4.1.1. This section identifies potential impacts on air quality that may arise from the construction and operation of the proposed Project. The construction dust impact and operational air quality impact from the proposed Project were assessed. Where necessary, appropriate mitigation measures have been recommended to reduce the impacts from the proposed Project at the air sensitive receivers (ASRs) to satisfy the related environmental ordinances, legislation, standards and guidelines.
4.2.1. The establishment of the air quality impact assessment criteria of this EIA study was made in accordance with the Environmental Impact Assessment Ordinance (EIAO) (Cap. 499), Air Pollution Control Ordinance (APCO) (Cap. 311), Air Pollution Control (Construction Dust) Regulation, Hong Kong Planning Standards and Guidelines (HKPSG), Annexes 4 and 12 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM) as well as the requirements given in clause 3.4.3 and Appendix A of the EIA Study Brief (No. ESB-267/2014) issued in March 2014.
Hong Kong Planning Standards and Guidelines
4.2.2. The APCO provides regulatory framework on controlling air pollutants from a variety of stationary and mobile sources and encompasses a number of Air Quality Objectives (AQOs). Moreover, the Government’s overall policy objectives for air pollution are laid down in Chapter 9 of the 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.
Air Pollution Control Ordinance: Air Quality Objectives
4.2.3. The AQOs stipulate the concentrations for a range of air pollutants, namely sulphur dioxide (SO2), respirable suspended particulates (PM10), fine suspended particulates (PM2.5), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO), and lead (Pb). The AQOs are summarised in Table 4.1.
Table 4.1 Hong Kong Air Quality Objectives
|
Pollutant |
Concentration Limit, µg/m3 [1] (Number of Exceedances per Calendar Year Allowed in Brackets) |
||||
|
10-minute |
1-hour |
8-hour |
24-hour |
Annual |
|
|
Sulphur dioxide (SO2) |
500 (3) |
125 (3) |
|
||
|
Respirable suspended
particulates (PM10) [2] |
|
|
|
100 (9) |
50 (N/A) |
|
Fine suspended particulates (PM2.5) [3] |
|
|
|
75 (9) |
35 (N/A) |
|
Nitrogen dioxide (NO2) |
|
200 (18) |
|
|
40 (N/A) |
|
Ozone
(O3) |
|
|
160 (9) |
|
|
|
Carbon monoxide (CO) |
|
30,000 (0) |
10,000 (0) |
|
|
|
Lead (Pb) |
|
|
|
|
0.5 (N/A) |
[1] All measurements of the
concentration of gaseous air pollutants, i.e., SO2, NO2, O3
and CO, are to be adjusted to a reference temperature of 293 K (20oC) and a reference pressure of 101.325 kPa (one atmosphere). Meanwhile, “N/A”
represents not applicable since there is no AQO for such parameter.
[2] PM10 means the suspended
particulates in air with a nominal aerodynamic diameter of 10 µm or smaller.
[3] PM2.5 means the suspended
particulates in air with a nominal aerodynamic diameter of 2.5 µm or smaller.
Environmental Impact Assessment Ordinance: Technical Memorandum on Environmental Impact Assessment Process
4.2.4. The criteria and guidelines for evaluating air quality impacts are set out in Section 1 of Annex 4 and Sections 1 to 3 of Annex 12 respectively of the EIAO-TM. Annex 4 of the EIAO-TM stipulates that the 1-hour total suspended particular (TSP) level should not exceed 500 μg/m3 measured at 298 K (25 oC) and 101.325 kPa (one atmosphere) for the construction dust impact assessment. Annex 12 describes the guidelines on conducting air quality assessment, including determination of ASR, identification of emission characteristics and impact prediction and assessment etc.
Air Pollution Control (Construction Dust) Regulation
4.2.5. Mitigation measures for construction sites are specified in the Air Pollution Control (Construction Dust) Regulation. Notifiable and regulatory works are, also, under the control of this Regulation, in which appropriate dust control and suppression measures should be duly provided.
