Table of Contents

3 Air Quality Impact. 3-1

3.1 Introduction. 3-1

3.2 Environmental Guidelines, Standards and Criteria. 3-1

3.3 Description of the Environment. 3-2

3.4 Identification of Potential Impacts. 3-6

3.5 Assessment Methodology. 3-11

3.6 Prediction and Evaluation of Environmental Impacts. 3-19

3.7 Mitigation of Adverse Environmental Impacts. 3-26

3.8 Evaluation of Residual Impacts. 3-28

3.9 Environmental Monitoring and Audit. 3-28

3.10 Conclusion. 3-28

List of Tables

Table 3.1 Hong Kong Air Quality Objectives.. 3-1

Table 3.2 Summary of the Latest Available Five-Year Air Quality Data at Kwun Tong Station (Year 2013 to Year 2017) 3-3

Table 3.3 Air Pollutants Concentrations at the Project Site in 2020 Predicted from PATH-2016 Model 3-4

Table 3.4 Representative Air Sensitive Receivers.. 3-5

Table 3.5 Parameters for Sediment Odour Potential Test.. 3-11

Table 3.6 Adopted Parameters of Marine Vessel. 3-15

Table 3.7 Operation Mode Definition by Vessel Speed.. 3-16

Table 3.8 Worst Predicted Cumulative Daily RSP Concentration during Operation Phase.. 3-21

Table 3.9 Worst Predicted Cumulative Annual RSP Concentration during Operation Phase.. 3-21

Table 3.10 Worst Predicted Cumulative Daily FSP Concentration during Operation Phase.. 3-22

Table 3.11 Worst Predicted Cumulative Annual FSP Concentration during Operation Phase.. 3-22

Table 3.12 Worst Predicted Cumulative Hourly NO2 Concentration during Operation Phase.. 3-23

Table 3.13 Worst Predicted Cumulative Annual NO2 Concentration during Operation Phase.. 3-24

Table 3.14 Worst Predicted Cumulative 10-min SO2 Concentration during Operation Phase.. 3-24

Table 3.15 Worst Predicted Cumulative Daily SO2 Concentration during Operation Phase.. 3-25

Figures

Figure 3.1 Locations of Representation Air Sensitive Receivers

Appendices

Appendix 3.1 Not Used

Appendix 3.2 Final Odour Patrol Report

Appendix 3.3 Traffic Data

Appendix 3.4 Calculation of Vehicular Emission Source

Appendix 3.5 Calculation of Marine Emission Source

Appendix 3.6 Emission Sources of Nearby Industrial Process

Appendix 3.7 Determination of Surface Characteristics Parameters

Appendix 3.8 Detail Prediction of Air Quality Impact during Operation Phase

Appendix 3.9 Results of Sediment Odour Potential Test

3 Air Quality Impact

3.1 Introduction

3.1.1.1 This section presents an air quality impact assessment for the construction and operational phases of the Lei Yue Mun Waterfront Enhancement Project. The assessment was conducted in accordance with the requirements in Annexes 4 and 12 of the Technical Memorandum on Environmental Impact Assessment Ordinance (EIAO-TM) and the requirements in Section 3.4.3 and Appendix A of the EIA Study Brief.

3.2 Environmental Guidelines, Standards and Criteria

3.2.1.1 The relevant legislation, standards and guidelines applicable to the assessment of air quality impacts in this study are:

• Air Pollution Control (Amendment) Ordinance 2013 (APCO) (Cap 311) - this provides the power for controlling air pollutants from a variety of stationary and mobile sources and encompasses a number of Air Quality Objectives (AQOs);

• Environmental Impact Assessment Ordinance (EIAO) (Cap 499), Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM), Annex 4 and Annex 12;

• Air Pollution Control (Construction Dust) Regulation (Cap 311R); and

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

3.2.2 Air Pollution Control Ordinance (APCO)

3.2.2.1 The prevailing AQO, as tabulated in Table 3.1 below has been in forced since 1 January 2014.

Table 3.1 Hong Kong Air Quality Objectives

Pollutant	Averaging Time	Concentration Limit, µg/m³ ^(1)	No. of Exceedances Allowed per Year
Fine Suspended Particulates (PM2.5 / FSP)^(3)	24-hour	75	9
	Annual^(2)	35	Not applicable
Respirable Suspended Particulates (PM10 / RSP)^(4)	24-hour	100	9
	Annual^(2)	50	Not applicable
Sulphur Dioxide (SO₂)	10-minute	500	3
	24-hour	125	3
Nitrogen Dioxide ( NO₂)	1-hour	200	18
	Annual^(2)	40	Not applicable
Photochemical Oxidants (as Ozone)	8-hour	160	9
Carbon Monoxide (CO)	1-hour	30,000	0
	8-hour	10,000	0
Lead (Pb)	Annual^(2)	0.5	Not applicable

Notes:

(1) Measured at 293 K and 101.325 kPa.

(2) Arithmetic mean.

(3) Suspended particulates in air with a nominal aerodynamic diameter of 2.5 µm or less.

(4) Suspended particulates in air with a nominal aerodynamic diameter of 10 µm or less.

3.2.3 EIAO-TM

3.2.3.1 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.

3.2.3.2 For odour prediction assessment, odour level at an air sensitive receiver should meet 5 odour units based on an averaging time of 5 seconds.

3.2.4 Air Pollution Control (Construction Dust) Regulation

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

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

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

3.3 Description of the Environment

3.3.1 Baseline Condition

3.3.1.1 The Project site is located at the south-eastern part of Kowloon Peninsula. It is at the seafront of Lei Yue Mun which is a developed area with mainly village houses and seafood restaurants. Site surveys were conducted in November 2016, early March 2017, mid October 2017 and early January 2018. Three concrete batching plants at Tung Yuen Street located about 450m-500m from the north-west of the Project site boundary were found. Two of these plants have applied the Specified Process (SP) Licence for its operation under APCO, the dust level arising from these concrete batching plants at its nearest air sensitive receivers would comply with AQO. Within the 500m study area, except six chimneys for restaurants found in Sam Ka Tsuen, no further industrial chimneys were identified though a few industrial buildings are located at Sze Shan Street. The existing dominant sources of air pollutants in this area include road traffic emissions from existing roads at Yau Tong area and marine traffic emissions from ferries travelling to/from Sam Ka Tsuen Ferry Pier which is at least 200m from the northwest of the Project works area.

3.3.1.2 The EPD air quality monitoring station closest to the Project site is Kwun Tong Station. The latest available five-year air quality data measured at Kwun Tong Station are summarised in Table 3.2.

Table 3.2 Summary of the Latest Available Five-Year Air Quality Data at Kwun Tong Station (Year 2013 to Year 2017)

Air Pollutant	Averaging Time		Concentration, μg/m³					AQO, μg/m³
			Year 2013	Year 2014	Year 2015	Year 2016	Year 2017
FSP	24-hour	10^th Highest	87	68	65	50	53	75
	Annual		33	31	27	23	23	35
RSP	24-hour	10^th Highest	123	110	99	89	84	100
	Annual		52	51	44	37	39	50
SO₂	10-min	4^th Highest	N.A.	125	79	53	53	500
	24-hour	4^th Highest	35	38	22	17	19	125
NO₂	1-hour	19^th Highest	226	217	271	200	199	200
	Annual		59	54	55	54	44	40
O₃	8-hour	10^th Highest	127	133	130	116	135	160
CO	1-hour	1^stHighest	N.A.	N.A.	N.A.	N.A.	N.A.	30,000
	8-hour	1^stHighest	N.A.	N.A.	N.A.	N.A.	N.A.	10,000

Notes:

N.A – not applicable

(1) No monitoring data is available for 10-minute average levels of SO₂ in Year 2013, and CO levels from Year 2013 to 2017.

(2) Monitoring results exceeding AQOs are shown as bold and underlined characters.

(3) All data was calculated from the hourly data provided in EPD’s website (http://epic.epd.gov.hk/EPICDI/air/station/?lang=en) and extracted from EPD’s Air Quality Reports – Annual Air Quality Monitoring Results (http://www.aqhi.gov.hk/en/download/air-quality-reportse469.html?showall=&start=1).

(4) Reference conditions of gaseous pollutants concentration data: 298K and 101.325 kPa.

3.3.1.3 As shown in Table 3.2, the tenth highest daily FSP in Year 2013, the tenth highest daily RSP and annual average RSP in Year 2013 and 2014, and the nineteenth highest hourly NO₂ from Year 2013 to 2016 and annual average NO₂ from Year 2013 to 2017 exceeded the AQO criteria. For other pollutants, the measured concentrations at Kwun Tong Station during Year 2013 to 2017 complied with the AQO criteria. However, the ambient air quality in Project area may differ from the one at Kwun Tong Station. Kwun Tong Station locates in urban area with mixed uses and busy road traffic nearby. The Project area in Lei Yue Mun locates more than 3km away from Kwun Tong Station, which is a developed area with mainly village houses and seafood restaurants with the closest major road, Shung Shun Street, at least 200m away. Therefore, better ambient air quality is expected in Project area.

