⁾	Concentration at Various Height (µg/m³) ^{[2] [3]}
			1.5m		5m		10m
			Cumulative ⁽⁴⁾	Project ⁽⁵⁾	Cumulative⁽⁴⁾	Project ⁽⁵⁾	Cumulative⁽⁴⁾	Project ⁽⁵⁾
TSP	Max. 1-hour	500	154 - 594	<1 - 502	154 - 382	<1 - 313	152 - 251	<1 - 156
RSP	Max. Daily	100 (9)	113 - 141 (1 - 56)	<1 - 55	113 - 128 (1 - 14)	<1 - 15	113 - 121 (1 - 3)	<1 - 8
RSP	10^th Highest Daily	100 (9)	79 – 115	<1 - 53	80 – 101	<1 - 33	80 – 93	<1 - 16
FSP	Max. Daily	75 (9)	84 – 89 (1 - 1)	<1 - 4	84 – 87 (1 - 1)	<1 - 2	84 - 86 (1 - 1)	<1 - 1
FSP	10^th Highest Daily	75 (9)	57 – 62	<1 - 5	58 – 61	<1 - 2	58 – 59	<1 - 2

Note:

(1) Values in ( ) mean the number of exceedances allowed per year.

(2) Values which exceeded the AQO or criterion of EIAO-TM are shown as bolded characters.

(3) Values in ( ) mean the number of exceedance against the AQOs predicted.

(4) Cumulative stands for the predicted cumulative concentration.

(5) Project stands for the predicted concentration contributed by the Project itself.

Table 4.16 Long term assessment – Summary of Annual RSP and FSP concentration results – LTR RIW (Mitigated scenario)

Pollutant	Averaging time	AQOs (µg/m³)	Concentration at Various Height (µg/m³)
			1.5m		5m		10m
			Cumulative ⁽¹⁾	Project ⁽²⁾	Cumulative ⁽¹⁾	Project ⁽²⁾	Cumulative ⁽¹⁾	Project ⁽²⁾
RSP	Annual	50	40 - 43	<1 - 2	40 - 42	<1 - 1	40 - 42	<1
FSP	Annual	35	28 – 30	<1	28 - 29	<1	28 – 29	<1

Note:

(1) Cumulative stands for the predicted cumulative concentration.

(2) Project stands for the predicted concentration contributed by the Project itself.

4.6.7 The contour plots for maximum 1-hour average TSP, 10th highest daily average RSP and FSP and annual average RSP and FSP at the worst hit level, 1.5m above ground, under unmitigated and mitigated scenarios are shown in Figures 4.13 – 4.22.

Tier 2 Assessment – LTR RIW

4.6.8 Four ASRs (DARE-27, ATTE-3, AHTE-4 and ASECP-2) where the predicted maximum 1-hour average TSP or the 10^th highest daily average RSP non-complied to the EIAO-TM or AQO criteria under the Tier 1 screening test are selected to undergo the Tier 2 assessment. The assessment results of Tier 2 test are detailed in Appendix 4.9 and the cumulative and project-contributed air pollutant concentration are summarised in Table 4.17 and Table 4.18. Based on the results of the Tier 2 assessment, it is predicted that cumulative maximum hourly average TSP at ASRs DARE-27 and ASECP-2 and the 10^th highest daily RSP levels at ASRs DARE-27, ATTE-3, AHTE-4 and ASECP-2 would comply with the EIAO-TM criterion and AQOs.

Table 4.17 Summary of 1-hour TSP Concentrations of concerned ASRs - LTR RIW (Tier 2 Mitigated Scenario)

Location	ASR ID	Max. 1-hour Ave. TSP concentrations at various height (µg/m³) (EIAO-TM Criterion = 500 µg/m³)
		1.5m		5m		10m
		Cumulative ⁽¹⁾	Project ⁽²⁾	Cumulative ⁽¹⁾	Project ⁽²⁾	Cumulative ⁽¹⁾	Project ⁽²⁾
Planned School, DAR Site E	DARE-27	415	<1	220	<1	155	<1
St Edward's Catholic Primary School	ASECP-2	445	377	225	142	149	52

Note:

(1) Cumulative stands for the predicted cumulative concentration.

(2) Project stands for the predicted concentration contributed by the Project itself.

Table 4.18 Summary of Daily RSP Concentrations of concerned ASRs - LTR RIW (Tier 2 Mitigated Scenario)

Location	ASR ID		Max. Daily Ave. RSP Concentration (μg/m³)⁽¹⁾			The 10^th highest Daily Ave. RSP Concentration (μg/m³)
Location	ASR ID		1.5m	5m	10m	1.5m	5m	10m
Hin Ting Estate Mei Tin House	AHTE-4	Cumulative ⁽²⁾	118 (5)	115 (1)	113 (1)	93	84	82
Hin Ting Estate Mei Tin House	AHTE-4	Project ⁽³⁾	5	2	<1	16	15	<1
St Edward's Catholic Prim School	ASECP-2	Cumulative ⁽²⁾	115 (7)	113 (1)	113 (1)	99	86	82
St Edward's Catholic Prim School	ASECP-2	Project ⁽³⁾	2	<1	<1	27	6	<1
Planned School, DAR Site E	DARE-27	Cumulative ⁽²⁾	117 (7)	115 (1)	114 (1)	98	86	82
Planned School, DAR Site E	DARE-27	Project ⁽³⁾	<1	<1	<1	<1	<1	<1
Tak Tin Estate Tak King House	ATTE-3	Cumulative ⁽²⁾	114 (3)	113 (2)	113 (1)	93	86	83
Tak Tin Estate Tak King House	ATTE-3	Project ⁽³⁾	1	<1	<1	25	14	<1

Note:

(1) The AQO for daily average RSP is 100μg/m³ and the number of exceedance allowed per year is 9. Values in ( ) mean the number of exceedance against the AQOs predicted.

(2) Cumulative stands for the predicted cumulative concentration.

(3) Project stands for the predicted concentration contributed by the Project itself.

4.6.9 Tier 2 assessment contour plots of cumulative maximum hourly average TSP and daily average RSP concentrations at 1.5mAG are presented in Figures 4.23a, 4.23b, 4.24a, 4.24b, 4.24c. From the contour plots of Tier 2 assessment, it is found that no land lots with air sensitive uses are located within the exceedance zone at 1.5mAG.

4.7 Recommended Mitigation Measures on NCWBR RIW and LTR RIW (Construction Phase)

4.7.1 As mentioned in Section 4.6, the watering frequency is assumed to be once per hour and the watering application intensity is estimated to be 0.0455 L/m² so as to achieve a dust removal efficiency of 87.5%.