4.2.5.1. Notifiable works under the Air Pollution Control (Construction Dust) Regulation include:
· Site formation;
· Reclamation;
· Demolition of a building;
· Work carried out in any part of a tunnel that is within 100 m of any exit to the open air;
· Construction of the foundation of a building;
· Construction of the superstructure of a building; and
· Road construction work.
4.2.6. Regulatory works include:
· Renovation carried out on the outer surface of the external wall or the upper surface of the roof of a building;
· Road opening or resurfacing work;
· Slope stabilisation work; and
· Any work involving any of the following activities:
– Stockpiling of dusty materials;
– Loading, unloading or transfer of dusty materials;
– Transfer of dusty materials using a belt conveyor system;
– Use of vehicles;
– Pneumatic or power-driven drilling, cutting and polishing;
– Debris handling;
– Excavation or earth moving;
– Concrete production;
– Site clearance; and
– Blasting.
4.2.7. The proposed Project will include site formation, excavation and filling, foundation and construction of the main building, and is therefore notifiable. It will also include stockpiling of dusty materials, loading, unloading or transfer of dusty materials, use of vehicles, pneumatic or power-driven drilling, cutting and polishing, debris handling and site clearance, and is therefore regulatory.
4.2.8. In accordance with Section 1 of Annex 4 of the EIAO-TM, the limit of 5 odour units (OU) based on an averaging time of 5 seconds for odour prediction assessment should not be exceeded at any ASRs.
4.2.9. Pertaining to Section 3.3.9 of Chapter 9 of HKPSG, some small scale community uses (i.e. crematoria, livestock yards, stock wagon washing areas and wholesale fishes and poultry markets) can cause significant air pollution nuisance, primarily due to odour. Wherever practicable, these uses should be sited away from the main urban centres. Usually a buffer distance of at least 200m from nearby sensitive uses is required. Acceptable uses in the buffer area include industrial areas, godowns, cold storages, carparks and amenity areas. Use as an open space may also be tolerated.
4.2.10. In the proximity of the proposed Project, no odour-generating activity was identified. Nevertheless, odour emission due to the refuse collection vehicles (RCVs) of the proposed Project was evaluated and will be presented in the later sections.
Air Quality Criterion for Non-criteria Pollutants
4.2.11. Various organic or inorganic chemicals such as chloroethane, chloroform, hexachlorobenzene, arsenic, beryllium etc. would be released during the laboratory testing and operation of the GL Specialist Laboratory. In view of the absence of local statutory guidelines for non-criteria pollutants, the criteria available from international recognisable organisations are adopted in this study.
Other Environmental Guidelines Related to Air Quality
4.2.12. Other environmental guidelines and technical circulars published by the EPD which are of relevance to the study include:
· Guidelines on Assessing the 'TOTAL' Air Quality Impacts;
· Guidelines on Choice of Models and Model Parameters;
· Guidelines on Estimating Height Restriction and Position of Fresh Air Intake Using Gaussian Plume Models;
· Guidelines on the Estimation of 10-minute Average SO2 Concentration for Air Quality Assessment in Hong Kong;
· Guidelines on the Estimation of PM2.5 for Air Quality Assessment in Hong Kong; and
· Guidelines on the Use of Alternative Computer Models in Air Quality Assessment.
4.3.1. The proposed Project is planned to be constructed on area piece of land which is currently allocated as a works and staging area by DSD. It is surrounded by Sheung Tat Street to the northwest, Sheung Mau Street to the southwest and Sheung On Street to the southeast. The Project site is zoned “G/IC(2)”, whilst the surrounding areas are predominately zoned “Industrial”, “G/IC” and “Open Space”. As shown in Figure 1.1, developments in the vicinity of the site are identified and summarised in Section 3.1.2.
4.3.2. Dominant air pollution sources include the road traffic emissions mainly from Shing Tai Road, Island Eastern Corridor (IEC) and Wing Tai Road Flyover and to a lesser extent from Sheung On Street, Sheung Tat Street and Sheung Mau Street.
4.3.3. There is no fixed air quality monitoring station close to the Project site. The nearest EPD air quality monitoring station (AQMS) with similar characteristics to the study area is the Eastern AQMS at Sai Wan Ho Fire Station at 20 Wai Hang Street, Sai Wan Ho. Its latest 5 years of air quality data, i.e. 2009 to 2013, are summarised in Table 4.2 to depict the trend of the localised air quality.
