Contents

 

                                                                                                                                                                                             

3            Air Quality  3-1

3.1           Legislation, Standards and Guidelines  3-1

3.2           Description of the Environment 3-3

3.3           Assessment Area and Air Sensitive Receivers  3-6

3.4           Construction Air Quality Impact Assessment 3-7

3.5           Operational Air Quality Impact Assessment 3-12

3.6           Conclusion  3-13

3.7           References  3-14

 

 

 

 

 

 

Figures

Figure 3.1              Locations of Representative Air Sensitive Receivers and Concerned PATH Grids

Do not delete this. This is for Table Number.

 

 

 

 

 

 

 

3                                Air Quality

3.1                         Legislation, Standards and Guidelines

3.1.1                    General

3.1.1.1                The relevant legislation, standards and guidelines applicable to this Study for the assessment of air quality impacts include:

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

·               Air Pollution Control (Construction Dust) Regulation (Cap. 311R);

·               Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation (Cap. 311Z);

·               Air Pollution Control (Marine Light Diesel) Regulation (Cap. 311Y);

·               Air Pollution Control (Fuel for Vessels) Regulation (Cap. 311AB);

·               Environmental Impact Assessment Ordinance (EIAO) (Cap. 499), including Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM), Section 1 of Annex 4, and Annex 12; and

·               Hong Kong Planning Standards and Guidelines (HKPSG).

3.1.2                    Air Pollution Control Ordinance

3.1.2.1                The principal legislation for controlling air pollutants is the Air Pollution Control Ordinance (APCO) (Cap. 311) and its subsidiary regulations, which defines statutory Air Quality Objectives (AQOs).

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

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

·           Ensure that the AQOs for 7 common air pollutants are met as soon as possible.

3.1.2.3                Currently, the AQOs stipulate limits on concentrations for seven pollutants including sulphur dioxide (SO2), Respirable Suspended Particulates (RSP), Fine Suspended Particulates (FSP), Nitrogen Dioxide (NO2), Carbon Monoxide (CO), photochemical oxidants, (As Ozone (O3)) and Lead (Pb).  The prevailing AQOs are listed in Table 3.1.

Table 3.1         Hong Kong Air Quality Objectives

Pollutant

Limits on Concentration, µg/m3 [1]

(Number of exceedances allowed per year in brackets)

10-min

1-hr

8-hr

24-hr [2]

Annual [2]

Sulphur Dioxide (SO2)

500

(3)

 

 

125

(3)

 

Respirable Suspended Particulates (RSP) [3]

 

 

 

100

(9)

50

(N.A[5])

Fine Suspended Particulates (FSP) [4]

 

 

 

75

(9)

35

(N.A[5])

Carbon Monoxide (CO)

 

30,000

(0)

10,000

(0)

 

 

Nitrogen Dioxide (NO2)

 

200

(18)

 

 

40

(N.A[5])

Ozone (O3)

 

 

160

(9)

 

 

Lead (Pb)

 

 

 

 

0.5

(N.A[5])

Notes:

[1]     Measured at 293K and 101.325kPa.

[2]     Arithmetic mean.

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

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

[5]     N.A – Not Applicable.

3.1.3                    Air Pollution Control (Construction Dust) Regulation

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

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

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

3.1.5                    Air Pollution Control (Marine Light Diesel) Regulation

3.1.5.1                Since 1 April 2014, a statutory cap of 0.05% m/m on the sulphur content of locally supplied marine light diesel has been imposed to reduce air pollution from the marine sector under the Air Pollution Control (Marine Light Diesel) Regulation. The prohibition applies to vessels within the waters of Hong Kong.

3.1.6                    Air Pollution Control (Fuel for Vessels) Regulation

3.1.6.1                During its stay in the waters of Hong Kong, a vessel is prohibited from using any fuel other than compliant fuel for combustion purposes for operating any of its specified machinery, which includes the main engine, auxiliary engine, boiler and generator.