4.7.2 The following standard dust suppression measures will be suggested. They should be incorporated by the Contractor as a General Specification to control the dust nuisance throughout the construction phase:

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

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

Ÿ A stockpile of dusty material should not extend beyond the pedestrian barriers, fencing or traffic cones;

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

Ÿ Where practicable, vehicles washing facilities including a 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;

Ÿ When there are open excavation and reinstatement works, hoarding of not less than 2.4m high should be provided as far as practicable along the site boundary with provision for public crossing. Good site practice shall also be adopted by the Contractor to ensure the conditions of the hoardings are properly maintained throughout the construction period;

Ÿ The portion of any road leading only to construction site that is within 30m of a vehicle entrance or exit should be kept clear of dusty materials;

Ÿ 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;

Ÿ Any area that involves demolition activities should be sprayed with water or a dust suppression chemical immediately prior to, during and immediately after the activities so as to maintain the entire surface wet;

Ÿ 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;

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

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

Ÿ Cement or dry PFA delivered in bulk should be stored in a closed silo fitted with an audible high level alarm which is interlocked with the material filling line and no overfilling is allowed; and

Ÿ 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.

4.8 Evaluation of Residual Environmental Impacts (Construction Phase)

4.8.1 No excessive residual impact is anticipated for the Project during construction phase.

4.9 Identification of Environmental Impacts (Operational Phase)

4.9.1 Vehicular emission comprises a number of pollutants, including Nitrogen Oxides (NOx), Respirable Suspended Particulates (RSP), Fine Suspended Particulates (FSP), Sulphur Dioxides (SO₂), Carbon Monoxide (CO), Lead (Pb), Toxic Air Pollutants (TAPs), etc. According to “An Overview on Air Quality and Air Pollution Control in Hong Kong” ^[[2]^]published by EPD, one of the major air pollution issues is the local street-level pollution. Diesel vehicles are the main source of street-level pollution. The levels of suspended particulates (RSP/FSP) and nitrogen dioxide (NO₂) at the roadside in Hong Kong have been exceeding the Air Quality Objectives over the years. Motor vehicles, especially diesel vehicles, are the main sources of these pollutants at street level in Hong Kong. For other pollutants, due to the low concentration in vehicular emission, they are not considered as key pollutants for the purpose of this study.

Nitrogen Dioxide (NO₂)

4.9.2 Nitrogen oxides (NOx) is a major pollutant from fossil fuel combustion. According to the 2013 Hong Kong Emission Inventory Report published by EPD, marine vessels and public electricity generation are the largest NOx emission source and each accounted for 31% of the total emission in 2013. Vehicles were also a major NOx emission source, accounting for 23% of the total.

4.9.3 In the presence of O₃ and VOC, NOx would be converted to NO₂. Increasing traffic flow would inevitably increase the NOx emission and subsequently the roadside NO₂ concentration. Hence, NO₂ is one of the key pollutants for the operational air quality assessment of the Project. 1-hour and annual averaged NO₂ concentrations at each identified ASRs would be assessed and compared with the relevant new AQO to determine the compliance.

Respirable Suspended Particulates (RSP)

4.9.4 Respirable Suspended Particulates (RSP) refers to suspended particulates with a nominal aerodynamic diameter of 10µm or less. According to the 2013 Hong Kong Emission Inventory Report published by EPD, marine vessels is the largest RSP emission source and accounted for 36% of the total emissions in 2013. Road transport is also a major RSP emission source, accounting for 18% of the total emission in 2013.

4.9.5 Increasing traffic flow would inevitably increase the roadside RSP concentration. Hence, RSP is also key pollutants for the operational air quality assessment of the Project. The daily and annual averaged RSP concentrations at each identified ASR would be assessed and compared with the relevant new AQO to determine the compliance.

Fine Suspended Particulates (FSP)

4.9.6 Fine Suspended Particulates (FSP) refers to suspended particulates with a nominal aerodynamic diameter of 2.5µm or less. According to the 2013 Hong Kong Emission Inventory Report published by EPD, navigation became the largest FSP emission source and accounted for 43% of the total emissions in 2013. Road transport is also a major FSP emission source, accounting for 21% of the total emission in 2013.

4.9.7 Similar to the RSP, increasing traffic flow would increase the roadside FSP. Hence, FSP is also key pollutants for the operational air quality assessment of the Project. The daily and annual averaged FSP concentrations at each identified ASR would be assessed and compared with the relevant new AQO to determine the compliance.

Sulphur Dioxide (SO₂)

4.9.8 Sulphur dioxide (SO₂) is formed primarily from the combustion of sulphur-containing fossil fuels. In Hong Kong, power stations and marine vessels are the major sources of SO₂, followed by fuel combustion equipment and motor vehicles.^[[3]^] SO₂ emission from vehicular exhaust is due to the sulphur content in diesel oil. According to the 2013 Hong Kong Emission Inventory Report released by EPD, SO₂ emissions from vehicles had been substantially reduced (<1% of total) after the introduction of Euro V diesel from Dec 2007, whose sulphur content is capped at 0.001%. Similarly, industrial sector and construction had been using Euro V diesel since 2009.

4.9.9 In view that road transport only contributes a very small amount of SO₂ emission, relatively low measured concentrations and the adoption of low-sulphur and ultra-low-sulphur fuel under the existing government policy, SO₂ would not be a critical air pollutant of concern.

Carbon Monoxide (CO)

4.9.10 Carbon Monoxide (CO) is a typical pollutant emitted from fossil fuel combustion and comes mainly from vehicular emissions. With reference to the “Air Quality in Hong Kong 2013”, measured the highest 1-hour average (4,070 µg/m³) and the highest 8-hour average (2,860 µg/m³) were both recorded at the Causeway Bay roadside station; these values were around one eighth and one third of the respective AQO limits. In view that there is still a large margin to the AQO, CO would not be a critical air pollutant of concern.

Ozone (O₃)

4.9.11 Ozone (O₃) is produced from photochemical reaction between NOx and VOCs in the presence of sunlight, which will not be generated by this Project. Concentration of O₃ is governed by both precursors and atmospheric transport from other areas. When precursors transport along under favourable meteorological conditions and sunlight, ozone will be produced. This explains why higher ozone levels are generally not produced in the urban core or industrial area but rather at some distance downwind after photochemical reactions have taken place. In the presence of large amounts of NOx in the roadside environment, O₃ reacts with NO to give NO₂ and thus results in O₃ removal. O₃ is therefore not considered as a key air pollutant for the operational air quality assessment of a road project.

Lead (Pb)

4.9.12 The sale of leaded petrol has been banned in Hong Kong since April 1999. According to the “Air Quality in Hong Kong 2013”, the measured ambient lead concentrations were ranging from 4 ng/m³ to 100 ng/m³. The measured concentrations were well below the AQO limits of 1,500 ng/m³. Therefore, lead is not considered as a critical air pollutant of concern.

Toxic Air Pollutants (TAPs)

4.9.13 Vehicular exhaust is one of the emission sources of Toxic Air Pollutants (TAPs), which are known or suspected to cause cancer or other serious health and environmental effects. With reference to EPD’s Assessment of Toxic Air Pollutant Measurements in Hong Kong Final Report ^[[4]^], monitored TAPs in Hong Kong include diesel particulate matters (DPM), toxic elemental species, dioxins, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), carbonyls, and volatile organic compounds (VOCs). According to the results of Assessment of Toxic Air Pollutant Measurements in Hong Kong Final Report and Sources of PCB emissions ^[[5]^], vehicular emission is not considered as primary source of dioxins, PCBs, carbonyls and most toxic elemental species in Hong Kong. Therefore, these pollutants are not considered as key pollutants for quantitative assessment for the operation phase of a road project.