3.3.1.4 The construction of the Project will commence in Q3 2019 and complete in Q1 2023. The operation of the Project will commence in Q1 2023. As a general reference, the future prevailing background concentrations can be made reference to the EPD’s Pollutants in the Atmosphere and the Transport over Hong Kong-2016 (PATH-2016) modelling results for Year 2020. The PATH model is a regional air quality model developed by EPD to simulate air quality over Hong Kong against the Pearl River Delta (PRD) as background. PATH is set up on a three-dimensional grid system with horizontal nesting. The PATH results for the Project site in 2020 are summarized in Table 3.3.

Table 3.3 Air Pollutants Concentrations at the Project Site in 2020 Predicted from PATH-2016 Model

Air Pollutant	Averaging Time		Predicted Background Concentration in Year 2020, μg/m³	AQO, μg/m^3
FSP	24-hour	10^th Highest	55	75
	Annual		23	35
RSP	24-hour	10^th Highest	73	100
	Annual		32	50
SO₂	10-min	4^th Highest	110 - 118	500
	24-hour	4^th Highest	21 - 24	125
NO₂	1-hour	19^th Highest	105 - 110	200
	Annual		13 - 14	40
O₃	8-hour	10^th Highest	151 - 153	160
CO	1-hour	1^st Highest	1008 - 1010	30,000
	8-hour	1^st Highest	828 - 831	10,000

Notes:

(1) Extracted from PATH grids (46, 30) and (47, 30) in which the Project site is located.

(2) Predicted concentrations exceeding AQOs are shown as bold and underlined characters.

(3) With reference to the EPD’s Guidelines on Choice of Models and Model Parameters, PATH-2016’s output of RSP concentration is adjusted as follows:

- 10^th highest daily RSP concentration: add 26.5 µg/m³

- Annual RSP concentration: add 15.6 µg/m³

(4) With reference to EPD’s Guidelines on the Estimation of PM2.5 for Air Quality Assessment in Hong Kong, the following conservative formulae are adopted to calculate background FSP concentration from the RSP concentration extracted from the PATH model:

- Annual (µg/m³): FSP = 0.71 × RSP

- Daily (µg/m³): FSP = 0.75 × RSP

3.3.1.5 As shown in Table 3.3, the predicted background concentrations of all concerned air pollutants would be well within their respective AQOs upon the commencement of the operation of the Project.

3.3.1.6 In addition to the site surveys for identification of chimneys within the study area, odour surveys were also conducted to identify any potential existing odour sources in the Project area (in the vicinity of the proposed air sensitive uses). A two-day odour patrol in Project area was conducted by a qualified odour panel, which all panel members’ individual n-butanol thresholds are in the range of 20 to 80 ppb/v as required by the European Standard Method for Olfactometry (EN13725), in November 2016 to identify any potential odour sources at LYM waterfront and record any odour intensity at the 12 odour spot-check points along LYM waterfront. Most of these spot-check points are the air sensitive uses such as viewing platform and lookout points. On-site H₂S was measured using Jerome J605 Hydrogen Sulphide Analyser in conjunction to the odour patrol. The details of the odour patrol and H₂S measurement are presented in the Final Odour Patrol Report in Appendix 3.2.

3.3.1.7 The outcome of the odour surveys shows that there are no odour sources causing nuisance found in the vicinity of the planned ASRs and along LYM waterfront. The findings of the H₂S measurement revealed that the H₂S concentrations at all spot-check points were all lower than the detection limit. The maximum odour intensity at all spot-check points was ranged from 0 – 1 (under the scale of 0 to 4, which “0” represents no odour perceived and “4” represents severe odour). The detected odour at some spot-check points was from seawater with the odour nature of fishy smell and the duration was intermittent, it is not considered as odour nuisance. No any other odour sources were found in the study area.

3.3.2 Representative Air Sensitive Receivers

3.3.2.1 According to the EIA Study Brief, the study area for the air quality impact assessment is defined by a distance of 500 metres from the boundary of the Project site as shown in Figure 3.1. Existing, planned and committed representative air sensitive receivers (ASRs) are identified based on the relevant Outline Zoning Plans, Development Permission Area Plans, Outline Development Plans and Layout Plans and other relevant published land use plans. The identified representative ASRs within the Study Area of the Project are described in Table 3.4 and their locations are shown in Figure 3.1.

Table 3.4 Representative Air Sensitive Receivers

ASR	Description		Land Use		Approximate Horizontal Distance from the Nearest Site Boundary (m)	No. of Storey
Existing ASRs
A1	Former Hoi Bun School Basketball Court			Recreational	<1	0
A2	Jockey Club Lei Yue Mun Plus			Performing Arts Centre & Educational Institution	1.1	2
A3	Existing Lookout Point 1			Recreational	0	0
A4	No. 53A Lei Yue Mun Hoi Pong Road Central			Commercial & Residential*	<1	2
A5	Existing Lookout Point 2			Recreational	0	0
A6	Existing Viewing Platform			Recreational	0	0
A7	Playground			Recreational	<1	0
A8	Lei Yue Mun Rest Garden			Recreational	<1	0
A9	Lei Yue Mun Basketball Court			Recreational	1.3	0
A10	No. 20A Ma Wan Tsuen			Residential	<1	2
A11	No. 73A Lei Yue Mun Hoi Pong Road East			Residential	<1	2
A12	No. 75B Ma Wan Tsuen			Residential	1.4	2
A13	Existing Lookout Point 3			Recreational	0	0
A14	Existing Lookout Point 4			Recreational	0	0
A15	Existing Lookout Point 5			Recreational	0	0
A16	No. 83 Ma Pui Tsuen			Residential	24.6	2
A17	Tin Hau Temple			Place of Worship	21.7	1
Planned ASRs
P1	Proposed Pavilion	Recreational			0	0
P2	Proposed Carp-Shaped Platform	Recreational			0	0
P3	Proposed Promenade (Landing Facility)	Recreational			0	0

Remarks:

* including restaurants and shops

3.4 Identification of Potential Impacts

3.4.1 Construction Phase

Potential Fugitive Dust Emission from the Project Work Sites

3.4.1.1 The Project would include the following construction works and the details of construction activities for the above-mentioned construction works have been presented in Section 2 and Table 2.1.

• Construction of a landing facility and a breakwater;

• Structural improvement works for existing lookout points (No. 1, 3, 4 and 5) and the viewing platform;

• Construction of a carp-shaped platform and a pavilion with children play area;

• Beautification works for the promenade, five lookout points and an existing viewing platform; and

• Streetscape improvement works.

3.4.1.2 The construction of the landing facility and breakwater would involve dredging, construction of piles and pile caps, construction of deck structures including beams and slabs construction as well as panel walls installation, and reinstating the existing sloping seawall, potential dust emission from these construction activities would not be anticipated.

3.4.1.3 Regarding the structural improvement works for the four existing lookout points and viewing platform, it would involve demolishing of existing structures, excavation, concreting works and backfilling works. Potential dust emissions would be arising from demolition activities, excavation and backfilling works, as well as wind erosion of excavated areas. However, the dust impact would be limited as these improvement works would be conducted in two phases. After completion of the works for lookout points No. 1 and 3, the works for lookout points No. 4 and 5 would then commence.

3.4.1.4 Activities for construction of a carp-shaped platform would include the steel reinforcement works and concreting works adjacent to the viewing platform. The provision of a pavilion at the children play area would involve shallow piling foundation works, steel reinforcement works and concreting works. These construction activities are not considered as dusty activities, significant dust emission from these works is not anticipated.

3.4.1.5 Beautification works would comprise of provision of planter curb and wall, decorative mosaic tiles, light fittings installation, and vertical green wall construction, will be carried out at promenade, lookout points, viewing platform and streetscape area. Improvement works, including protective barriers, proprietary sitting bench and litter bins installation, will be constructed at designated locations. Areas beyond the non-renovation areas will be protected and remain unchanged, for example, the existing pavement would be kept except the provision of the decorative mosaic tiles. These construction works would involve in minor excavation works only, with the limited scale of work areas, the beautification works and streetscape improvement would not generate adverse dust impact.

3.4.1.6 As presented in Section 2.11, there is a concurrent project, Lei Yue Mun Village Sewerage project by DSD, in the vicinity of the Project. Cumulative dust impact may be anticipated from this concurrent project, during the improvement works for existing lookout points and viewing platform from Q3 2019 to Q4 2020.

Odour from Capital Dredging

3.4.1.7 According to the tentative construction programme (Appendix 2.1), removal of sediments to -3.646 mPD by the mean of dredging in the vicinity of the proposed public landing facility, as indicated in Figure 3.1, would be conducted during Q2 2020 to Q4 2020 for about 7 months. Approximately 10,875 m³ soil and 1,750 m³ underwater rock are required to be dredged and removed in order to provide sufficient water depth for vessels using the proposed landing facility.