3.1.7                    Environmental Impact Assessment Ordinance (EIAO) and Technical Memorandum on Environmental Impact Assessment Process (TM-EIAO)

Total Suspended Particulate Criteria

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

Odour Criterion

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

3.2                         Description of the Environment

3.2.1                    Existing Ambient Air Quality Conditions

3.2.1.1                EPD operates a number of air quality monitoring stations in Hong Kong. The nearest air quality monitoring station to the Site is at Tap Mun. The latest 5 years monitoring data (available up to 2019) of various air pollutants monitored at Tap Mun air quality monitoring station is presented in Table 3.2 and is compared with the AQOs for information.

Table 3.2         Air Quality Monitoring Data at Tap Mun Station (2015 – 2019)

Pollutant

Parameter

Concentrations (μg/m3)

AQOs (μg/m3)

2015

2016

2017

2018

2019

5-year mean

SO2

4th highest 10-minutes

50

45

32

29

19

35
[7%]

500 (3)

4th highest 24-hour

14

15

14

13

12

14 [11%]

125 (3)

NO2

19th highest 1-hour

51

58

52

51

56

54 [27%]

200 (18)

Annual

10

10

10

11

10

10 [25%]

40 (N/A)

CO

Max. 1-hour

2,140

1,470

1,770

1,170

1,360

1,582 [5%]

30,000 (0)

Max. 8-hour

1,351

1,453

1,543

1,151

1,350

1,370 [14%]

10,000 (0)

O3

10th highest 8-hour

182

169

192

184

212

188 [118%]

160 (9)

RSP

10th highest 24-hour

86

68

74

60

64

70 [70%]

100 (9)

Annual

35

30

35

31

31

32 [64%]

50 (N/A)

FSP

10th highest 24-hour

66

43

43

32

35

44 [59%]

75 (9)

Annual

24

19

20

17

17

19 [54%]

35 (N/A)

Notes:

[1]    N/M - Not Measured; N/A – Not Available.

[2]    Number of exceedance allowed under the AQO is shown in round brackets ( ), % of the AQO is shown in square brackets [ ]. The 5-year mean is the average of the yearly maximum.

[3]    Monitoring results exceeding the AQO are underlined.

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

3.2.1.3                The 19th highest 1-hour NO2 levels ranged from 51 to 58 μg/m3, which were within the AQO of 200μg/m3. No significant trend of 1-hour NO2 levels can be observed from Year 2015 to Year 2019. No exceedances were found in Year 2015 – Year 2019 annual NO2 concentrations, remaining at a low level of around 10 to 11μg/m3.

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

3.2.1.5                The 10th highest 8-hour O3 levels ranged from 169 to 212 μg/m3, all exceeding the AQOs of 160μg/m3. No trend is observed from the data from Year 2015 to Year 2019.

3.2.1.6                The 10th highest daily RSP levels had generally decreased from 86 μg/m3 in 2015 to 64 μg/m3 in 2019. The annual RSP levels also exhibited a downward trend from 35 μg/m3 in 2015 to 31 μg/m3 in 2019, which were all within the AQO of 50μg/m3.

3.2.1.7                The 10th highest daily FSP levels had generally decreased from 66 μg/m3 in 2015 to 35 μg/m3 in 2019, as compared with the AQO of 75μg/m3. The annual FSP levels also exhibited a downward trend from 24 μg/m3 in 2015 to 17 μg/m3 in 2019, which were all within the AQO of 35μg/m3.

3.2.2                    Future Ambient Air Quality Conditions

3.2.2.1                It should be noted that the ambient air quality conditions described in the above sections are historical data in the last 5 years. During the 16th Hong Kong-Guangdong Joint Working Group Meeting on Sustainable Development and Environmental Protection (January 2017), the Hong Kong and Guangdong Governments jointly endorsed a Work Plan and will continue to implement the Pearl River Delta (PRD) Regional Air Quality Management Plan up to year 2020. Key emission reduction measures to be implemented by Hong Kong and Pearl River Delta Economic Zone (PRDEZ) include:

Hong Kong Government

·              Tightening of vehicle emission standards;

·              Phasing out highly polluting commercial diesel vehicles;

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

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

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

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

·               Controlling emissions from off-road vehicles/equipment;

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

·               Controlling Volatile Organic Carbon (VOC) contents of solvents used in printing and construction industry.