Diesel Particulate Matters (DPM)

4.9.14 Diesel Particulate Matters (DPM), as part of the overall Respirable Suspended Particulates (RSP), is one of the most important parameter contributing to the overall health risk of the population. Local vehicular emission is one of the major sources of DPM.

4.9.15 EPD has embarked on the following three key programmes to reduce the diesel particulate level at the roadside ^[[6]^]: (a) the LPG taxi and light bus program; (b) the introduction of an advanced test to check diesel vehicle smoke emission; and (c) the retrofit of pre-Euro diesel commercial vehicles with diesel oxidation Catalysts (DOCs). According to EPD’s website ^[[7]^], franchised bus companies have also retrofitted their Euro I buses with diesel oxidation catalysts (DOCs) and Euro II and III buses with diesel particulate filters (DPFs). A DPF can reduce particulate emissions from diesel vehicles by over 80%.

4.9.16 As recommended by EPD’s Assessment of Toxic Air Pollutant Measurements in Hong Kong Final Report, elemental carbon (EC) is used as a surrogate for DPM, and with reference to Measurements and Validation for the 2008/2009 Particulate Matter Study in Hong Kong ^[[8]^], EC showed a significant decrease in concentration from 2001 to 2009 in Hong Kong, i.e. -47.5%, -30.0% and -28.3% at Mong Kok, Tsuen Wan and Hok Tsui Monitoring Sites, respectively. With the continual efforts by EPD to reduce particulate emission from the vehicular fleet, a discernible decreasing trend is noted in the level of particulate matter. Therefore, DPM is not selected as representative pollutant for quantitative assessment for this project.

Polycyclic Aromatic Hydrocarbons (PAHs)

4.9.17 Polycyclic Aromatic Hydrocarbons (PAHs) are organic compounds of two or more fused benzene rings, in liner, angular or cluster conformations. Local vehicular traffic is also an important source of PAHs. For this group, the most important TAP is Benzo[a]pyrene, and it is often selected as a marker for the PAHs^[^{^[9]}^]. The EU Air Quality Standards for PAHs (expressed as concentration of Benzo[a]pyrene) is 1 ng/m³ for annual average^[[10]^]. With reference to “Air Quality in Hong Kong 2013”, annual average concentrations of PAHs (Benzo[a]pyrene) measured at EPD’s TAP monitoring stations (Tsuen Wan and Central/Western) were 0.15 ng/m³and 0.12 ng/m³, which is far below the EU Standards. Thus, PAHs are not considered as key pollutants for quantitative assessment for this project.

Volatile Organic Compounds (VOCs)

4.9.18 Volatile Organic Compounds (VOCs) are of great concern due to the important role played by them in a range of health and environmental problems. The US EPA has designated many VOC, including those typically found in vehicular emission, as air toxic. According to Assessment of Toxic Air Pollutant Measurements in Hong Kong Final Report, among the VOC compounds, benzene and 1,3-butadiene are the most significant ones for Hong Kong The UK Air Quality Standards for benzene and 1,3-butadiene are 5.0µg/m³ and 2.25 µg/m³ respectively^[[11]^]. Accordingly to “Air Quality in Hong Kong 2013”, annual average concentrations of benzene and 1,3-butadiene at EPD’s TAP monitoring stations (Tsuen Wan and Central/Western) were both 0.06 µg/m³ on annual average, which is far below the UK Standards. Thus, VOCs are not considered as key pollutants for quantitative assessment for this project.

4.10 Assessment Methodology (Operational Phase)

Determination of Assessment Year

4.10.1 From Section 4.9, it is anticipated that NO_2, RSP and FSP are the key pollutants to be considered in this Project during operation phase. In general, the assessment year for these air pollutants would be identified as the year with the highest emission strength induced within the assessment area.

4.10.2 The NCWBR RIW and LTR RIW would be in commissioning at 2020 and 2022, respectively. Together with the connecting traffic at existing highways within the assessment area, the traffic volume would increase gradually from 2020 to 2035/2037 (future 15 years after commissioning). In terms of typical development project, the traffic flow pattern would be dominant by two factors; namely: (1) the existing major roads (district distributor or expressway) within 500m study area; and (2) the traffic induced from the population intake. In terms of the future traffic projection, the latest planning parameters have been updated based on 2011-based TPEDM data. It is understood that the emission burden after 2031 would be significantly reduced due to replacement of old diesel commercial vehicles in the entire Hong Kong. Thus, sensitivity analysis of vehicular emission has been conducted by the EMFAC model (version 2.6) to identify the worst case assessment year (with the highest emission burden) among the following years. The traffic flows of the following years have been endorsed by TD. The operation of East Kowloon Line (EKL) has taken into account in the traffic forecast in accordance with “Railway Development Strategy 2014”.

· 2020 (commission year of NCWBR RIW)

· 2022 (commission year of LTR RIW);

· 2024;

· 2026;

· 2031 – with EKL;

· 2035 (15-year future after commissioning of NCWBR RIW) – with EKL and

· 2037 (15-year future after commissioning of LTR RIW) – with EKL.

Based on the above parameters, the EMFAC emission burdens for the NCWBR RIW and LTR RIW are listed in Appendix 4.10.

Evaluation of Operational Air Quality Impact

4.10.3 In accordance with EPD’s “Guidelines on Assessing the 'TOTAL' Air Quality Impacts (revised version on Mar 2013)”, emission sources could be classified into 3 categories as follows, depending on their distance from the concerned site:

· Primary contributions: project induced;

· Secondary contributions: pollutant-emitting activities in the immediate neighbourhood. For most local scale projects, any emission sources in an area within 500 m radius of the project site with notable impacts should be identified and included in an air quality assessment to cover the short-range contributions using EPD’s approved local-scale Gaussian type model; and

· Other contributions: pollution not accounted for by the previous two. PATH (Pollutants in the Atmosphere and their Transport over Hong Kong) model has been adopted to estimate future concentrations.

4.10.4 PATH is a regional air quality model developed by EPD to simulate air quality over Hong Kong against the Pearl River Delta (PRD) as background. PATH is set up on a three-dimensional grid system with horizontal nesting. For EIA applications, it simulates wind field, pollutant emissions, transportation and chemical transformation and outputs pollutant concentrations over Hong Kong and the PRD region at a fine grid size of 1.5km in both the N-S and E-W direction. The thickness of the first model layer can be taken to be 20m. PATH model is used to quantify the background air quality during the operational phase of the Project. Emission sources including roads, marine, airports, power plants and industries within the Pearl River Delta Economic Zone and Hong Kong are considered in the PATH model. Details of the PATH Model and related emission inventory can be found in EPD’s web site. As described in the revised “TOTAL’ Air Quality Guidelines, the relevant outputs of the PATH systems are gridded meteorological and pollutant concentration data every hour of the simulation period.