3.4.1.8 Marine sediments may contain high levels of acid-volatile sulphide (AVS) which releases hydrogen sulphide (H₂S) gas to the overlying water and atmosphere under highly negative redox conditions. H₂S is a colourless gas with the characteristic foul odour of rotten eggs. The key factors that affect this type of odour generation are:

• Overlying water depths, influenced by tidal effects;

• Water quality, in particular dissolved oxygen concentration and stratification effect;

• Temperature;

• Sediment quality including total organic content (TOC), redox potential and AVS levels; and

• Water circulation which influence the water quality and rate of sediment deposition in the water system.

3.4.1.9 Odour may therefore arise from the sediments during the dredging activities, and temporary storage and transportation of the sediments if the sediments’ AVS content is high, and without proper management.

3.4.2 Operation Phase

Existing Open Road Emission

3.4.2.1 Sze Shan Street, Shung Shun Street, and Tung Yuen Street are the roads within the 500m study area of the Project. According to The Annual Traffic Census 2015 issued by Transport Department (TD), the three roads are all categorised as local distributors. These open roads also contribute to the cumulative air quality of the study area. NO₂, RSP and FSP are the major air pollutants associated with vehicular emission.

Existing and Induced Marine Traffic Emission

3.4.2.2 There is no routine schedule designed for the proposed public landing facility. Based on the estimation from Marine Traffic Engineer, assuming 100% utilization rate of the landing facility within an hour to represent the worst-case scenario, the estimated peak hour vessel trip (2-way) including the local tour group vessel and other pleasure vessels (diverted from Sam Ka Tsuen Landing Steps) as well as miscellaneous local vessels would be around 30 vessel trips per hour. Therefore, the potential marine emission from the proposed public landing facility is anticipated and it contributes to the cumulative air quality impacts on the nearby ASRs during the operational phase of the Project. NO₂, SO₂, RSP and FSP are the major air pollutants associated with marine emission.

3.4.2.3 Apart from induced marine traffic to the proposed public landing facility, there are also existing marine routes located within the 500m study area of the Project, including Eastern Fairway, routes approaching / departing Sam Ka Tsuen Ferry Pier and Sam Ka Tsuen Landing Steps. Various kinds of marine vessels such as pleasure vessel, fishing vessel and ocean-going vessels are entering or leaving Victoria Harbour via the Eastern Fairway. Existing ferry routes area is also identified between Sam Ka Tsuen to Sai Wan Ho and Tung Lung Chau. Sam Ka Tsuen Landing Steps also provides public landing for Yau Tong and Lei Yue Mun areas. All these existing marine traffic also contributes to the ambient air quality of the study area.

Identification of Key Air Pollutants of Marine Emission in Operation Phase

3.4.2.4 The Project induces marine emission from the vessels accessing the proposed new landing facility. Marine emission comprises a number of pollutants, including Nitrogen Oxides (NO_X), RSP, FSP, Sulphur Dioxides (SO₂), Carbon Monoxide (CO), Volatile Organic Compound (VOC), etc. However, NO₂, RSP, FSP and SO2 are considered as the key air pollutants in the quantitative assessment for the Project.

3.4.2.5 Nitrogen Oxides (NO_X) is a major pollutant from fossil fuel combustion. According to the 2015 Hong Kong Emission Inventory Report published by EPD, marine vessel was the largest NO_X emission source and accounted for 37% of the total emission in Year 2015. Vehicle was also a major NO_X emission source which accounted for 18% of the total. In the presence of O₃ and VOC, NO_X would be converted to NO2. Induced marine traffic would inevitably increase the NO_X emission and subsequent onshore NO₂ concentration near the new landing facility. NO₂ is therefore one of the key air pollutants for the Project. NO_X emission due to fuel combustion at restaurants are also considered in the assessment.

3.4.2.6 Respirable Suspended Particulates (RSP) refers to suspended particulates with a nominal aerodynamic diameter of 10µm or less. According to the 2015 Hong Kong Emission Inventory Report published by EPD, marine vessel is the largest RSP emission source and accounted for 34% of the total emission in Year 2015.Vehicle was also a RSP emission source with 9% of the total.

3.4.2.7 Fine Suspended Particulates (FSP) refers to suspended particulates with a nominal aerodynamic diameter of 2.5µm or less. According to the 2015 Hong Kong Emission Inventory Report published by EPD, marine vessel is the largest FSP emission source and accounted for 39% of the total emission in Year 2015. Vehicle was also a FSP emission source with 10% of the total.

3.4.2.8 Both RSP and FSP emissions would be increased by the induced marine traffic, which results in increased onshore concentrations near the new landing facility. RSP and FSP are also considered as key air pollutants of the Project. CBPs are major local dust emission sources, thus industrial RSP and FSP emissions by concrete batching are also considered in the assessment.

3.4.2.9 Sulphur dioxide (SO₂) is formed primarily from the combustion of sulphur-containing fossil fuels. According to the 2015 Hong Kong Emission Inventory Report released by EPD, marine vessel was the largest SO₂ emission source, account for 59% of the total emission in Year 2015. SO₂ is therefore one of the key air pollutants for the Project.

3.4.2.10 Vehicular SO₂ emission from had been substantially reduced (<1% of total according to the 2015 Hong Kong Emission Inventory Report) after the introduction of Euro V diesel from December 2007, whose sulphur content are capped at 0.001%. In view that road transport contributes only 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, Vehicular SO₂ emission would not be a critical concern.

3.4.2.11 Similarly, industrial sector had been using Euro V diesel since 2009. Starting from 1 October 2008, sulphur content of liquid fuel shall not exceed 0.005% for commercial and industrial process, according to the Air Pollution Control (Fuel Restriction) (Amendment) Regulation. However, owing to the close distance between the restaurants and ASRs, SO₂ emissions due to fuel combustion at restaurants are considered in the assessment.

3.4.2.12 Carbon Monoxide (CO) is a typical pollutant emitted from fossil fuel combustion and comes mainly from vehicle and marine vessel, accounting for 51% and 23% of the total emissions in Year 2015 respectively. With reference to the “Air Quality in Hong Kong 2016”, the highest 1-hour average (3130 µg/m³) and the highest 8-hour average (2,339 µg/m³) CO concentrations were recorded at the Causeway Bay roadside station and Tsuen Wan station respectively; these values were around one tenthth and one fifth of the respective AQO limits. In view that there is still a large margin to the AQOs, CO would not be a critical air pollutant of concern.

3.4.2.13 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 toxics. According to Assessment of Toxic Air Pollutant Measurements in Hong Kong Final Report, 2003, among the VOC compounds, benzene and 1,3-butadiene are the most significant ones for Hong Kong. The UK Air Quality Standards for benzene and 1,3-butadiene are 5.0 µg/m³ and 2.25 µg/m³ respectively according to the Air Quality Action Plan 2015, Medway Concil. Accordingly to “Air Quality in Hong Kong 2016”, annual average concentrations of benzene at EPD’s TAP monitoring stations were 2.27 µg/m³ and 1.17 µg/m³ for Tsuen Wan and Central/Western districts respectively. The levels of 1,3-butadiene were 0.10 µg/m³ and 0.07 µg/m³ for Tsuen Wan and Central/Western districts respectively. They are far below the UK Standards. Thus, VOCs are not considered as key pollutants for the Project.

Existing Industrial/Chimney Emission

3.4.2.14 There are 3 concrete batching operations identified within the 500m study area, which situate along Tung Yuen Street. In accordance with APCO, concrete batching plant (CBP) is classified as Specified Process (SP) for its significant contribution in air pollutant, in particular particulates emission. The industrial emissions from these CBPs also contribute to the cumulative air quality impact during operational phase. However, the impact is expected to be minor because the significant impact is generally localized at the boundary of the CBP.

3.4.2.15 With reference to the Specified Process (SP) License Registry maintained by EPD and the findings of the survey, the CBPs within 500m study area include:

• Cement Works (CBP) by China Concrete Co. Ltd. under SP Licence No. L-3-194(3)

• Cement Works (CBP) by Hong Kong Concrete Ltd. under SP Licence No. L-3-218(2)

• A non-SP CBP was found at 18 Tung Yuen Street, adjacent to the CBP by Hong Kong Concrete Ltd.

3.4.2.16 6 chimneys were identified at the Sam Ka Tsuen in a site visit conducted on 9 January 2018 and 15 May 2018. The details of the 6 chimneys and their locations are presented in Appendix 3.6. EC5 was no longer in use for cooking exhaust. Diesel was used as cooking fuel at EC1 and EC3 while Towngas was used at EC2, EC4 and EC6. Potential SO₂, NO_X and particulates emission would arise from diesel combustion and Towngas combustion at these restaurants. Towngas as a clean gaseous fuel which is produced from naphtha and natural gas, minimal SO₂ and particulates emission are expected. NO_X is the major air pollutant during Towngas combustion for cooking at commercial scale.