Table 4.2 Background Air Quality at Eastern Air Quality Monitoring Station
|
Pollutant |
5-year Annual Average Concentration 2009-2013 (µg/m3)[1] |
Annual AQO (µg/m3)[2] |
|
SO2 |
8.4 |
N/A |
|
PM10 |
42.0 |
50 |
|
PM2.5[3] |
27.7 |
35 |
|
NO2 |
57.4 |
40 |
|
O3 |
42.0 |
N/A |
[1]
Monitoring result(s) exceeding the AQO is/are underlined.
[2]
“N/A” represents not applicable since there is no AQO for such parameter.
[3]
Measured concentration is only available between 2011 and 2013.
4.4.1. As stated in clause 3.4.3 of the EIA Study Brief, the study area for the air quality impact assessment should be defined by a distance of 500 m from the boundary of the Project site. ASRs were identified in accordance with Annex 12 of the EIAO-TM, including any domestic premises, hotels, hostels, hospitals, medical clinics, nurseries, temporary housing accommodation, schools, educational institutions, offices, factories, shops, shopping centres, places of public worship, libraries, courts of law, sports stadiums, performing arts centres or any recreational facilities. Assessment points of the identified ASRs were carefully selected in order to represent the worst impact point of these ASRs.
4.4.2. The existing ASRs were identified with reference to the latest best available information at the time of preparation of this report, like those showing on the survey maps, topographic maps, aerial photos and other relevant published land use plans. Various site surveys were conducted to verify the sensitive receivers and confirm with the desktop studies.
4.4.3. The existing ASRs include those at Knight Court, Hang Fa Tsuen, Tsui Wan Estate, the Hong Kong Institute of Vocational Education (Chai Wan) and Pamela Youde Nethersole Eastern Hospital etc.
4.4.4. The committed / planned ASRs were identified with reference to the latest best available information at the time of preparation of this study, which include those earmarked on the approved Chai Wan OZP (No. S/H20/21), and other relevant published land use plans, including plans and drawings published by the Lands Department and any land use and development applications approved by the Town Planning Board.
4.4.5. The committed / planned ASRs, such as a planned pet garden at Sheung On Street and a planned THEi New Campus were identified. Details of the representative existing and planned ASRs are shown in Figure 4.1 and summarised in Table 4.3. The photos taken during the site visit on 20 May 2014 is presented in Appendix 4.1.
Table 4.3 Representative Air Sensitive Receivers
|
ASR ID |
Description |
Approx. Horizontal Distance to Project Site (m) |
Approx. Building Height (m) |
Existing (E) or
Planned (P) |
Land Use |
|
ASR 1 |
Metro Recreational Club Chai Wan Depot Club House
(MTR Facilities) |
210 |
6 |
E |
Recreational |
|
ASR 2 |
Heng Fa Chuen Lutheran Day Nursery |
435 |
6 |
E |
Educational |
|
ASR 3 |
Heng Fa Chuen Block 1 |
465 |
48 |
E |
Residential |
|
ASR 4 |
Heng Fa Chuen Block 50 |
300 |
66 |
E |
Residential |
|
ASR 5 |
Heng Fa Chuen Playground |
215 |
- |
E |
Recreational |
|
ASR 6 |
Government Logistics Centre |
135 |
48 |
E |
Government |
|
ASR 7 |
NWFB Depot |
50 |
40 |
E |
Industrial |
|
ASR 8 |
Hong Kong Institute of Vocational Education (Chai
Wan) - Academic Block |
145 |
18 |
E |
Educational |
|
ASR 9 |
Knight Court Flat A & B |
180 |
72 |
E |
Residential |
|
ASR 10 |
Knight Court Flat C & D |
160 |
72 |
E |
Residential |
|
ASR 11 |
Citybus Depot |
55 |
12 |
E |
Industrial |
|
ASR 12 |
EMSD Workshop |
190 |
- |
E |
Industrial |
|
ASR 13 |
Wing Tai Road Garden |
295 |
- |
E |
Recreational |
|
ASR 14 |
Pamela Youde Nethersole Eastern Hospital - Block F |
430 |
66 |
E |
Community |
|
ASR 15 |
Pamela Youde Nethersole Eastern Hospital - East
Block |
440 |
27 |
E |
Community |
|
ASR 16 |
Tsui Wan Estate Playground |
340 |
- |
E |
Recreational |
|
ASR 17 |
Tsui Shou House, Tsui Wan Estate |
345 |
93 |
E |