4.10.5 The following approach has been adopted for the operational phase cumulative air quality impact assessment:

· Use a regional air quality prediction model developed by EPD (PATH Dec 2012 version) to quantify the impacts from various pollution sources.

· Use Gaussian dispersion models i.e. CALINE4 for line sources (open road) and ISCST3 for point and area sources (portal and ventilation building, if any) to quantify the air quality impacts.

· The PATH model results have been added to the sum of the CALINE4 and ISCST3 model results sequentially on an hour-to-hour basis to derive the short-term and long-term cumulative impacts at the ASRs. The maximum hourly, daily and annual average results have then been calculated in accordance with the Title 40, Code of Federal Regulations, US Environmental Protection Agency (USEPA 40 CFR) Part 51 “Revision to the Guideline on Air Quality Models, Version 2005”. The pollutant concentration predicted at an ASR amongst the 8,760 hours (a year) have been ranked/ averaged to calculate the cumulative impact. The number of exceedances for each ASR has been counted and compared with the acceptance values in the prevailing AQO criteria.

Calculations of cumulative results and number of exceedance

Concurrent Projects (Secondary Contributions)

4.10.6 NCWBR RIW and LTR RIW will be commissioning at Year 2020 and Year 2022, respectively. In terms of cumulative impacts, the following projects have been reviewed whether it is considered in the assessment.

· Development at Anderson Road (DAR) – the major cumulative impact would be associated with vehicular emission within the roads of the DAR. Vehicular emissions from DAR Site within the 500m assessment areas will be taken in account.

· ARQ Site Development – the major cumulative impact would be associated with vehicular emission within the roads of the Anderson Road Quarry Site. Vehicular emissions from the ARQ site within the 500m assessment areas will be taken in account.

· Proposed Rock Cavern Development within ARQ– based on the latest design information, the Rock Cavern Development (under a separate Schedule 2 EIA project) covers one cavern (at +200mPD) only which will be used for exhibition area/resource centre at Quarry Park. Air pollutants emissions from the exhibition area/resource centre would be not anticipated. The traffic flow induced from this cavern development would be very limited and insignificant impact is anticipated.

· Pedestrian Connectivity – no air emissions generated during operation phase.

Emission from Open Road Traffic

4.10.7 The principal pollutants associated with traffic emission are NO₂, RSP and FSP. The EMFAC-HK v2.6 is used to calculate the vehicular emission burden for period between Year 2020/2035 for NCWBR RIW and Year 2022/2037 for LTR RIW. The worst-case year emission rates is determined, based on the highest emission burden induced within the assessment area. The input parameters and model assumptions made in EMFAC-HK model are summarized as follows:

· Referring to the EPD’s Guideline on Modelling Vehicle Emissions, “Burden mode” has been used for calculating area-specific emission inventories. It is selected for this Project, since it can provide hourly vehicular emissions, taking into account of ambient conditions and speeds combined with vehicle activity, i.e. the number of vehicles, the kilometers driven per day and the number of daily trips.

· Each vehicle class has diverse technological factors in different years. According to the underlying assumption in the EMFAC-HK model, each vehicle class can be modelled by the individual behaviour of the unique technology groups. Each technology group represents the vehicles from the same class but has distinct emission control technologies and has similar in-use deterioration rates and respond the same to repair. It means that the vehicles from the same class have the same emission standards or specific equipment installed in them (e.g. multi-port fuel injection, three-way catalyst, adaptive fuel controls, etc.) which make them have the same performance.

· According to EPD’s Guideline on Modelling Vehicle Emissions - Appendix 2, the implementation schedules of Euro V and Euro VI standards are in the middle of a year for some vehicle classes or fuel types. Since the detailed fraction data is not available after Year 2010, as a conservative approach, the exhaust technology fractions of these vehicle classes or fuel types are assumed to be kept as the previous standards fully for the scheduled year, while upgraded to the higher standards fully at the following year. Evaporative technology fraction in the model is based on the default value.

· As recommended in the EPD’s Guideline on Modelling Vehicle Emissions, default vehicle populations forecast in EMFAC-HK is used.

· The default accrual rates in EMFAC-HK are estimated from the local mileage data adjusted to reflect the total VKT for each vehicle class. The default value has been used.

· For those roads with cold starts, the diurnal variation of daily trips in the assessment area for the highest predicted traffic flow within 15 years upon the commissioning year of the Project applied in the EMFAC-HK model is provided by the traffic team.

· Vehicle-kilometer-travelled (VKT) represents the total distance travelled on a weekday. The VKT is calculated by multiplying the number of vehicle which based on the highest predicted hourly traffic flow within 15 years upon the commissioning year of the Project, and the length of road travelled in the assessment area. The diurnal variation of VKT in the assessment area is provided by the traffic team, and the input in the model is by vehicle/fuel/hour.

· Speed fraction represents the percentage in different speed ranges of each vehicle type weighted by VKT. The speed limits of existing road have been made reference to the Traffic AIDs (plan marked the road marking, traffic sign and speed limits) from TD, while the speed limits of the proposed road are provided by traffic consultant.

· In accordance with the Road Traffic Ordinance, for any road with design speed limit of 70 kph or above, the maximum speed limit for medium goods vehicles, heavy goods vehicles, buses and buses would be limited to 70 kph. Thus, the speeds of medium goods vehicles, heavy goods vehicles and buses from the flow speed of 70 kph, whichever is lower, are adopted. For the public light buses, the maximum speed limit should be limited to 80 kph. Thus, the speeds of public light buses from the flow speed or 80 kph, whichever is lower, are adopted.

4.10.8 The hourly emissions of NOx, RSP and FSP for the highest emission scenario has been divided by the number of vehicles and the distance travelled to obtain the emission factors in gram per miles per vehicle.

4.10.9 Based on the above parameters, the EMFAC emission burdens for the NCWBR RIW and LTR RIW are listed in Appendix 4.10. The years with the highest emission burden are selected as the worst-case years for operational phase assessment. The selected worst-case years of NOx, RSP and FSP at NCWBR RIW and LTR RIW are summarised as below:

Worst-case years of NCWBR RIW:

· NOx – Year 2020;

· RSP – Year 2026; and

· FSP – Year 2026.

Worst-case years of LTR RIW:

· NOx – Year 2022;

· RSP – Year 2026; and

· FSP – Year 2026.

4.10.10 Details of the Vehicular Emission Factors from EMFAC are listed in Appendix 4.11 and the corresponding Composite Vehicular Emission Factor to CALINE4 Model at the identified worst-case years on NCWBR RIW and LTR RIW are listed in Appendix 4.12.

4.10.11 The United States Environmental Protection Agency (USEPA) approved CALINE4 dispersion model are used to assess traffic emissions impact from existing and planned road network. Surface roughness coefficient of 100 cm has been taken in the CALINE4 model representing the medium-rise and hilly topography in the study area. The grid-specific MM5 meteorological data has been adopted to calculate the hourly impact in accordance with the “TOTAL” Air Quality Guidelines.