Odour from Sewage Discharges

3.4.2.17 According to the findings of the odour patrol, no odour source was identified in the existing condition. The Project itself does not constitute any element which would be odour emission sources. In addition, with the completion of the DSD project, Lei Yue Mun Village Sewerage project, potential odour nuisance would be unlikely occurred as mentioned in the Preliminary Environmental Review Report for Lei Yue Mun Village Sewerage (July 2017).

Odour from Maintenance Dredging

3.4.2.18 Maintenance dredging would be carried out to maintain sufficient water depth for vessels once every 5 to 10 years. The volume of sediment to be dredged during maintenance dredging would be approximately 3,056m³ at a rate of 1,200m³ per day. The period of maintenance dredging would be less than one week. Odour may arise from the sediments during the maintenance dredging activities, and temporary storage and transportation of the sediments if the sediments’ AVS content is high, and without proper management.

3.5 Assessment Methodology

3.5.1 Construction Phase

Fugitive Dust Emission from the Construction Sites

3.5.1.1 The construction programme, plant inventory and construction works areas were reviewed to evaluate the dust impacts from the construction sites to the nearby ASRs. Considering that the construction activities are limited and the scale of construction would be minor, qualitative approach was adopted for the assessment.

Odour from Capital Dredging

3.5.1.2 As discussed in Section 3.4.1.8, the magnitude of odour from sediment would depend on the levels of acid-volatile sulphide (AVS)[1]. Sediment grab sampling was conducted at three designated sampling stations identified in the Sediment Sampling and Testing Plan (SSTP) in October 2016. Sediment odour potential test was conducted to determine the levels of organic pollutants and odour potential of each sediment sub-samples collected at the designated sampling stations. The testing parameters are listed in Table 3.5. The details of the sampling methodology are presented in the SSTP in Appendix 7.2.

Table 3.5 Parameters for Sediment Odour Potential Test

Parameters	Reporting Limit	Preparation and Determination Method	Hong Kong Laboratory Accreditation Scheme (HOKLAS) Accreditation (Yes / No)
Sediment Oxygen Demand	10 mg/kg	In-house method based on APHA 19ed 5210B	No
Total Organic Carbon	0.05%	In-house method SOP154 (NDIR)	Yes
Total Sulphide	1.00 mg/kg	USEPA Method 9030B	No
Reduction-Oxidation (Redox) Potential	1 mV	Instrumental, Redox Meter (electrodemetric)	No
pH	pH 2.0 – 12.0	Instrumental, pH Meter (electrodemetric)	No
Acid Volatile Sulphide	1.00 mg/kg	USEPA Method 821/R91-100	Yes
Moisture Content	1%	APHA 19ed 2540G	Yes
Particle Size Distribution	0.1%	GEOSPEC 3:2001 Test 8.1	No

3.5.1.3 According to the laboratory results of the sediment grab sampling, the levels of AVS at the three designed monitoring stations were lower than the reporting limit of 1.00 mg/kg. The detailed test report is presented in Appendix 3.9. Therefore, odour impact from the sediment is considered insignificant, qualitative approach was adopted for the assessment.

3.5.2 Operation Phase

Vehicular Emission

3.5.2.1 The roads within 500m study area of the Project were identified. The predicted 24-hour traffic flow and vehicle compositions at the identified roads during operation phase were adopted from the Traffic Impact Assessment (TIA) to assess the potential air quality impact from the existing open road. The TIA has been approved by TD and the correspondence is attached in Appendix 3.3. The traffic data adopted for the assessment is also presented in this appendix.

3.5.2.2 EMFAC-HK v3.3 model was adopted to estimate the vehicle emission rates of NO, NO₂, RSP and FSP. The “vehicle fleet” refers to all motor vehicles operating on roads within this assessment area. The modelled fleet is broken down into 16 vehicle classes based on the information in the Transport Monthly Digest and vehicle population provided by EPD. The detailed input parameters and model assumptions made in EMFAC-HK model are summarized in Appendix 3.4.

3.5.2.3 The vehicular emission burdens of NO_x and RSP from commencement year to 15 years after, namely Year 2023, 2030 and 2038, were estimated with EMFAC-HK and are shown in Appendix 3.4. The vehicular emission attained the highest in Year 2023 and a decreasing trend was predicted in 15 years after project commencement. Year 2023 was therefore selected as the assessment year.

3.5.2.4 The resulting hourly emissions of NO, NO₂, RSP and FSP were divided by the number of vehicles and the distance travelled to obtain the emission factors in gram per miles per vehicle. The calculated 24-hour composite emission factors of 16 vehicle classes for each road type were then adopted in the subsequent air dispersion modelling. The detailed calculation of vehicular emission source is presented in Appendix 3.4.

Marine Traffic Emission

3.5.2.5 Making reference to the Marine Traffic Impact Assessment Review Report (MTIA) prepared under this Project, about 30 vessel trips (rounded-number) using the new LYM landing facility was estimated during peak hour. This represents 100% utilisation rate of landing step within an hour as a worst-case assumption.

3.5.2.6 The vessel count survey results for existing marine traffic and predicted project-induced marine traffic flows reported in the MTIA were adopted to assess the potential air quality impacts from the induced marine emissions during the operational phase of the Project.

3.5.2.7 According to the survey results of the MTIA, the total marine traffic volume for weekend was 11% higher than the one in weekday. Existing ferry services to/from Sam Ka Tsuen ferry pier was more demanding during weekend according to its ferry schedule. Therefore weekend marine traffic flow was assumed for all 365 days as worst case assumption.

3.5.2.8 The Eastern Fairway consists of four quarters, namely North Quarter, North Central Quarter, South Central Quarter and South Quarter. The marine traffic along the fairway in Year 2023 was estimated based on the observed average daily traffic by vessel types and quarters of the fairway in Year 2016 and the adopted annual growth rates for various kind of vessel types. Marine Department (MD) has no comments on the marine traffic data which is attached in Appendix 3.5.

3.5.2.9 The total marine traffic at Sam Ka Tsuen Ferry Pier derived from the ferry schedule of Year 2016 was reported in the MTIA. With reference to the timetable available by the operator Coral Sea Ferry, the marine traffic were separated into the one to/from Sai Wan Ho and to/from Tung Lung Chau. The marine traffic due to ferry service was assumed to be the same in Year 2023.

3.5.2.10 As a worst-case scenario, 100% utilization rate for the new landing facility was assumed in the MTIA, resulting in 30 local vessel trips per hour during peak hour. As reported in the MTIA, the operator expressed that they would consider to provide additional stop at the new Lei Yue Mun landing facility for ferries from Sam Ka Tsuen during the dining period (18:00 – 21:00). Ferry service with 7 vessels per hour in dining period will change to a circular route when the ferry is coming from Sai Wan Ho, after disembarking at the Sam Ka Tsuen Ferry Pier, the ferry would stop at the new landing facility and return to Sai Wan Ho Ferry. Additional sight-seeing tour during dining period with 4 vessels in peak hour from Tsim Sha Tsui to the new landing facility would be expected.

3.5.2.11 Other miscellaneous local vessels such as government vessels are also expected at the new Lei Yue Mun landing facility. Additional demand of 4 vessels in peak hour is expected.

3.5.2.12 Existing concrete batching operations requires transport of raw materials by sea. Dry bulk carrier is the typical local vessel used for carrying aggregate, river sand and cement to the CBPs. One carrier per hour was assumed to occupy an unloading spot throughout the operation hour of a CBP, typically 07:00 – 19:00, 12 hours a day. The carrier was also assumed to arrive at CBP at 07:00 and depart at 19:00.

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

Emission = P x FL x T x EF

where P is the installed power of equipment;

FL is fractional load of equipment in a specific mode;

T is operation time-in-mode; and

EF is fractional load emission factor of equipment

3.5.2.14 Typical power equipment installed on marine vessels are Main Engine (ME) for propulsion, Auxiliary Engine (AE) for electricity and Auxiliary Boiler (AB) for fuel pre-heating and pumping. Subject to the vessel types, different combinations of engines are equipped on a vessel. For example, all 3 kinds of engines are equipped on fully cellular container vessel, no ME for barge, and no AB for pleasure vessel.

3.5.2.15 The vessel types adopted in the MTIA were matched with equivalent vessel types considered in MVEIS. Typical engine power rating, engine type, fuel type of each vessel type were adopted from MVEIS. A summary of adopted vessel information is presented in Table 3.6. Detailed assumptions are discussed in Appendix 3.5.