Pearl River Delta Economic Zone

·         Installing desulphurization and denitrification systems at large-scale coal-fired power generating units;

·         Closing down small-scale power generating units;

·         Phasing out heavily polluting cement plants as well as iron and steel plants;

·         Installing vapour recovery systems at petrol filling stations, oil depots and on tanker trucks;

·         Implementing new pollutant emission standards for boilers as well as specific industries such as cement, furniture manufacturing, printing, shoe-making and surface coating (automobile manufacturing) industries;

·         Installing denitrification systems at new dry-type cement kilns;

·         Tightening the emission standards for newly registered petrol vehicles to Guangdong IV standard; and

·         Progressively supplying diesel at National IV standard and petrol at Guangdong IV standard.

3.2.2.2                In order to predict the future ambient air quality taking into account the measures to improve air quality, PATH-2016 (Pollutants in the Atmosphere and their Transport over Hong Kong), a regional air quality model, has been developed by EPD to simulate air quality over Hong Kong against the PRD as background.

3.2.2.3                The Project involves 1 grid in the PATH-2016. The hourly pollutant concentration data predicted by PATH-2016 for year 2020 are provided by EPD and are summarised in Table 3.3. Figure 3.1 illustrates the locations of concerned PATH grids for the assessment area.

Table 3.3         Future ambient air quality for concerned PATH grids (Year 2020)

Pollutant

Parameter

Predicted Concentrations (μg/m3)

AQOs [1] (μg/m3)

49_56

SO2

4th highest 10-min [3]

143

500 (3)

4th highest 24-hour

27

125 (3)

NO2

19th highest 1-hour

65

200 (18)

Annual

9

40 (N.A[4])

CO

Max. 1-hour

1,023

30,000 (0)

Max. 8-hour

833

10,000 (0)

O3

10th highest 8-hour

154

160 (9)

RSP

10th highest 24-hour

68

100 (9)

Annual

31

50 (N.A[4])

FSP

10th highest 24-hour[2]

51

75 (9)

Annual[2]

22

35 (N.A[4])

Notes:

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

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

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

[4]     N.A – Not Applicable.

3.3                         Assessment Area and Air Sensitive Receivers

3.3.1                    Assessment Area

3.3.1.1                With reference to Clause 3.4.4.2 of the EIA Study Brief, the assessment area for air quality impact assessment should be defined by 500m from boundary of the Project and the works of the Project, which shall be extended to include major existing, committed and planned air pollutant emission sources identified to have a bearing on the environmental acceptability of the Project. A 500m assessment area from the boundary of the Project and its associated works area has been adopted.  Figure 3.1 shows the extent of the assessment area and the location of the Project.

3.3.2                    Air Sensitive Receivers

3.3.2.1                In accordance with Annex 12 of the TM-EIAO, Air Sensitive Receivers (ASRs) include any domestic premises, hotel, hostel, hospital, clinic, nursery, temporary housing accommodation, school, educational institution, office, factory, shop, shopping centre, place of public worship, library, court of law, sports stadium or performing arts centre.

3.3.2.2                However, for other premises which are not stipulated above, including open space, farm land, and recreational uses (e.g. park, playground, basketball court, football field, etc.), reference shall be made to Clause 2.2, Annex 12 of the TM-EIAO, which stated that any other premises or place with which, in terms of duration or number of people affected, has a similar sensitivity to the air pollutants as the abovementioned premises and places are also considered as a sensitive receiver.

3.3.2.3                Representative Air Sensitive Receivers (ASRs) within 500m assessment area were identified. Existing ASRs were identified by means of reviewing topographic maps, aerial photos and land status plans, supplemented by site inspections. Besides, relevant Outline Zoning Plans (OZP), Outline Development Plans, Layout Plans and other published plans in the vicinity of the Project have been reviewed.

3.3.2.4                Representative ASRs within the assessment area are shown in Figure 3.1 and summarised in Table 3.4. They are mainly village houses and a temple. Besides, the nearest ASR is the planned Geoheritage-cum-ecological Education Centre at 340m from the Project boundary.