4.10.12 For the calculation of NO₂ concentrations, the conversion factor from NOx to NO₂ was based on the Ozone Limiting Method assuming the tailpipe NO₂ emission to be 7.5% of NOx and the background ozone concentration in accordance with the EPD’s Guidelines on Choice of Models and Model Parameters.

Model Assumptions for Secondary Air Quality Impacts

4.10.13 Secondary air quality impacts arising from the implementation of roadside noise barriers and enclosures has been incorporated into the air quality model. Extent of the proposed noise mitigation measures are presented in the Noise Section (Section 5) and are summarised in Table 4.19.

Table 4.19 Proposed Noise Mitigation Measures under RIW Project

Site	Mitigation measures	Remarks
J/O Clear Water Bay Road and On Sau Road	· CT4: about 24m of 7m tall cantilevered noise barrier with 3.5m long cantilever (at 45°) on Clear Water Bay Road · SE2: about 146m of 7m tall semi-enclosure provided on Clear Water Bay Road	See Figure 5.5 on Location under the Noise Chapter
J/O New Clear Water Bay Road and Shun Lee Tsuen Road	· FE1: about 130m of 7m tall full-enclosure provided on New Clear Water Bay Road · CT5: about 45m of 7m tall cantilevered noise barrier with 3.5m long cantilever (at 45°) on New Clear Water Bay Road; · CT6: about 40m of 7m tall cantilevered noise barrier with 3.5m long cantilever (at 45°) on New Clear Water Bay Road.	See Figure 5.6 on Location under the Noise Chapter
Sau Mau Ping Road and Lin Tak Road	· SE1: about 59m of 7m tall semi-enclosure provided on Sau Mau Ping Road · CT1: about 97m of 7m tall cantilevered noise barrier with 3.5m long cantilever (at 45°) on Sau Mau Ping Road · CT2: about 77m of 5.5m tall cantilevered noise barrier with 3.5m long cantilever (at 30°) on Sau Mau Ping Road · CT3: about 91m of 5.5m tall cantilever noise barrier with 3.5m long cantilever (at 45°) on Lin Tak Road flyover · VB1: about 92m of 3m tall vertical noise barrier on Sau Mau Ping Road	See Figure 5.4 on Location under the Noise Chapter

4.10.14 For the proposed vertical noise barriers, cantilevered noise barriers and noise enclosures, it is assumed that dispersion of the traffic pollutants would have effect similar to that traffic pollutants would be emitted from the top of the canopies and semi-enclosures.

4.10.15 Owing to the constraint of the CALINE4 model in modelling elevated roads higher than 10m, the road heights of elevated road sections in excess of 10m high above local ground are set to 10m in the model as the worst-case assumption. For barriers along roads or any proposed noise barriers as a noise mitigation measures, the line source has been modelled at the tip of the barrier and the mixing width is limited to the actual uncovered road width in order to address the associated secondary environmental impact. The road type of the concerned section is set to the “fill” option in CALINE4. Detailed of the emission for each road link are given in Appendix 4.12 for NCWBR RIW and LTR RIW.

4.10.16 Ozone Limiting Method (OLM) has been adopted for conversion of NOx to NO₂, using the predicted O₃ and NO₂ levels from PATH model. According to EPD’s Guidelines on Choice of Models and Model Parameters, the vehicular tailpipe NO₂ emission is assumed to be 7.5% of NOx (combined open road + Secondary Air Quality from barrier/semi-enclosure).

Model Assumptions for Portal Emissions

4.10.17 During the operational phase, portal emission sources within the assessment areas of NCWBR RIW and LTR RIW are identified and have been calculated based on the vehicle emission derived from the adopted emission factors (from EMFAC-HK) and vehicle flows. The identified portal emission sources are listed as below:

NCWBR RIW:

· Proposed full enclosure (i.e. FE1 in Table 4.19) at the J/O New Clear Water Bay Road and Shun Lee Tsuen.

LTR RIW:

· Existing Tseung Kwan O Tunnel (Kowloon Side Exit); and

· Proposed Po Lam Road Underpass.

4.10.18 The Industrial Source Complex Short Term 3 (ISCST3) dispersion model has been used to predict the portal emissions. Portal emissions have been modelled in accordance with the Permanent International Association of Road Congress Report (PIARC, 1991). Pollutants have been 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.

4.10.19 In terms of the assumptions for portal or the percentage split of emission between the tunnel portals are listed in Appendix 4.13 for NCWBR RIW and LTR RIW. Similar to CALINE4, grid-specific composite real meteorological data extracted from EPD’s PATH model has been adopted in ISCST3 model. “Urban” mode has been taken due to the low and medium rise buildings in the study area.

4.10.20 OLM has been adopted for conversion of NOx to NO₂, and the vehicular tailpipe NO₂ emission is assumed to be 7.5% of NOx (combined open road + Secondary Air Quality from barrier + portal + ventilation building).

Model Assumptions for Chimney Emission (Secondary Sources for NCWBR RIW only)

4.10.21 Existing chimneys (restaurants) are located within 500m from the NCWBR RIW. In terms of the emission from these chimneys (see Appendix 4.1), grid-specific composite real meteorological data extracted from EPD’s PATH model have been adopted in ISCST3 model. “Urban” mode is again applied taken into the low and medium rise buildings in the study area.

4.10.22 OLM has been adopted for conversion of NOx to NO₂, and 10% conversion factor to NO₂ emission is assumed. Owing to the fact that emission/discharge points are located at higher elevation, the OLM conversion has been calculated separately from the open road/portal emission.

4.11 Prediction and Evaluation of Environmental Impacts (Operational Phase)

NCWBR RIW

4.11.1 Results indicate that the maximum 1-hour average NO₂, 10th highest daily average RSP and FSP, and annual average NO₂, RSP and FSP concentrations at all representative ASRs would comply with the AQOs. It is predicted that the Project would pose less significant contribution to the cumulative NO₂, RSP and FSP concentration. Detailed results are listed in Appendix 4.14 and the cumulative and project-contributed air pollutant concentration summarised in Table 4.20. The contours at worst hit level (i.e. 1.5m above ground) for NO₂, RSP and FSP are shown in Figures 4.25 – 4.30. There is no ASR identified within the exceedance zone as shown in the contour plots.

Table 4.20 Summary of Assessment Results – NCWBR RIW (Operational Phase)

Pollutant	Averaging Time	AQOs (µg/m³) ⁽¹⁾	Concentration (µg/m³) ⁽²⁾		Compliance to AQO? (Y/N)
Pollutant	Averaging Time	AQOs (µg/m³) ⁽¹⁾	Cumulative ⁽³⁾	Project ⁽⁴⁾	Compliance to AQO? (Y/N)
NO₂	Max. 1-hour	200 (18)	228 - 274 (2 - 7)	<1 - 6	Y
	19^th Highest Hourly	200 (18)	128 - 166	<1 - 18	Y
	Annual	40	18 - 40	<1 - 4	Y
RSP	Max. Daily	100 (9)	107 - 115 (1 - 1)	<1	Y
	10^th Highest Daily	100 (9)	72 - 75	<1	Y
	Annual	50	39 - 41	<1	Y
FSP	Max. Daily	75 (9)	80 - 87 (1 - 1)	<1	Y
	10^th Highest Daily	75 (9)	54 - 56	<1	Y
	Annual	35	28 - 29	<1	Y

Note:

(1) Values in ( ) mean the number of exceedances allowed per year.