3.5.2.16 According to the Air Pollution Control (Marine Light Diesel) Regulation, local vessel in Hong Kong should be using marine light diesel with sulphur content of 0.05%. Local vessels, including local ferries, dry bulk carriers for CBPs, government vessels and other local vessel in the proximity of Sam Ka Tsuen and the new landing facility, were assumed to use MGO, which is the equivalent fuel considered in MVEIS. The MGO considered in MVEIS is in sulphur content of 0.5%, therefore the SO₂ emission factors from MVEIS were further adjusted to sulphur content of 0.05% and are presented in Appendix 3.5. Otherwise, fuel types and its sulphur contents with reference to MVEIS are adopted in the assessment for ocean-going vessels along the fairway. Fuel type assumed for each vessel type is presented in Table 3.6.

Table 3.6 Adopted Parameters of Marine Vessel

Vessel Type in MTIA	MVEIS Classification
	Vessel Type	ME Engine Type	Fuel Type	ME Power Rating	AE Power Rating	AB Power Rating
Ocean-going vessels (along the Fairway)
Barge	Lighter/Barge/Cargo Junk	NA	MDO	NA	551	NA
Chinese Trading Vessels (CTV)	River Trade Vessel (FCCV)	DE	MGO	485	74	NA
Launches and Ferries (L&F)	Pleasure Vessel	HSD	MDO	786	60	NA
High Speed Vessels (HSV)	Macau Ferry	DE	MGO	6680	223	NA
Fishing Vessel (FV)	Fishing/Fish Processing Vessel	MSD	MDO	420	93	NA
Pleasure Vessel (PV)	Pleasure Vessel	HSD	MDO	786	60	NA
Bunker	Chemical Carrier/Tanker	MSD	HFO	3515	742	144
Government Vessel (Gov’t)	Others	MSD	HFO	7832	1739	57
Ocean-going Vessel (OGV)	FCCV	SSD	HFO	18104	956	313
Cruises	Cruise/Ferry	MSD	HFO	15184	4221	1000
Others	Others	MSD	HFO	7832	1739	57
Local vessels (Accessing Sam Ka Tsuen Ferry Pier, Sam Ka Tsuen Landing Steps, LYM New Landing Facility, Concrete Batching Plants)
Launches and Ferries (L&F)	Pleasure Vessel	HSD	MGO (sulphur content 0.05%)	786	60	NA
Government Vessel (Gov’t)	Others	MSD	MGO (sulphur content 0.05%)	7832	1739	57
Dry Bulk Carrier (Existing Concrete Batching Plant)	River Trade Vessel (Dry Bulk Carrier)	SSD	MGO (sulphur content 0.05%)	744	115	NA

Reference: Study on Marine Vessels Emission Inventory (MVEIS), HKUST, 2012

Remark: NA = Not Applicable, DE = Diesel Engine, HSD = High Speed Diesel Engine, MSD = Mid Speed Diesel Engine, SSD = Slow Speed Diesel Engine, HFO = Heavy Fuel Oil, MDO = Marine Diesel Oil, MGO = Marine Gas Oil

3.5.2.17 With referent to MVEIS, operation modes of vessel activity were determined based on the vessel speed. The operation mode definition by vessel speed is summarized in Table 3.7. The determination of operation mode at each marine source is discussed in Appendix 3.5.

Table 3.7 Operation Mode Definition by Vessel Speed

Operation Mode	Vessel Speed
Fairway Cruise	Over 12 knots
Slow Cruise	8 – 12 knots
Maneuvering	1 to 8 knots
Hotelling	Below 1 knot

Reference: Table 3-24, Study on Marine Vessels Emission Inventory (MVEIS), HKUST, 2012

3.5.2.18 Typical engine load factor by vessel type and by operation mode refers to MVEIS. Engine load factor of marine source was then determined according to its vessel type and its operation mode. Detailed determination of engine load factor is discussed in Appendix 3.5.

3.5.2.19 The time-in-mode was estimated by the distance and vessel speed travelled in the corresponding mode. The hoteling time of approaching vessel was assumed to be 10 minutes at ferry piers and 5 minutes at and landing steps respectively for the assessment purpose. The time-in-mode of marine sources are presented in Appendix 3.5.

3.5.2.20 Emission factors of SO₂, NO_X, RSP and FSP by vessel type and by operation mode refers to MVEIS. Together with the parameters discussed above, emission of a marine source is estimated with the equation discussed in Section 3.5.2.12. Detailed calculation of marine emission rates are derived in Appendix 3.5.

3.5.2.21 Marine emission is line source in nature because of the mobile vessels along the route. However, the emission also resembles point source for its high exhaust temperature, exhaust velocity and higher release height. In consideration of these similarities, the marine emission along a route was modelled by numerous of point sources along the route and its emission strength is equally allocated to these point sources.

3.5.2.22 For the modelling purpose, an average set of stack parameters was required for each type of modelled vessel. With reference to Emissions Processing and Sensitivity Air Quality Modelling of Category 3 Commercial Marine Vessel Emissions, USEPA and Generating an Hour-By-Hour Model-Ready Marine Emission Inventory, RWDI Air Inc. and Environment Canada, which were both presented US EPA 17th International Emission Inventory Conference, both studies applied the same set of stack parameters for all commercial vessels in SMOKE for plume rise calculation. The average set of stack parameters were based on compromised set from observations and studies by Corbett, J.J. and agreed among USEPA, Environment Canada (EC), and California Air Resources Board (CARB) via memo circulation. The compromised set of stack parameters for generic commercial vessel is shown in Appendix 3.5. The set of stack parameters is applicable to large vessel such as container ship, oil tanker, bulk carrier and cruise ship.

3.5.2.23 For specific vessels previously studied in the approved EIA, their stack parameters were extracted and adopted for the relevant types in the assessment. These vessels include barge, high speed vessel, cruise and tugboat. Stack parameters from previous studies are summarized in Appendix 3.5. For the rest of the vessel types, stack parameters were assumed as far as possible according to their nature or size. Details of assumptions were presented in the same appendix.

3.5.2.24 Stack height and diameter of each vessel were further verified and determined based on the observation. Photo of typical vessel of each vessel type is presented in Appendix 3.5.

3.5.2.25 Moreover, high speed vessels, fishing vessels, pleasure vessels, government vessels (mostly patrol boats) and others (mostly tugboats) generally equips with horizontal stack. These vessels were therefore modelled as point source with horizontal release in AERMOD.

3.5.2.26 Stack parameters, namely stack height, exit temperature, exit velocity, stack diameter and effective diameter, adopted for each vessel type are summarized in Appendix 3.5.

Industrial Emission

3.5.2.27 The valid emission strength, corresponding dust control measure of emission sources and their emission duration of those adjacent plant operations were extracted from the SP Licence Registry whichever is applicable and taken into account in this assessment. Locations of dust emission sources were determined based on aerial photo and observation during site visit. Spatial distribution of these adjacent dust emission sources and their emission details are presented in Appendix 3.6.

3.5.2.28 For the non-SP CBP, site visit was conducted on 3^rd March 2017 and its operation activity such as truck movement was observed. The emission rates were then estimated according to the site observations. The detailed calculation of its emission rates is presented in Appendix 3.6 as well.

3.5.2.29 Diesel fuel consumption at EC3 and Towngas fuel consumption at EC2 were obtained from the restaurant owners. Fuel consumptions at other chimneys were estimated based on their relative sizes sto the restaurant with similar fuel type and known fuel consumption, i.e. EC1 based on EC3, and EC4 and EC6 based on EC2. The emission factors of diesel and natural gas combustion refers to Section 1.3 and Section 1.4, AP-42, USEPA respectively. The stack parameters, including exit temperature and exit velocity, refer to the boiler of restaurant addressed in the approved EIA Study “Central Kowloon Route” (AEIAR-171/2013). Their stack height and diameters were determined by observation. The calculation of emission rates is presented in Appendix 3.6.

Background Contributions

3.5.2.30 According to “Guidelines on Assessing the ‘TOTAL’ Air Quality Impacts”, an integrated modelling system PATH-2016 (Pollutants in the Atmosphere and their Transport over Hong Kong) which is developed and maintained by EPD is applied to estimate the background pollutant concentrations. Year 2020 background concentrations from PATH-2016 is adopted to estimate future concentrations scenario in Year 2023.

3.5.2.31 The study area covers 2 grid cells of PATH-2016, namely grid (46, 30) and (47, 30). PATH-2016 dataset of these 2 grid cells are extracted as the background concentration for the assessment. Extracted parameters include NO₂, SO₂, RSP and FSP.

3.5.2.32 As dataset of PATH-2016 consist only the background concentration of RSP, daily and annual average FSP background concentrations are estimated by a factor of 0.75 and 0.71 to RSP concentration respectively, as suggested by “Guidelines on the Estimate of PM_2.5 for Air Quality Assessment in Hong Kong”.

Dispersion Modelling & Modelling Approach

3.5.2.33 American Meteorological Society (AMS) and U.S. Environmental Protection Agency (EPA) Regulatory Model (AERMOD), the EPD approved air dispersion model, is employed to predict the air quality impacts due to marine emission and industrial emission.