Residential |
|
ASR 18 |
Endeavourers Chan Cheng Kit Wan Kindergarten |
340 |
3 |
E |
Educational |
|
ASR 19 |
Tsui Ching House, Hang Tsui Court |
410 |
75 |
E |
Residential |
|
ASR 20 |
Tsui Wan Nursing Home Limited |
400 |
3 |
E |
Community |
|
ASR 21 |
Tsui Wan Estate Shopping Complex |
425 |
9 |
E |
Commercial |
|
ASR 22 |
S.K.H Li Fook Hing Secondary School |
455 |
18 |
E |
Educational |
|
ASR 23 |
TWGHs & LKWFSL Mrs Fung Yiu Hing Memorial
Primary School |
455 |
18 |
E |
Educational |
|
ASR 24 |
Chai Wan Fire Station |
440 |
15 |
E |
Government |
|
ASR 25 |
Chai Wan Industrial City Phase II |
300 |
71 |
E |
Industrial |
|
ASR 26 |
Ming Pao Industrial Centre Block B |
390 |
84 |
E |
Industrial |
|
ASR 27 |
Safety Godown Industrial Building |
315 |
53 |
E |
Industrial |
|
ASR 29 |
Planned
Pet Garden at Sheung On Street |
255 |
- |
P |
Recreational |
|
ASR 30 |
Planned THEi
New Campus |
200 |
63 |
P |
Educational |
4.5.1. As mentioned in Section 2.3 of this EIA Report, no major earthworks will be required for site formation works for the proposed Project where construction of basement structure does not exist. Only minor excavation works would be anticipated for the construction of the concrete footing for the support of the building structure and the underground plumbing and drainage works. Since the amount of construction and demolition materials generated would be minimal, impacts from the transportation of dusty materials would be negligible. In addition, dust potentially generated as a result of the concreting works for the footing and concrete floor slab would be insignificant as the concrete will be pre-mixed and transferred to the Project site by concrete lorry mixers.
4.5.2. During operation of the proposed Project, potential sources to the surrounding would be air pollutant emissions from vehicular movement and idling vehicles with their started engines within the proposed Project. In addition, potential air quality impacts during the operation phase of the proposed Project would be dominated by the vehicular emissions from the nearby open roads.
4.5.3. Vehicular emission comprises a number of pollutants, including NOx, PM10, SO2, CO, Pb, TAPs etc. Motor vehicles are the main causes of high concentrations of NOx, PM10 and PM2.5 at street level in Hong Kong and are considered as key air quality pollutants for projects located at urbanised area. For other pollutants, due to the low concentration in vehicular emission, they are not considered as key pollutants for the purpose of this study.
Nitrogen Oxides (NOx)
4.5.4. NOx are the major pollutants from fossil fuel combustion. According to the “Environment Hong Kong 2013” published by EPD and Environment Bureau, road transport is the second largest NOx contributor which accounted for 29% of the total emission in Hong Kong in 2011. Increasing traffic flow would inevitably increase the NOx emission and subsequently the roadside NO2 concentration. Hence, NO2 is one of the key pollutants for the operational air quality impact assessment of the proposed Project. 1-hour and annual averaged NO2 concentrations at each representative ASRs would be assessed and compared with the local AQOs to determine the compliance.
Respirable Suspended Particulates (PM10)
4.5.5. PM10 refers to suspended particulates with a nominal aerodynamic diameter of 10μm or less. According to the “Environment Hong Kong 2013” published by EPD and Environment Bureau, road transport is the second largest PM10 contributor in 2011 which accounted for 19% of the total emission. Increasing traffic flow would inevitably increase the roadside PM10 concentration. Hence, PM10 is also one of the key pollutants for the operational air quality assessment of the proposed Project. 24-hour and annual averaged RSP concentrations at each representative ASRs would be assessed and compared with the local AQOs to determine the compliance.