(2) Values in ( ) mean the number of exceedance against the AQOs predicted.

(3) Cumulative stands for the predicted cumulative concentration.

(4) Project stands for the predicted concentration contributed by the Project itself.

LTR RIW

4.11.2 Results indicate that the 1-hour average NO₂, 10th highest daily average RSP and FSP, and annual average NO₂, RSP and FSP concentrations at all representative ASRs would comply with the AQOs. It is predicted that the Project would pose insignificant contribution to the cumulative NO₂, RSP and FSP concentration. Detailed results are listed in Appendix 4.15 and the cumulative and project-contributed air pollutant concentration summarised in Table 4.21. The contours at worst hit level (i.e. 1.5m above ground) for NO₂, RSP and FSP are shown in Figures 4.31 – 4.36. There is no ASR identified within the exceedance zone as shown in the contour plots.

Table 4.21 Summary of Assessment Results – LTR RIW (Operational Phase)

Pollutant	Averaging Time	AQOs (µg/m³) ⁽¹⁾	Concentration (µg/m³) ⁽²⁾		Compliance to AQO? (Y/N)
Pollutant	Averaging Time	AQOs (µg/m³) ⁽¹⁾	Cumulative ⁽³⁾	Project ⁽⁴⁾	Compliance to AQO? (Y/N)
NO₂	Max. 1-hour	200 (18)	223 - 263 (5 - 6)	<1 - 2	Y
	19^th Highest Hourly	200 (18)	155 - 181	<1 - 14	Y
	Annual	40	18 - 34	<1 - 1	Y
RSP	Max. Daily	100 (9)	108 – 109 (1 - 1)	<1	Y
	10^th Highest Daily	100 (9)	73 - 75	<1	Y
	Annual	50	39 - 40	<1	Y
FSP	Max. Daily	75 (9)	81 - 82 (1 - 1)	<1	Y
	10^th Highest Daily	75 (9)	55 – 57	<1	Y
	Annual	35	28 - 29	<1	Y

Note:

(1) Values in ( ) mean the number of exceedances allowed per year.

(2) Values in ( ) mean the number of exceedance against the AQOs predicted.

(3) Cumulative stands for the predicted cumulative concentration.

(4) Project stands for the predicted concentration contributed by the Project itself.

4.12 Recommended Mitigation Measures (Operational Phase)

4.12.1 The predicted representative air pollutants including NO₂, RSP and FSP at the worst-case assessment years would comply with AQOs. Hence, no specific mitigation measures would be required during the operational phase of the NCWBR RIW and LTR RIW.

4.13 Evaluation of Residual Environmental Impacts (Operational Phase)

4.13.1 No excessive residual air quality impact is anticipated during the operational phase for NCWBR RIW and LTR RIW.

4.14 EM&A Requirements

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

4.14.2 No adverse impact would be generated during the operation phase of this Project. Therefore, the EM&A works related to air quality for the operational phase is considered not necessary.

4.15 Conclusion

Construction Phase

4.15.1 Potential air quality impacts from the construction works would be mainly due to construction dust from excavation, materials handling and wind erosion. With the implementation of recommended dust suppression measures including watering once per hour on active construction works areas and mitigation measures specified in the Air Pollution Control (Construction Dust) Regulation and EM&A programme, the predicted dust impact on the air sensitive receivers would comply with the dust criteria as stipulated in EIAO-TM and AQO.

Operational Phase

4.15.2 Cumulative air quality impact arising from the vehicular emissions from the open roads, portal emission from TKO tunnel (Kowloon side) and chimney emissions within the assessment area has been assessed at the worst case years. The assessment results conclude that the predicted cumulative 1-hour average and annual average Nitrogen Dioxide, daily average and annual average Respirable Suspended Particulates / Fine Suspended Particulates concentrations at representative ASR would comply with the Air Quality Objectives.

[1] USEPA, AP-42 Compilation of Air Pollution Emission Factors (AP-42), Section 13.2.4.3, 1^st Table

[2]http://www.epd.gov.hk/epd/english/environmentinhk/air/air_maincontent.html

[4] http://www.epd.gov.hk/epd/english/environmentinhk/air/studyrpts/assessment_of_tap_measurements.html

[5]http://www.eea.europa.eu/publications/EMEPCORINAIR5/Sources_of_PCB_emissions.pdf/view

[6] http://www.epd.gov.hk/epd/english/news_events/legco/files/EA_Panel_110526a_eng.pdf

[7]http://www.epd.gov.hk/epd/english/environmentinhk/air/prob_solutions/cleaning_air_atroad.html

[8] http://www.epd.gov.hk/epd/english/environmentinhk/air/studyrpts/files/HKEPDFinalReportRev_11-29-10_v2.pdf

[9] Assessment of Toxic Air Pollutant Measurements in Hong Kong Final Report

[10]http://ec.europa.eu/environment/air/quality/standards.htm

[11] http://www.medway.gov.uk/environmentandplanning/environmentalhealth/airquality/airqualityfordevelopers.aspx

Pollutant	Averaging Time	Maximum Average Concentration (µg/m³) ⁽¹⁾	No. of Exceedances Allowed ⁽²⁾
Fine Suspended Particulates (PM 2.5) ⁽⁴⁾	24-hr	75	9
Fine Suspended Particulates (PM 2.5) ⁽⁴⁾	Annual ⁽³⁾	35	NA
Respirable Suspended Particulates (PM10) ⁽⁵⁾	24-hr	100	9
Respirable Suspended Particulates (PM10) ⁽⁵⁾	Annual ⁽³⁾	50	NA
Sulphur Dioxide (SO₂)	10-min	500	3
Sulphur Dioxide (SO₂)	24-hr	125	3
Nitrogen Dioxide (NO₂)	1-hr	200	18
Nitrogen Dioxide (NO₂)	Annual ⁽³⁾	40	NA
Carbon Monoxide (CO)	1-hr	30,000	0
Carbon Monoxide (CO)	8-hr	10,000	0
Photochemical Oxidants (as ozone)	8-hr	160	9
Lead (Pb)	Annual ⁽³⁾	0.5	NA