Table 3.4         Representative Air Sensitive Receivers at Lai Chi Wo Pier

ASR

Description

Uses[1]

ASR Height (metre above Ground)

Approx. Separation Distance

LCW-A1

Hip Tin Temple & Hok Shan Monastery

W

1.5

360m

LCW-A2

Lai Chi Wo Village

R/H [2]

1.5, 5, 10

400m

LCW-A3

Planned Geoheritage-cum-ecological Education Centre

G/IC

1.5

340m

Notes:

[1]       R – Residential; W – Public Place of Worship; H – Hotel; G/IC – Government, Institution and Community

[2]       The proposed hotel use (Planning Application No. A/NE-LCW/2) is located within Lai Chi Wo

3.4                         Construction Air Quality Impact Assessment

3.4.1                    Identification of Pollutants of Concern

3.4.1.1                According to Section 13.2.4.3 of USEPA Compilation of Air Pollutant Emissions Factors (AP-42), amongst all aerodynamic particle sizes (i.e. TSP), there are 47% of particles with an aerodynamic diameter of <10 μm (i.e. RSP). Hence, TSP and RSP are the most representative pollutants for construction phase assessment. However, upon the effect of the AQOs from 1st January 2014, FSP has been included as one of the criteria pollutants in the AQOs. As a conservative approach, FSP has also been assessed, notwithstanding that it only constitutes 7% of the total particles in fugitive dust.

3.4.1.2                As discussed in Section 2, most of the construction works required are marine-based and only very limited land-based construction activities would be required. Besides, there would not be any stockpiling on land. Any spoil generated will be temporary stored on the barges and will be transported away on a regular basis.

3.4.1.3                In addition, marine vessels will still be required for the commuting of site personnel and the delivery of goods back and forth the Project site. Besides, Power Mechanical Equipment (PME) such as generator, crane and piling machineries would be required for the construction of the proposed pier and the temporary pier, and the demolition work of the temporary pier.

3.4.1.4                Fuel combustion from the use of PME during construction works as well as the engines and generator sets on vessels from the induced marine traffic could be emission sources of Nitrogen Dioxide (NO2), Sulphur Dioxide (SO2) and Carbon Monoxide (CO), and thus are considered as pollutants of concern. However, the engines of barges will be throttled down after mooring and limited emissions are expected.

3.4.1.5                In addition, there is neither source of Lead (Pb) nor Ozone (O3) during the construction of the Project. Hence, Pb and O3 are not considered as the key pollutants for assessment.

3.4.1.6                Besides, the Project itself is not a source of odour and will not arise any potential odour impact to the representative ASRs during the construction phase. Further odour assessment is not required.

3.4.2                    Identification of Pollution Sources and Emission Inventory

3.4.2.1                As discussed in Section 1, the major works items for the Project include the following:

·               Carrying out site investigation works for detailed design;

·               Provision of plants, equipment and materials on working barge(s) for implementation of the Project;

·               Provision of temporary berthing and mooring facilities (temporary pier) using working barge and/or steel structures supported by piles to maintain access to Lai Chi Wo throughout the construction stage;

·               Installation of piles for the new pier;

·               Modification of the existing pier and construction of new pier structures (e.g. installation of precast elements of the pier structure etc.);

·               Construction of associated facilities on the new pier; and

·               Removal of temporary pier after completion of the improvement works on the existing pier.

3.4.2.2                The key air pollution sources in association with the Project that may bear upon the air quality including dust emission from the following construction activities:

·               Above-water construction / demolition activities;

·               Material handling; and

·               Wind erosion of stockpiling areas on the working barge(s).

3.4.2.3                For the fuel combustion from the use of PME, a plant inventory for major construction activities are given in Appendix 4.2. As for the vessels for the commuting of site personnel and the delivery of goods back and forth the Project site, it is expected there would be three to four round trips per working day.

3.4.2.4                There would not be any chimneys from the Project. By site inspection, neither chimneys nor other industrial emissions are identified in the assessment area. There is also no concurrent project in the vicinity of the Project.

3.4.3                    Evaluation of Construction Air Quality Impact

Air Quality Impact – Site Investigation Works for Detailed Design

3.4.3.1                Site investigation works for detailed design of the Project are tentatively targeted to commence in mid-2021 for completion in end-2021. As the works are mostly below water, there are neither exposed workfronts nor heavy construction works which may have dust emission. Furthermore, only one/two small jack-up barge(s) will be deployed to carry out the works, and limited number of boat trips will be generated per day to transport workers to and from the nearest pier in other district and the Project site. Thus, marine emission is limited.