3.5.2.34 The heights of the ASRs identified within the study area are not higher than 10mAG, the assessment heights of the ASR are therefore at 1.5mAG (pedestrian level), 5mAG or 10mAG, whichever is lower or equal to its physical height.

3.5.2.35 Based on the predictions of the discrete receptors, the worst hit level on ASRs was identified, at which the predicted concentrations are found to be the highest among the assessment heights. Contour plots of cumulative pollutant concentrations at this level were then obtained to investigate the spatial distribution of potential air quality impact.

3.5.2.36 Hourly meteorological conditions including wind data, temperature, relative humidity, pressure cloud cover and mixing height of Year 2010 are extracted from the WRF meteorological data adopted in the PATH-2016 system. The minimum wind speed is capped at 1 metre per second. The mixing height is capped between 121 metres and 1667 metres according to the observation in Year 2010 by HKO. The height of the input data is assumed to be 9 above ground for the first layer of the WRF data as input. The met data is input as on-site data into AERMET.

3.5.2.37 Surface characteristic parameters such as albedo, Bowen ratio and surface roughness are required in the AERMET (the meteorological pre-processor of AERMOD). The land use characteristics of the surrounding are classified and these parameters of each landuse are then suggested by AERMET by default according to its land use characteristics. The detailed assumptions are discussed in Appendix 3.7.

3.5.2.38 CALINE4, the USEPA approved line source air dispersion model developed by the California Department of Transport is used to assess vehicular emission from identified road within 500m study area.

3.5.2.39 The surface roughness is dependent on the land use characteristics, which is estimated to be 10% of average height of physical structure within 1 km radius of the Project site. Sea surface is the abundant area in the study area and abundant 2-storey low-rise are identified along the coast, the surface roughness applied in the CALINE4 model is thus taken as 100 cm for the surface with low-rise features.

3.5.2.40 Under the current EPD guideline, the hourly meteorological data including wind speed, wind direction, and air temperature from the relevant grids from the WRF Meteorological data (same basis for PATH-2016 model), are employed for the model run. PCRAMMET is applied to generate Pasquill-Gifford stability class for the meteorological input to CALINE4 model based on the WRF meteorological data.

3.5.2.41 Ozone Limiting Method (OLM) has been adopted for the conversion of NO_X to NO₂ based on the ozone background concentration from PATH-2016. NO₂-to-NO_X ratio of 10% for the marine diesel engine is assumed.

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

where

[NO₂]_predicted is the predicted NO₂ concentration

[NO_X]_predicted is the predicted NOX concentration

MIN menas the minimum of the two values within the brakect

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

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

3.5.2.42 Regarding vehicular emission, NO₂ and NO are predicted separately in CALINE4. Following the principle of OLM, the total predicted vehicular NO₂ is estimated as below:

[NO₂]_vehicular = [NO₂]_predicted + MIN {[NO]_predicted, or (46/48) ´ [O₃]_PATH}

where

[NO₂]_vehicular is the total predicted vehicular NO₂ concentration

[NO₂]_predicted is the predicted NO₂ concentration

[NO]_predicted is the predicted NO concentration

MIN menas the minimum of the two values within the brakect

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

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

3.5.2.43 According to “Guidelines on the Estimation of 10-min average SO₂ Concentration for Air Quality Assessment in Hong Kong”, SO₂ concentration in 10-min average due to the marine emission is estimated by applying stability-dependent multiplicative factor to 1-hour average model prediction by AERMOD.

Odour from Sewage Discharges and Maintenance Dredging

3.5.2.44 As mentioned in Section 3.4.2.7, no odour nuisance is anticipated after completion of the DSD’s Lei Yue Mun Village Sewerage project. In view of the limited dredging volume and short duration together with the laboratory results of the sediment grab sampling (discussed in Section 3.5.1), odour impact from the maintenance dredging is considered insignificant. Qualitative assessment approach was adopted to address potential odour issues during operational phase of the Project.

3.6 Prediction and Evaluation of Environmental Impacts

3.6.1 Construction Phase

Fugitive Dust Emission from the Construction Sites

3.6.1.1 Construction activities would be conducted at the coastal area at LYM for construction of the proposed breakwater and public landing facilities, and improvement works at the existing lookout points 1, 3, 4 and 5, and the existing viewing platform. For the dredging works for breakwater and public landing facilities, since the moisture content of dredged materials is very high, no dust emission is anticipated from the dredging activities. As for the construction activities for breakwater, deck structure, wave absorption chamber and deck furniture, the total construction period would be limited to seven months only (refer to Appendix 2.1), such that any potential fugitive dust emission from the activities would be temporary.

3.6.1.2 The works areas of the proposed the existing lookout points 1, 3, 4 and 5, the existing viewing platform are only approximately 12 m², 31 m², 32 m², 95 m² and 147 m², respectively. The improvement works of each lookout point and the viewing platform would last four to six months only. In addition, the works for lookout points would be conducted in two phases, once the completion of the works for lookout point No. 1 and 3, the works for lookout point No. 4 and 5 would then commence, it would limit the dust impact. Albeit the Project site would be in close proximity to the ASRs, considering that the works areas of the Project are limited, the construction activities will be localised and in phasing, and the construction period would be short, dust emissions would be insignificant and could be well controlled through the dust suppression measures as stipulated in the Air Pollution Control (Construction Dust) Regulation (Cap. 311R) of Air Pollution Control Ordinance (APCO) (Cap. 311) and good site practices as described in Section 3.7.1. Cumulative dust impact with the concurrent project, Lei Yue Mun Village Sewerage project, is therefore not anticipated.

3.6.1.3 As presented in Section 3.4.1.5, beautification works and streetscape improvement works would not pose adverse dust impact. With proper implementation of the dust suppression measures, adverse air quality impact due to the construction of the Project would not be anticipated.

Odour from Capital Dredging

3.6.1.4 Dredging would be required in the seafront fronting the proposed landing step to provide sufficient depth of water for vessels. Marine site investigation and laboratory testing have been conducted in October 2016 to determine the contamination level of the sediments within the proposed dredging area. The levels of acid volatile sulphide (AVS) were measured for the sediment samples collected under the marine site investigation to assess the potential odour impact from the dredged sediment. In general, AVS is an indicator of odorous sulphides present in sediment, high AVS concentrations in sediment indicate that odorous hydrogen sulphide gas is likely to be generated from the sediment[2]. According to the laboratory results of the sediment grab sampling, the levels of AVS at the three designed monitoring stations were lower than the reporting limit of 1.00 mg/kg. The detailed test report is presented in Appendix 3.9.

3.6.1.5 Referring to the Planning Review, Situation Report on Odour Issue of Kai Tak Development prepared in 2006 under Agreement No. CE 4/2004 (TP) South East Kowloon Development Comprehensive Planning and Engineering Review Stage 1, the measured AVS levels of the sediments collected at Shing Mun River, which was bioremediated for odour issue, ranged from 90 to 100 mg/kg. These sediments were considered to have been remediated to a level with minimum odour impact to the surrounding environment. While the levels of AVS measured at all the monitoring stations for the Project were lower than the reporting limit of 1.00 mg/kg, which are far below the AVS levels of the remediated sediments at Shing Mun River, it is expected that the potential odour emissions from the sediments within the dredging area would be minimal.

3.6.1.6 The dredging scale proposed under the Project is small. The total volume of dredged sediments generated from the dredging operation would be approximately 12,625 m³ and the dredging work would be conducted by one dredger (of about 8 m³ capacity) at a dredging rate of no more than 1,200 m³ per day. In view of the transient nature of the dredging work and small dredging scale, and negligible odour emission from the sediment based on the findings of the laboratory test, odour nuisance would not be expected during dredging and transportation of the dredged sediment with the adoption of the good site practice as mentioned in Section 3.7.3.1.

3.6.2 Operational Phase

3.6.2.1 The cumulative air quality impact during the operation phase at the representative ASRs was evaluated. The predicted cumulative 10^th highest daily and annual average of RSP and FSP, 19^th highest hour and annual average of NO₂, and 4^th highest 10-min and daily average of SO₂ concentrations are summarized in Table 3.8 – Table 3.15 respectively. The detailed prediction results are presented in Appendix 3.8.

3.6.2.2 The assessment results indicated that there is a trend increase in the air pollutant concentrations from ground level to 10mAG, and the highest levels would occur at 10mAG of all discrete receptors.  The worst hit level at the representative ASRs would appear at 10mAG, based on the predictions at the discrete receptors. Contour plots of the cumulative pollutant concentrations at 10 mAG were thus predicted and presented in the same appendix. The predictions indicate that the predicted NO₂, SO₂, RSP and FSP concentrations at all representative ASRs would comply with the respective AQOs.