Fine Suspended Particulates (PM2.5)
4.5.6. PM2.5 refers to suspended particulates with a nominal aerodynamic diameter of 2.5μm or less. PM2.5 is also a component of PM10. Given the importance of PM10 being a major air pollutant due to road traffic, increase in traffic volume would inevitably increases the roadside PM2.5 concentration. Hence, PM2.5 is also one of the key pollutants for the operational air quality assessment of the proposed Project. 24-hour and annual averaged FSP concentrations at each representative ASRs would be assessed and compared with the local AQOs to determine the compliance.
Sulphur Dioxide (SO2)
4.5.7. SO2 is formed primarily from the combustion of sulphur-containing fossil fuels. SO2 emission from vehicular exhaust is due to the sulphur content in diesel oil. According to EPD’s “Cleaning the Air at Street Level”, ultra low sulphur diesel (ULSD) with a sulphur content of only 0.005% has been adopted as the statutory minimum requirement for motor vehicle diesel since April 2002, which is 3 years ahead of the European Union. Given the use of ULSD, road transport is the smallest share of SO2 emission sources in 2011 and only constitutes <1% of the total SO2 emission, according to the information of the “Environment Hong Kong 2013” published by EPD and Environment Bureau. As from 1 July 2010, EPD has tightened the statutory motor vehicle diesel and unleaded petrol specifications to Euro V level, which further tightens the cap on sulphur content from 0.005% to 0.001%.
4.5.8. Road traffic therefore contributes to only a very small amount of SO2 emission, relatively low measured concentrations. With the adoption of low-sulphur and ultra-low-sulphur fuel under the existing Government policy, SO2 would not be a critical air pollutant of concern in the air impact assessment for road traffic.
Carbon Monoxide (CO)
4.5.9. CO is a typical pollutant emitted from fossil fuel combustion and comes mainly from vehicular emissions. With reference to the “Air Quality in Hong Kong 2012” issued by the EPD, the highest measured 1-hour average (3,810 μg/m3) and the highest 8-hour average (3,018 μg/m3) in 2012 were both recorded at the Causeway Bay roadside station; these values were around one eighth and one third of the respective AQOs limits. In view of the fact that there exists a huge margin to the AQOs, CO would not be a critical air pollutant of concern in this study.
Ozone (O3)
4.5.10. O3 is a secondary pollutant which is produced from photochemical reaction between NOx and volatile organic chemicals (VOCs) in the presence of sunlight, which will not be generated by any man-made activities/ sources. Concentration of O3 is governed by both precursors and atmospheric transport from other areas. When precursors transport along under favourable meteorological conditions and sunlight, O3 will be produced. This explains why higher O3 levels are generally not produced in the urban core or industrial area but rather at some distance downwind after photochemical reactions have taken place. In the presence of large amounts of NOx in the roadside environment, O3 reacts with nitrogen monoxide (NO) to give NO2 and then results in O3 removal. O3 is therefore not considered as a key air pollutant for the operational air quality assessment of the proposed Project.
Lead (Pb)
4.5.11. The sale of leaded petrol has been banned in Hong Kong since 1 April 1999. According to the “Air Quality in Hong Kong 2012”, the measured ambient lead concentrations of overall 3-month averages in 2012 range from 11 ng/m3 (Tung Chung) to 57 ng/m3 (Yuen Long). The measured concentrations were well below the AQOs limits. Therefore, lead is not considered as a critical air pollutant of concern.
Toxic Air Pollutants (TAPs)
4.5.12. TAPs, also known as hazardous air pollutants, refer to any airborne substances which may cause or have the potential to cause adverse health effects at anticipated ambient exposures. Since 1997, the EPD has started to monitor various TAPs and the monitoring data collected so far indicate that the levels of toxic air pollutants in Hong Kong are comparable to those observed in other major cities. TAPs due to the operation of the GL Specialist Laboratory would be discussed in later section and evaluate the level of impacts.