Pollutant	Averaging Time	AQO^[1]	Year	Year ^[2] ^[5]					5-year mean ^[3]
				2010	2011	2012	2013	2014
Fine Suspended Particulates (PM _2.5)	24-hr	75 (9)	Max.	N/M	83	78	122	98	-
			10th Max.	N/M	64	63	87	68	-
			No. of Exceedance(s)	-	3	2	19	7	-
	Annual	35	-	N/M	31	28	33	31	-
Respirable Suspended Particulates (PM₁₀)	24-hr	100 (9)	Max.	681^[4]	117	169	171	140	149 ^[8]
			10th Max.	97	97	95	123	110	104
			No. of Exceedance(s)	9	6	6	29	13	-
	Annual	50	-	47	49	43	52	51	48
Sulphur Dioxide (SO₂) ^[6]	10-min	500 (3)	Max.	N/M	N/M	N/M	N/M	147 ^[7]	-
			4th Max.	N/M	N/M	N/M	N/M	125 ^[7]	-
	24-hr	125 (3)	Max.	34	42	53	54	65	50
			4th Max.	29	31	37	35	38	34
			No. of Exceedance(s)	-	-	-	-	-	-
Nitrogen Dioxide (NO₂)	1-hr	200 (18)	Max	242	285	398	339	329	319
			19th Max.	190	241	260	226	217	227
			No. of Exceedance(s)	9	41	78	49	28	-
	Annual	40	-	59	63	59	59	54	59
Carbon Monoxide (CO)	1-hr	30,000	-	N/M	N/M	N/M	N/M	N/M	-
	8-hr	10,000	-	N/M	N/M	N/M	N/M	N/M	-
Ozone (O₃)	8-hr	160 (9)	Max.	132	146	155	182	207	164
			10th Max.	100	113	120	127	133	119
			No. of Exceedance(s)	-	-	-	1	2	-
Note: [1] Values in ( ) mean the number of exceedances allowed per year.
[2] Bolded values mean exceedance of the AQOs.
[3] The 5-year mean is the arithmetic average.
[4] The value was recorded during a dust plume originated from northern part of China in March 2010 which was an abnormal event.
[5] N/M – Not Measured.
[6] Monitoring data for the AQO of 10-minute SO₂ on or before Year 2013 is currently not publicly available. [7] Extracted from EPD’s Air Quality in Hong Kong 2014, Statistical Summary, http://www.aqhi.gov.hk/api_history/english/report/files/AQR2014%20summary_en.pdf [8] The mean for 2011-2014 and the exceptional high record aue to an abnormal event in 2010 is not included.

	Pollutant	Averaging Time	AQO^[1]		PATH Grid Cell ^[2] ^[3]
					(32,29) Near J/O New Clear Water Bay Road and Shun Lee Tsuen Road		(33,28) Near J/O Sau Mau Ping Road/ Lin Tak Road RIW		(33,29) Near J/O Clear Water Bay Road /On Sau Road
				Year	2015	2020	2015	2020	2015	2020
	Fine Suspended Particulates (PM 2.5) ^[4]	24-hr	75 (9)	Max.	83	80	84	81	89	85
				10th Max.	56	54	57	55	58	56
				No. of Exceedance(s)	1	1	1	1	1	1
		Annual	35	-	29	28	28	28	29	29
	Respirable Suspended Particulates (PM10)	24-hr	100 (9)	Max.	111	107	112	108	118	114
				10th Max.	75	72	75	74	77	75
				No. of Exceedance(s)	1	1	1	1	1	1
		Annual	50	-	41	40	40	39	41	40
	Sulphur Dioxide (SO₂)	10-min	500 (3)	Max.	N/A	N/A	N/A	N/A	N/A	N/A
		10-min	500 (3)	4th Max.	N/A	N/A	N/A	N/A	N/A	N/A
		24-hr	125 (3)	Max.	24	25	25	26	24	24
				4th Max.	20	21	20	22	20	20
				No. of Exceedance(s)	-	-	-	-	-	-
	Nitrogen Dioxide (NO₂)	1-hr	200 (18)	Max	265	229	278	257	278	251
				19th Max.	157	137	184	160	153	136
				No. of Exceedance(s)	7	2	11	5	7	3
		Annual	40	-	23	19	25	20	22	18
	Carbon Monoxide (CO)	1-hr	30,000	-	1,309	1,302	1,403	1,320	1,306	1,296
	Carbon Monoxide (CO)	8-hr	10,000	-	947	918	1,106	1,032	940	904
	Photochemical Oxidants (as ozone)	8-hr	160 (9)	Max.	161	161	158	161	167	166
				10th Max.	119	118	111	117	116	119
				No. of Exceedance(s)	1	1	-	1	1	1
Note: [1] Values in ( ) mean the number of exceedances allowed per year.
[2] Bolded values mean exceedance of the AQOs. [3] N/A – Not Available.

4.1 Environmental Legislation, Plans, Standards, and Guidelines

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

4.1.2 The prevailing AQO, as tabulated in Table 4.1 has been in forced since 1 January 2014.

4.1.3 The Annex 4 of EIAO-TM stipulates that hourly Total Suspended Particulate (TSP) level should not exceed 500µg/m3 measured at 298K and 101.325kPa (one atmosphere) for the construction dust impact assessment.

4.1.4 Guidelines for conducting air quality assessment are stipulated in Annex 12 of EIAO-TM, including the determination of air sensitive receivers (ASRs), the assessment methodology, baseline study and impact prediction and assessment.

4.1.7 There are some guidelines which detail the overall air quality assessment approaches:

4.2 Description of the Environment and Future Trends

4.2.2 In terms of the Lin Tak Road Modification section, the major air pollution source in the vicinity is originated from road emission from Tsueng Kwan O Road, Lin Tak Road, Lei Yue Mun Road, and Kai Tin road.

4.2.3 The baseline conditions for air quality impact assessment has been updated based on the 2010 - 2014 average monitoring data recorded at Kwun Tong Air Quality Monitoring Station (AQMS). The observations are summarized in Table 4.2.

4.2.7 In terms of FSP, EPD has recently commenced the regular monitoring since 2012, and thus, there is in-sufficient data to establish the 5-year averaged result.

4.3 Study Area and Air Sensitive Receivers

4.3.2 The study areas contain a mixture of existing residential buildings, future residential buildings, schools and commercial premises. Air sensitive receivers (ASRs) located in the vicinity of the 500m from the works boundary have been reviewed.

4.3.3 Planned/committed ASRs have been reviewed and updated by making reference to the latest Outline Zoning Plans (OZP), Layout Plans and other published plans in vicinity of the development, including:

4.3.4 Representative ASRs in the vicinity of the three sites are selected for the assessment. Details of the representative ASRs for NCWBR RIW and LTR RIW are presented in the below Table 4.4 and Table 4.5, respectively and their locations are shown in Figure 4.1 and Figure 4.2.

4.3.6 Air contours within the 500m assessment areas are prepared for the worst-hit level.

4.4.1 The construction activities for the Project would be commenced in late 2016 and completed in early 2022 and the construction period would be around 60 months. The major construction activities are summarized as below:

4.4.2 During this construction period, the following concurrent projects with construction works in the vicinity of the three RIW sites have been reviewed in terms of cumulative impacts and the assumptions on concurrent works are listed as follows:

4.4.4 The tunnel portal of the Tseung Kwan O Tunnel on the Kowloon side is located within the 500m assessment area of the LTR RIW. Details of the locations and the emission inventory are shown in Appendix 4.2.