Construction Dust Impact – Pier Improvement Works

3.4.3.2                The pier improvement works of the Project is tentatively targeted to commence in Year 2023 for completion in Year 2025. Since the foundation works are mostly below water, there are neither exposed workfronts nor heavy construction works which may have dust emissions. Hence, fugitive dust emissions from its construction are anticipated to be limited. Moreover, adoption of prefabricated elements for above-water superstructures (e.g. piled deck and canopy cover as far as practicable) manufactured off-site at Contractor’s factory would reduce the amount of dust generation on-site, as it requires limited construction plant and raw materials to be stockpiled on the barges. Stockpiles on the barges would be properly covered by impervious materials or sheltered to avoid fugitive dust emission by wind erosion.

3.4.3.3                For the removal of temporary berthing and mooring facilities, the prefabricated steel-made temporary pier deck structures will be uninstalled and transported off site. As the deck structures of the temporary pier will be constructed by bolt-and-nut and welding methods as far as practicable, such structures will be readily uninstalled without heavy construction during the demolition stage.  For the temporary pile foundation removal work, they will be cut by wire saws or similar as close to the seabed as possible. As the works are carried out under water, fugitive dust emissions are not anticipated. Overall, the demolition works are relatively small and transient, and hence fugitive dust emissions are limited.

3.4.3.4                Sea transportation would be used to deliver and dispose of the waste generated to the designated disposal outlets. As discussed in Section 6.3.6, the transportation routes of marine vessels will mainly pass through the Crooked Harbour towards the Mirs Bay, which are away from the coastal sensitive receivers. In addition, due to small output of waste of the Project, there will only be a maximum of 2 trips of vessel per working day for waste transportation during the construction phase (for period between 0800 and 1700 hours). Waste and fill materials will be properly contained or covered to avoid potential dust and odour impacts. Nuisance from the delivery of waste from the Project is not anticipated.

3.4.3.5                The trip frequency of marine transportation for the commuting of site personnel and the delivery of goods per day are limited. In the absence of vehicular emission, chimneys and industrial emission sources, and concurrent projects within the assessment area, adverse dust emission by other emissions sources is not anticipated. Moreover, the ASRs as shown in Table 3.4 would be located at least around 340m away from the Project site. Based on the predicted results from PATH-2016 model in Table 3.3, the predicted 10th Highest 24-hour RSP and FSP are about 68% of the corresponding HKAQOs, whilst the predicted annual RSP and FSP are about 62% of the corresponding HKAQOs. Given the large separation between the Project site and the ASRs and limited dust emission from the works, adverse construction dust impacts are not anticipated at the ASRs. In the absence of other major emission sources in the assessment area, non-compliance of HKAQOs/ TM-EIAO is not anticipated.

3.4.3.6                In addition, the recommended good site management practices as stipulated in the Air Pollution Control (Construction Dust) Regulation and mitigation measures (e.g. regular watering etc.) will be implemented to minimise any potential construction dust impact.

Air Quality Impact from Fuel Combustion

3.4.3.7                The combustion of fuel by PME is an emission source. To improve air quality and protect public health, the Air Pollution Control (Fuel Restriction) Regulations was enacted in 1990 and amended in 2008, to impose legal control on the type of fuels allowed for use and their sulphur contents in commercial and industrial processes to reduce SO2 emission. To control the SO2 emission, the liquid fuel with a sulphur content of less than 0.005% by weight is permitted to be used in this regulation. In addition, the Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation, which came in effect on 1 June 2015, regulates emissions from machines and non-road vehicles. Starting from 1  December 2015, only approved or exempted non-road mobile machinery is allowed to be used in construction sites. Hence, with the effect of the Regulation, the emissions from PME are considered relatively small. Furthermore, the Project would only involve small scale works. Most of the structures of the pier will be constructed by prefabrication method. Extensive use of Non-road Mobile Machineries (NRMM) is not anticipated. In this regard, the number of NRMM that would be used would be limited as well (i.e. a tug boat, a derrick barge, 2 sets of drill rigs and a generator set), details of NRMM can be referred to the plant inventory in Appendix 4.2. Hence, emissions from PME would be considered relatively small and adverse impact is considered unlikely.