3.6.2.3 Based on the contour plots presented in Appendix 3.8, exceedance of cumulative particulate matters concentrations at 10 mAG were predicted, which was confined within the boundaries of CBPs. However, no existing or planned sensitive use is identified at 10 mAG within these areas. Furthermore, the contour results showed that high concentration of pollutants are caused by the dusty operation of the CBPs, as well as berthing of dry bulk carriers while unloading. The operations of CBPs are the major contributors to the adverse air quality within the boundaries of CBPs.

3.6.2.4 Also, exceedance of cumulative 10-min average SO₂ and hourly average NO₂ concentrations were predicted at 10 mAG of the proposed promenade (landing facility) P3. However, no existing or planned sensitive use at 10 mAG is identified in the exceedance area. In order to confirm the acceptability of air quality at pedestrian level, contour plots of the cumulative 10-min average SO₂ and hourly NO₂ concentrations at 1.5mAG were also predicted and are presented in the Appendix 3.8. No exceedance of cumulative 10-min average SO₂ and hourly NO₂ concentrations at 1.5mAG was predicted near the new landing facility. No adverse air quality impact would be expected at pedestrian level of the proposed promenade.

3.6.2.5 In conclusion, the air pollutant contributions by the project-induced marine emissions are expected to be minor. The prediction further showed that the operation of the proposed Lei Yue Mun landing facility would not cause adverse air quality impact on any ASR within the study area.

Table 3.8 Worst Predicted Cumulative Daily RSP Concentration during Operation Phase

ASR ID	10^th Highest 24-hr RSP Concentrations (µg/m^3)
	Existing Vehicles	Existing Concrete Batching Plants	Existing Chimneys	Existing & Project Induced Marine	Existing Ambient Background	Total
A1	<1	<1	<1	<1	73	73
A2	<1	<1	<1	<1	73	73
A3	<1	<1	<1	<1	73	73
A4	<1	<1	<1	<1	73	73
A5	<1	<1	<1	<1	73	73
A6	<1	<1	<1	<1	73	73
A7	<1	<1	<1	<1	73	73
A8	<1	<1	<1	<1	73	73
A9	<1	<1	<1	<1	73	73
A10	<1	<1	<1	<1	73	74
A11	<1	<1	<1	<1	73	74
A12	<1	<1	<1	<1	73	74
A13	<1	<1	<1	<1	73	74
A14	<1	<1	<1	<1	73	74
A15	<1	<1	<1	<1	73	74
A16	<1	<1	<1	<1	73	74
A17	<1	<1	<1	<1	73	74
P1	<1	<1	<1	<1	73	73
P2	<1	<1	<1	<1	73	73
P3	<1	<1	<1	<1	73	73

Table 3.9 Worst Predicted Cumulative Annual RSP Concentration during Operation Phase

ASR ID	Annual RSP Concentrations (µg/m^3)
	Existing Vehicles	Existing Concrete Batching Plants	Existing Chimneys	Existing & Project Induced Marine	Existing Ambient Background	Total
A1	<1	<1	<1	<1	32	33
A2	<1	<1	<1	<1	32	33
A3	<1	<1	<1	<1	32	33
A4	<1	<1	<1	<1	32	33
A5	<1	<1	<1	<1	32	33
A6	<1	<1	<1	<1	32	33
A7	<1	<1	<1	<1	32	32
A8	<1	<1	<1	<1	32	32
A9	<1	<1	<1	<1	32	32
A10	<1	<1	<1	<1	32	32
A11	<1	<1	<1	<1	32	32
A12	<1	<1	<1	<1	32	32
A13	<1	<1	<1	<1	32	32
A14	<1	<1	<1	<1	32	32
A15	<1	<1	<1	<1	32	32
A16	<1	<1	<1	<1	32	32
A17	<1	<1	<1	<1	32	32
P1	<1	<1	<1	<1	32	33
P2	<1	<1	<1	<1	32	33
P3	<1	<1	<1	<1	32	32

Table 3.10 Worst Predicted Cumulative Daily FSP Concentration during Operation Phase

ASR ID	10^th Highest 24-hr FSP Concentrations (µg/m^3)
	Existing Vehicles	Existing Concrete Batching Plants	Existing Chimneys	Existing & Project Induced Marine	Existing Ambient Background	Total
A1	<1	<1	<1	<1	55	55
A2	<1	<1	<1	<1	55	55
A3	<1	<1	<1	<1	55	55
A4	<1	<1	<1	<1	55	55
A5	<1	<1	<1	<1	55	55
A6	<1	<1	<1	<1	55	55
A7	<1	<1	<1	<1	55	55
A8	<1	<1	<1	<1	55	55
A9	<1	<1	<1	<1	55	55
A10	<1	<1	<1	1	55	56
A11	<1	<1	<1	1	55	56
A12	<1	<1	<1	1	55	56
A13	<1	<1	<1	<1	55	55
A14	<1	<1	<1	<1	55	55
A15	<1	<1	<1	<1	55	55
A16	<1	<1	<1	<1	55	55
A17	<1	<1	<1	<1	55	55
P1	<1	<1	<1	<1	55	55
P2	<1	<1	<1	<1	55	55
P3	<1	<1	<1	<1	55	55

Table 3.11 Worst Predicted Cumulative Annual FSP Concentration during Operation Phase

ASR ID	Annual FSP Concentrations (µg/m^3)
	Existing Vehicles	Existing Concrete Batching Plants	Existing Chimneys	Existing & Project Induced Marine	Existing Ambient Background	Total
A1	<1	<1	<1	<1	23	23
A2	<1	<1	<1	<1	23	23
A3	<1	<1	<1	<1	23	23
A4	<1	<1	<1	<1	23	23
A5	<1	<1	<1	<1	23	23
A6	<1	<1	<1	<1	23	23
A7	<1	<1	<1	<1	23	23
A8	<1	<1	<1	<1	23	23
A9	<1	<1	<1	<1	23	23
A10	<1	<1	<1	<1	23	23
A11	<1	<1	<1	<1	23	23
A12	<1	<1	<1	<1	23	23
A13	<1	<1	<1	<1	23	23
A14	<1	<1	<1	<1	23	23
A15	<1	<1	<1	<1	23	23
A16	<1	<1	<1	<1	23	23
A17	<1	<1	<1	<1	23	23
P1	<1	<1	<1	<1	23	23
P2	<1	<1	<1	<1	23	23
P3	<1	<1	<1	<1	23	23

Table 3.12 Worst Predicted Cumulative Hourly NO₂ Concentration during Operation Phase

ASR ID	19^th Highest Hourly NO2 Concentration (µg/m^3)
	Existing Vehicles	Existing Concrete Batching Plants	Existing Chimneys	Existing & Project Induced Marine	Total
A1	<1	<1	10	100	111
A2	<1	<1	99	34	133
A3	<1	<1	3	108	111
A4	<1	<1	110	28	138
A5	<1	<1	<1	110	110
A6	<1	<1	11	100	111
A7	<1	<1	<1	111	111
A8	<1	<1	12	100	112
A9	<1	<1	<1	113	113
A10	<1	<1	119	15	135
A11	<1	<1	33	105	137
A12	<1	<1	71	67	138
A13	1	<1	<1	112	113
A14	1	<1	<1	112	113
A15	1	<1	<1	112	113
A16	<1	<1	<1	132	132
A17	2	<1	<1	113	115
P1	<1	<1	15	97	112
P2	<1	<1	15	97	112
P3	<1	<1	<1	113	113

Table 3.13 Worst Predicted Cumulative Annual NO₂ Concentration during Operation Phase

ASR ID	Annual NO2 Concentration (µg/m^3)
	Existing Vehicles	Existing Concrete Batching Plants	Existing Chimneys	Existing & Project Induced Marine	Total
A1	<1	<1	2	14	16
A2	<1	<1	4	14	18
A3	<1	<1	2	14	17
A4	<1	<1	4	14	19
A5	<1	<1	2	14	17
A6	<1	<1	3	14	17
A7	<1	<1	3	14	17
A8	<1	<1	3	14	17
A9	<1	<1	3	14	17
A10	<1	<1	5	13	18
A11	<1	<1	5	13	18
A12	<1	<1	5	13	18
A13	<1	<1	3	13	16
A14	<1	<1	3	13	16
A15	<1	<1	3	13	16
A16	<1	<1	5	13	18
A17	<1	<1	4	13	16
P1	<1	<1	3	14	17
P2	<1	<1	3	14	17
P3	<1	<1	3	14	17

Table 3.14 Worst Predicted Cumulative 10-min SO₂ Concentration during Operation Phase

ASR ID	4^th Highest 10min SO2 Concentration (µg/m^3)
	Existing Chimneys	Existing & Project Induced Marine	Existing Ambient Background	Total
A1	<1	<1	110	110
A2	<1	119	27	147
A3	<1	<1	110	110
A4	<1	120	27	147
A5	<1	35	77	112
A6	<1	39	77	116
A7	<1	38	77	115
A8	<1	40	77	117
A9	<1	40	77	117
A10	<1	136	23	159
A11	<1	137	23	160
A12	<1	139	23	163
A13	<1	46	76	122
A14	<1	47	76	123
A15	<1	47	76	123
A16	<1	75	78	153
A17	<1	50	76	126
P1	<1	41	77	118
P2	<1	42	77	119
P3	<1	44	77	121