4.5.13. In short, 1-hour and annual concentrations of NO2 as well as 24-hour and annual concentrations of PM10 and PM2.5 would be simulated and calculated by appropriate air modelling softwares.
4.5.14. In order to assess the cumulative air quality impact, cumulative pollutant-emitting activities within the study area were reviewed in the air quality impact assessment, including:
· Road traffic emissions from all road links within the 500 m from the boundary of the Project site, including IEC, Wing Tai Road, Shing Tai Road, Sheung Mau Street and Sheung On Street etc.;
· Vehicular gaseous emissions within the proposed Project;
· Idling gaseous emissions within the proposed Project;
· Odour emissions within the proposed Project; and
· Volatile chemical emissions within the proposed Project.
4.6.1. There are several concurrent projects in the vicinity of the Project site, as summarised in Table 3.4. The list was based on the best available information received at the time of assessment and only those with implementation programme would be considered as concurrent projects for cumulative impacts. Potential cumulative impacts of various environmental aspects, if any, from the planned major concurrent projects, are assessed in the individual sections of this EIA study.
4.6.2. As aforementioned in Section 4.5.1 in this report, dust generated during construction of the proposed Project would be expected to be minimal. According to the reply from the Vocational Training Council, the construction works for the planned THEi New Campus at adjacent western boundary of the site would be anticipated to commence in around the third quarter of year 2013 and completed in around the third quarter of year 2016. Therefore, the construction of the proposed Project would have an overlapping with the planned THEi New Campus for a short period of time (probably only one to two months). With the implementation of sufficient dust suppression measures as stipulated under the Air Pollution Control (Construction Dust) Regulation and good site practices, significant dust generated from the construction of the planned developments is not anticipated. Hence, adverse cumulative dust impact during the construction phase of the proposed Project would not be anticipated.
4.6.3. For the concurrent projects during the operation phase of the proposed Project, vehicular emissions from the open road traffic are assessed by CALINE 4 to evaluate the air quality impact.
4.7.1. With the implementation of good site practices and sufficient dust suppression measures as stipulated under the Air Pollution Control (Construction Dust) Regulation, significant dust generation from the construction of the proposed Project is not anticipated. No adverse impact to the representative ASRs would be anticipated. Therefore, quantitative dust impact assessment has not yet been considered as required.
General Approach
4.7.2. The study area for this air quality impact assessment was defined by a distance of 500 m from the boundary of the Project site.
4.7.3. A regional air quality prediction model developed by the EPD, Pollutants in the Atmosphere and the Transport over Hong Kong (PATH), was used to quantify the background air quality levels in the study area. The closest PATH model year to the occupancy year of the proposed Project, i.e. 2020, was selected.
4.7.4. A near-field dispersion model was used, i.e. CALINE4, for line sources to quantify the air quality impacts at local scale from open road emission. Another near-field model ISCST3 was used to assess point and volume sources to quantify the air quality impacts at local scale from volume sources induced by the activities within the proposed Project.
4.7.5. The steps for the air quality modelling for operation phase started with formatting the traffic figures by survey and model projection. Secondly, the assessment year was determined using EMFAC-HK by finding out the maximum emission inventory of the modelled 3 years, i.e. 2018, 2023 and 2033. The calculated total vehicular tailpipe emission plus the traffic data were then used to establish the hourly emission factor for the open roads within the 500 m study area in the selected assessment year. With the aid of CALINE 4, air quality impacts due to NO2, PM10 and PM2.5 from open roads were predicted. On the other hand, the emissions from the proposed Project are assessed by ISCST3 for the same selected assessment year.
4.7.6. The cumulative concentrations of simulation results from CALINE 4 and ISCST 3, together with the PATH data in year 2020 at grid (33,25), (33,24), (34,25) and (34,24) as background concentrations, were predicted at the representative ASRs in this air quality assessment.
4.7.7. The overall methodology is illustrated below:
4.7.8.