3.4.3.8                In view of the lack of road network at Lai Chi Wo, the only access to Lai Chi Wo is via marine transportation. It would be the only means to deliver and dispose of materials to and from the Project site to designated disposal outlets.

3.4.3.9                For the generated marine traffic for the commuting of site personnel and the delivery of goods back and forth the Project site, three to four round trips are anticipated on each working day. The fuel to be used by vessels shall comply with the requirements of Air Pollution Control (Marine Light Diesel) Regulation and Air Pollution Control (Fuel for Vessels) Regulation that sulphur content in the fuel should not exceed 0.05% m/m. As the trip frequency is limited to three to four round trips per day, and the vessels will be throttled down or shut down when they arrive at the Project site, adverse air quality impact from the marine emissions is not anticipated. The delivery route shall also be as far away from the identified ASRs as practicable to minimise the air quality impact.

3.4.3.10            Based on the predicted results from PATH-2016 model in Table 3.3, the predicted 4th highest 10-minute and 4th highest 24-hour SO2 are about 29% and 22% of the corresponding HKAQOs respectively. The predicted 19th highest 1-hour and annual NO2 are about 33% and 23% of the corresponding HKAQOs respectively. The predicted maximum 1-hour and maximum 8-hour CO are about 3% and 8% of the corresponding HKAQOs respectively. All SO2, NO2 and CO concentration are at very low level in the ambient environment of the assessment area.

3.4.3.11            The ASRs as shown in Table 3.4 would be located at least around 340m away from the Project site. Given the large separation between the Project site and the ASRs and sufficient buffering capacity of SO2, NO2 and CO in the environment, adverse construction air quality impacts are not anticipated at the ASRs.

3.4.4                    Control Measures and Good Practices

3.4.4.1                Although no adverse impact in dust emission from the Project is anticipated, control measures and good practices are still recommended for protecting the environment as far as practicable. In order to reduce the possible dust emission from the Project, the Contractor shall follow the procedures and requirements given in the Air Pollution Control (Construction Dust) Regulation. The following dust suppression measures/ practices should be incorporated by the Contractor to control the dust nuisance throughout the construction phase:

·               Spray water regularly as required at the surrounding pier area, access and working barges;

·               Cover or shelter any stockpile of dusty materials on working barges; and

·               Cover any dusty load on the barges by impervious sheeting during delivery and before they leave the site

3.4.4.2                To minimise air quality impact from fuel combustion, PME used in the construction site should be registered under Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation with the NRMM label displayed at a conspicuous position of the registered item. In addition, routing of barges used for delivery of goods should be as far away from the identified ASRs as practicable.

3.4.4.3                The Contractor is also advised to minimise the number of boat trips as far as practicable by appropriate planning to maximise the utilisation of each trip traveling to and from the nearest pier in other district and the Project site.

3.4.4.4                With the implementation of these control measures and good practices during construction phase of the Project and in the absence of other major emission sources in the assessment area, non-compliance of HKAQOs/ TM-EIAO is not anticipated.

3.4.5                    Cumulative Impact

3.4.5.1                In the absence of vehicular emission, chimneys and industrial emission sources, and concurrent projects within the assessment area and the trip frequency of marine transportation for the commuting of site personnel and the delivery of goods per day are limited, adverse dust emission and gaseous emission by other emissions sources is not anticipated As such, adverse cumulative air quality impact during the construction of the Project is not anticipated.

3.4.6                    Evaluation of Residual Air Quality Impact

3.4.6.1                With the implementation of the control measures and good practices as stipulated in the Air Pollution Control (Construction Dust) Regulation and the requirements in the Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation, Air Pollution Control (Marine Light Diesel) Regulation and Air Pollution Control (Fuel for Vessels) Regulation during construction phase of the Project, no adverse construction dust and gaseous emission impact is anticipated. Hence, no adverse residual air quality impact is anticipated during the construction phase.

3.5                         Operational Air Quality Impact Assessment

3.5.1                    Identification of Pollutants of Concern

3.5.1.1                During the operational phase of the Project, the improved pier itself would not have any emission sources such as generator sets. The major emissions are associated with the Kaito vessels, which emit SO2, NOx and CO during the fuel combustion process. Thus, SO2, NO2 and CO are the major pollutants of concern. Vessels may also have RSP and FSP emissions. However, the emission is comparatively minor, and they are not regarded as pollutants of concern.