4.5.1 Dust emission impact is predicted based on emission factors from USEPA Compilation of Air Pollution Emission Factors (AP-42), 5th Edition. The major dusty construction activities for the Project to be concerned and considered in the modelling assessment include:

4.5.6 The dust emission factors of the above construction activities for the Project are summarized in Table 4.7 below.

4.5.8 The hourly meteorological data including wind speed, wind direction, and air temperature from the relevant grids from the MM5 Meteorological data (same basis for PATH model), are employed for the model run. The Pasquill stability class data are modelled separately using PC-Ramet model.

4.5.10 A Fugitive Dust Model (FDM) is used to assess the potential dust impact from construction activities. A height of 1.5m (the breathing level of human), 5m and 10m above ground would be adopted for the construction dust impact assessment. Air contour is prepared for the worst-hit level.

4.5.18 Based on the initial estimation, it is identified that Year 2017 is the worst-case year for NCWBR RIW and Year 2018 for LTR RIW on evaluation of construction dust cumulative impacts. The cumulative sources are listed in Table 4.10. Details of dust emission sources are shown in Appendix 4.5.

4.6 Prediction and Evaluation of Environmental Impacts (Construction Phase)

4.6.3 The contour plots for 1-hour average TSP, 10th highest daily average RSP and FSP and annual average RSP and FSP at the worst hit level, 1.5m above ground, under unmitigated and mitigated scenarios are shown in Figures 4.3 – 4.12.

4.6.5 In order to alleviate the potential dust impacts, hourly watering is considered to be applied for the active construction area with an assumption of dust removal efficiency of 87.5% (see Appendix 4.6).

4.6.7 The contour plots for maximum 1-hour average TSP, 10th highest daily average RSP and FSP and annual average RSP and FSP at the worst hit level, 1.5m above ground, under unmitigated and mitigated scenarios are shown in Figures 4.13 – 4.22.

4.7.1 As mentioned in Section 4.6, the watering frequency is assumed to be once per hour and the watering application intensity is estimated to be 0.0455 L/m2 so as to achieve a dust removal efficiency of 87.5%.

4.7.2 The following standard dust suppression measures will be suggested. They should be incorporated by the Contractor as a General Specification to control the dust nuisance throughout the construction phase:

4.8.1 No excessive residual impact is anticipated for the Project during construction phase.

4.9 Identification of Environmental Impacts (Operational Phase)

4.9.9 In view that road transport only contributes a very small amount of SO2 emission, relatively low measured concentrations and the adoption of low-sulphur and ultra-low-sulphur fuel under the existing government policy, SO2 would not be a critical air pollutant of concern.

4.9.14 Diesel Particulate Matters (DPM), as part of the overall Respirable Suspended Particulates (RSP), is one of the most important parameter contributing to the overall health risk of the population. Local vehicular emission is one of the major sources of DPM.

4.10 Assessment Methodology (Operational Phase)

4.10.3 In accordance with EPD’s “Guidelines on Assessing the 'TOTAL' Air Quality Impacts (revised version on Mar 2013)”, emission sources could be classified into 3 categories as follows, depending on their distance from the concerned site:

4.10.5 The following approach has been adopted for the operational phase cumulative air quality impact assessment:

4.10.6 NCWBR RIW and LTR RIW will be commissioning at Year 2020 and Year 2022, respectively. In terms of cumulative impacts, the following projects have been reviewed whether it is considered in the assessment.

4.10.8 The hourly emissions of NOx, RSP and FSP for the highest emission scenario has been divided by the number of vehicles and the distance travelled to obtain the emission factors in gram per miles per vehicle.

4.10.10 Details of the Vehicular Emission Factors from EMFAC are listed in Appendix 4.11 and the corresponding Composite Vehicular Emission Factor to CALINE4 Model at the identified worst-case years on NCWBR RIW and LTR RIW are listed in Appendix 4.12.

4.10.13 Secondary air quality impacts arising from the implementation of roadside noise barriers and enclosures has been incorporated into the air quality model. Extent of the proposed noise mitigation measures are presented in the Noise Section (Section 5) and are summarised in Table 4.19.

Sau Mau Ping Road and Lin Tak Road

4.10.14 For the proposed vertical noise barriers, cantilevered noise barriers and noise enclosures, it is assumed that dispersion of the traffic pollutants would have effect similar to that traffic pollutants would be emitted from the top of the canopies and semi-enclosures.

4.10.20 OLM has been adopted for conversion of NOx to NO2, and the vehicular tailpipe NO2 emission is assumed to be 7.5% of NOx (combined open road + Secondary Air Quality from barrier + portal + ventilation building).

4.10.22 OLM has been adopted for conversion of NOx to NO2, and 10% conversion factor to NO2 emission is assumed. Owing to the fact that emission/discharge points are located at higher elevation, the OLM conversion has been calculated separately from the open road/portal emission.

4.12 Recommended Mitigation Measures (Operational Phase)

4.12.1 The predicted representative air pollutants including NO2, RSP and FSP at the worst-case assessment years would comply with AQOs. Hence, no specific mitigation measures would be required during the operational phase of the NCWBR RIW and LTR RIW.

4.13 Evaluation of Residual Environmental Impacts (Operational Phase)

4.13.1 No excessive residual air quality impact is anticipated during the operational phase for NCWBR RIW and LTR RIW.

4.14.2 No adverse impact would be generated during the operation phase of this Project. Therefore, the EM&A works related to air quality for the operational phase is considered not necessary.

4.1.2 The prevailing AQO, as tabulated in Table 4.1 has been in forced since 1 January 2014 .

4.1.3 The Annex 4 of EIAO-TM stipulates that hourly Total Suspended Particulate (TSP) level should not exceed 500µg/m³ measured at 298K and 101.325kPa (one atmosphere) for the construction dust impact assessment.

4.7.1 As mentioned in Section 4.6, the watering frequency is assumed to be once per hour and the watering application intensity is estimated to be 0.0455 L/m² so as to achieve a dust removal efficiency of 87.5%.

4.9.9 In view that road transport only contributes a very small amount of SO₂ emission, relatively low measured concentrations and the adoption of low-sulphur and ultra-low-sulphur fuel under the existing government policy, SO₂ would not be a critical air pollutant of concern.

4.10.20 OLM has been adopted for conversion of NOx to NO₂, and the vehicular tailpipe NO₂ emission is assumed to be 7.5% of NOx (combined open road + Secondary Air Quality from barrier + portal + ventilation building).

4.10.22 OLM has been adopted for conversion of NOx to NO₂, and 10% conversion factor to NO₂ emission is assumed. Owing to the fact that emission/discharge points are located at higher elevation, the OLM conversion has been calculated separately from the open road/portal emission.

4.12.1 The predicted representative air pollutants including NO₂, RSP and FSP at the worst-case assessment years would comply with AQOs. Hence, no specific mitigation measures would be required during the operational phase of the NCWBR RIW and LTR RIW.