Table 3.15 Worst Predicted Cumulative Daily SO₂ Concentration during Operation Phase

ASR ID	4^th Highest Daily SO2 Concentration (µg/m^3)
	Existing Chimneys	Existing & Project Induced Marine	Existing Ambient Background	Total
A1	<1	1	23	24
A2	<1	1	24	25
A3	<1	1	23	25
A4	<1	1	24	26
A5	<1	2	23	25
A6	<1	2	23	25
A7	<1	1	24	25
A8	<1	1	24	25
A9	<1	2	23	25
A10	<1	7	20	27
A11	<1	7	21	27
A12	<1	7	21	28
A13	<1	3	21	25
A14	<1	3	21	25
A15	<1	3	21	25
A16	<1	6	21	28
A17	<1	4	21	25
P1	<1	1	24	25
P2	<1	1	24	25
P3	<1	2	23	26

Odour from Sewage Discharge

3.6.2.6 There is currently only limited public sewerage system laid up to the end of Lei Yue Mun Praya Road that is located just outside Lei Yue Mun Village (details of the existing sewerage system is described in Section 6.2). Following the completion of the sewerage improvement works to be undertaken by DSD under Lei Yue Mun Village Sewerage project, the sewage arisen from the Project will be received by the future sewerage system where new rising mains with dry weather flow interceptors (DWFIs), pumping chambers and manholes within LYM village will be constructed. The existing Sam Ka Tsuen Pumping Chamber, and the existing sewers at Lei Yue Mun Praya Road and Lei Yue Mun Path will also be upgraded. These sewerage facilities may generate odour emissions; however, they will be located underground; the pumping chambers and the DWFIs will all also be enclosed. With the above design, the potential odour impact from these sewerage facilities is expected to be negligible. With the provision of the proposed sewers, sewage would not be discharged into the storm drains, and therefore would not result in odour nuisance. Regarding the existing Sam Ka Tsuen Pumping Chamber, there is no odour complaint received according to DSD record. The upgraded works would only increase the total area from 16 m² to 20 m², and the new pump will be covered, it is anticipated that the operation of the upgraded Sam Ka Tsuen Pumping Chamber would be similar to the existing operation, odour nuisance to the surroundings ASRs would not be anticipated. Upon completion of DSD’s improvement works, no odour nuisance due to sewage issues in the study area would be anticipated. This aligns with the findings in the Preliminary Environmental Review Report of Lei Yue Mun Village Sewerage (under Lei Yue Mun Village Sewerage project) which concluded that no adverse odour impact from this sewerage improvement project would be anticipated.

Odour from Maintenance Dredging

3.6.2.7 As discussed in Section 3.5.2.44, approximately 3,056m³ of sediment would need to be dredged once every 5 to 10 years. This volume of sediment would require one grab dredger only and the dredging period would be less than one week. The volume of sediment to be dredged during maintenance dredging would be significantly lower than the volume of capital dredging during the construction phase. Further, the period of maintenance dredging would also be much shorter than that during capital dredging. In addition, given the continual improvement of sewage collection and treatment in Hong Kong, it is not expected that the sediment quality in the study area would deteriorate in the future. Thus, similar to the above assessment on capital dredging, negligible odour impact on ASRs due to maintenance dredging is expected with the adoption of the good site practice as mentioned in Section 3.7.3.1.

3.7 Mitigation of Adverse Environmental Impacts

3.7.1 Construction Phase

Dust Emission from the Construction Sites

3.7.1.1 Sufficient dust suppression measures as stipulated under the Air Pollution Control (Construction Dust) Regulation (Cap 311R) and good site practices should be properly implemented in order to minimize the construction dust generated. The measures include the followings:

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

• Use of frequent watering of particular dusty construction areas close to ASRs;

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

• Open temporary stockpiles should be avoided or covered. Prevent placing dusty material storage plies near ASRs;

• Tarpaulin covering of all dusty vehicle loads transported to, from and between site locations;

• Establishment and use of vehicle wheel and body washing facilities at the exit point of the site;

• Imposition of speed control for vehicles on unpaved site roads. 8 km/hr is the recommended limit;

• Routing of vehicles and positioning of construction plant should be at the maximum possible distance from ASRs.

3.7.1.2 Guidelines stipulated in EPD’s Recommended Pollution Control Clauses for Construction Contracts should also be incorporated in the contract documents to abate dust impacts. The clauses include:

• The Contractor shall observe and comply with the Air Pollution Control Ordinance and its subsidiary regulations, particularly the Air Pollution Control (Open Burning) Regulation, Air Pollution Control (Construction Dust) Regulation and Air Pollution (Smoke) Regulation.

• The Contractor shall undertake at all times to prevent dust nuisance and smoke as a result of the construction activities.

• The Contractor shall ensure that there will be adequate water supply / storage for dust suppression.

• The Contractor shall devise, arrange methods of working and carrying out the works in such a manner so as to minimise dust impacts on the surrounding environment, and shall provide experienced personnel with suitable training to ensure that these methods are implemented.

• Before the commencement of any work, the Contractor may require to submit the methods of working, plant, equipment and air pollution control system to be used on the site for the Engineer inspection and approval.

3.7.2 Operational Phase

3.7.2.1 No adverse air quality impact is anticipated during the operational phase of the Project, thus mitigation measure is deemed not necessary.

3.7.3 Odour from Sediments from Capital Dredging and Maintenance Dredging

3.7.3.1 Potential odour impact arising from the dredging activities during both construction and operation phase are not anticipated, thus mitigation measure is deemed not necessary. Nevertheless, the following precautionary measures are proposed to minimize the potential impacts:

· Loading of the dredged sediment to the barge should be controlled to avoid splashing and overflowing of the sediment slurry to the surrounding water.

· Any dredged sediment should be stored in enclosed tanks or properly covered as far as practicable to minimise its exposed area during its temporary storage and should be placed as far away from the identified ASRs as practically possible.

· Dredging rate should be controlled carefully.

· The dredged sediment is suggested to be delivered off-site for disposal every day as possible to avoid the dredged sediment for storage at the barge overnight.

· Dredged sediment placed on marine vessel for disposal should also be properly covered during transportation.

· The dredging activities are conducted during non-summer season as possible.

3.7.3.2 With the implementation of these measures, the potential odour nuisance could be minimized and adverse odour impact at nearby ASRs is not expected.

3.8 Evaluation of Residual Impacts

3.8.1 Construction Phase

3.8.1.1 No adverse residual air quality impact is anticipated from the construction phase of the Project provided that the mitigation measures proposed in Section 3.7.1 are properly implemented.

3.8.2 Operational Phase

3.8.2.1 No adverse residual air quality impact is anticipated from the operational phase of the Project.

3.9 Environmental Monitoring and Audit

3.9.1 Construction Phase

3.9.1.1 Weekly site audit is recommended to be conducted in order to ensure the proposed mitigation measures are implemented in an appropriate manner and are effective.

3.9.2 Operational Phase

3.9.2.1 Since no adverse air quality impact is anticipated during the operational phase of the Project, monitoring and audit is deemed unnecessary.

3.10 Conclusion

3.10.1 Construction Phase

3.10.1.1 With implementation of sufficient dust suppression measures as stipulated under the Air Pollution Control (Construction Dust) Regulation (Cap 311R) and good site practices, adverse construction dust impact is not expected on the surrounding ASRs. Requirements of Air Pollution Control (Construction Dust) Regulation and EPD’s Recommended Pollution Control Clauses for Construction Contracts are proposed to be incorporated into the contract. Odour impact is not anticipated from the dredging activities and good site practices are recommended during dredging and transportation of the dredged sediment.

3.10.2 Operational Phase

3.10.2.1 Potential cumulative air quality impacts due to marine emission arising from the marine traffic induced by the Project and the secondary air pollution contributors (marine emission industrial emission and vehicular emission) within 500m study area during operation phase of the Project is assessed. Based on the estimations in the TIA and MTIA and the predictions by air quality models, the induced marine traffic would be minor and unlike to cause adverse air quality impacts to the nearby ASRs. The predicted air pollutants concentrations at the ASRs due to cumulative air quality impacts would comply with the AQOs. Odour impact is not anticipated from the maintenance dredging. Odour nuisance on the ASRs is also not expected as there is no odour emission source arising from the Project and no other odour emission source is found within the Project area.

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[1] Volume 7 Annex A, Kai Tak Development EIA Report (EIA-157/2008)

[2] Volume 7 Annex A, Kai Tak Development EIA Report (EIA-157/2008)