3.5.1.2                In addition, there is neither source of Lead (Pb) nor Ozone (O3) during the operation phase of the Project. Hence, Pb and O3 are not considered as the key pollutants for assessment.

3.5.1.3                Besides, the Project itself is not a source of odour and will not arise any potential odour impact to the representative ASRs during the operational phase. Further odour assessment is not required.

3.5.2                    Identification of Pollution Sources and Emission Inventory

3.5.2.1                The Project itself does not intend to increase Kaito services. No additional air pollution sources would be added due to the implementation of the Project. Conversely, the main objectives of the Project are to enhance pier facilities and provide adequate structural integrity for safe pier usage.

3.5.2.2                There would not be any chimneys from the Project. By site inspection, neither chimneys nor other industrial emissions are identified in the assessment area. There are also no concurrent projects in the vicinity of the Project.

3.5.3                    Evaluation of Operational Air Quality Impact

3.5.3.1                In the absence of vehicular emission, chimneys and industrial emission sources, and concurrent projects within the assessment area, adverse dust emission and gaseous emission by other emissions sources is not anticipated. The representative ASRs, as summarised in Table 3.4, are located to the south of the Project site and are at least 340m away. As the pier length will increase from 64m to 155m with the landing steps shifted seawards, the proposed berthing locations associated with the marine traffic emissions will be farther away from the coast and the ASRs as compared with the current condition without pier improvement. Hence, the ASRs may result in a slight improvement of air quality. In the absence of other major emission sources in the assessment area, no non-compliance of HKAQOs/ TM-EIAO is likely to be anticipated during the operational phase of the Project.

3.5.4                    Mitigation Measures

3.5.4.1                As the Project would not generate or induce any additional air quality impact, mitigation measures are considered not necessary.

3.5.5                    Cumulative Impact

3.5.5.1                In the absence of vehicular emission, chimneys and industrial emission sources, and concurrent projects within the assessment area, adverse dust emission and gaseous emission by other emissions sources is not anticipated. As such, adverse cumulative air quality impact during the operation of the Project is not anticipated.

3.5.6                    Evaluation of Residual Air Quality Impact

3.5.6.1                As the Project would not generate or induce any additional air quality impact, it is anticipated that there would be no adverse residual air quality impact during the operational phase.

3.6                         Conclusion

3.6.1                    Construction Phase

3.6.1.1                The key air pollution sources in association with the Project have been identified and the potential construction dust impact has been evaluated. During construction, since the site investigation and foundation works are mostly below water, there are neither exposed workfronts nor heavy construction works which may have dust emissions. Hence, fugitive dust emissions from its construction are anticipated to be limited. Prefabrication method would be adopted for the construction of the superstructures as much as practicable to further minimise the construction dust impact on-site. Although there is no adverse impact to the identified ASRs, dust control measures and good practices in accordance with Air Pollution Control (Construction Dust) Regulation would be followed to avoid the potential dust impact.

3.6.1.2                As the scale of construction works is relatively small, extensive use of the PME is not required. Emissions from PME are therefore considered relatively small. Adverse cumulative impact is considered unlikely. Given that the trip frequency of marine transportation for the commuting of site personnel and the delivery of goods per day would be limited and the vessels will be throttled down when they arrive at the Project site, adverse air quality impact from the marine emissions is not anticipated.

3.6.2                    Operational Phase

3.6.2.1                The Project itself does not intend to increase Kaito services. No additional air pollution sources would be introduced due to the implementation of the Project. Conversely, the main objectives of the Project are to enhance pier facilities and provide adequate structural integrity for safe pier usage. As the Project would increase the separation distance between the ASRs and the vessels, the ASRs would result in a slight improvement of air quality. Therefore, adverse air quality impact during the operation phase of the Project is not anticipated.

3.7                         References

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

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

                    Environmental Protection Department (2017), Air Quality in Hong Kong 2015 http://www.aqhi.gov.hk/api_history/english/report/files/AQR2017e_final.pdf)