Traffic data by survey and model
projection Establishment of emission inventory using EMFAC-HK Determination of assessment year by sensitivity test Background emission inventory from PATH in year 2020 CALINE 4 modelling for line sources ISCST 3 modelling for point/ area/ volume sources Cumulative air quality assessment Stability class calculated by PCARAMMET Meteorological data
As mentioned in Table
3.1, the operation hours of the proposed Project for different future
users are various, and dependent on their operation needs. The average daily in
and out traffic volumes will be about 365, where the breakdown of the hourly in
and out traffic volume has been verified with the HKPF, EMSD, FEHD and GL
respectively.
Meteorological Data from Hong Kong Observatory (HKO)
4.7.9. The meteorological characteristics of the nearest available HKO’s meteorological station(s) are found representative for the study area. Weather data for the year 2013 was adopted in the model. It is also confirmed that the data is at least 90% valid. Relevant information are summarised as below:
· Temperature: hourly record in 2013 from King’s Park Weather Station; and
· Relative humidity: hourly record in 2013 from King’s Park Weather Station.
4.7.10. Under the circumstance where wind speed is 1.0 m/s or less, wind speed was assumed to be a minimum of 1.0 m/s to represent the worst-case scenario in accordance with the Guidelines on Choice of Models and Model Parameters.
4.7.11. Wherever the hourly meteorological data is not available, the results of the related hours were not considered.
4.7.12. The annual average hourly values are arithmetic mean of the same hourly interval over the entire year. Useful data was selected to obtain the annual hourly average of temperature and relative humidity to generate the representative emission factor from EMFAC-HK. The adopted values are given in Appendix 4.2.
Meteorological Data from Mesoscale Model 5 (MM5) in PATH Model
4.7.13. MM5 meteorological data with a base year of 2010 directly extracted from the PATH model was used as input into the CALINE 4 and ISCST 3 models. Grid-specific composite meteorological data was adopted, including:
· Wind speed;
· Wind direction;
· Mixing height; and
· Temperature.
4.7.14. The hourly values for atmospheric stability class from meteorological surface observations was calculated by a separate model called PCARAMMET for the use in the CALINE 4 and ISCST 3 modelling.
4.7.15. The study area of the proposed Project covers grid (33, 25), (33, 24), (34, 25) and (34, 24) as appended in Figure 4.2. Raw MM5 meteorological data was extracted from these grids for the purpose of assessment.
4.7.16. The traffic data for this study was obtained from a traffic survey, historical trend, planning data and the road traffic induced by the proposed Project. The traffic forecast was prepared by the Traffic Consultant of the proposed Project for the years 2018, 2023 and 2033 and was endorsed by TD. Hourly forecast of weekday traffic flow, covering the 16 vehicle classes, on the major roads related to the proposed Project is summarised in Appendix 4.3. Such data was used for EMFAC-HK modelling to calculate the vehicular emission factors and also for subsequent for CALINE 4 modelling within the study area.
Determination of Assessment Year
4.7.17. The potential air pollution impacts for future road traffic were determined by the highest emission strength from the vehicles among the assessed operation years after the completion of construction of the proposed Project. Sensitivity tests were conducted to determine the worst-case scenario within 15 years after the occupancy of the proposed Project, namely 2018, 2023 and 2033.
4.7.18. Pertaining to the emission control scheme in the selected years, together with the varied vehicle miles travelled (VMT), sets of emission inventories with emission factors from EMFAC-HK were produced for each year. Emission inventories in the year having the highest emission inventories of NOx, PM10 and PM2.5 are used as the model year for the air quality impact assessment because it represents the worst-case scenario prediction associated with the vehicular gaseous emission.
Open Road Emission Model – CALINE 4
4.7.19. The modelling of impacts from open roads was undertaken using the CALINE 4 model. With the result data from EMFAC-HK, hourly emission rates of a particular road link, in terms of g/mile/hour were formulated by summing the product of the hourly emission rate of each vehicle class and the percentage of vehicle of that class. An example for the composite emission factor is as follows:
Emission factor = Σ(Emission rate)i × i%
=
4.7.20. In order to predict 1-hour, 24-hour and/or annual average of the pollutant levels, 8760 hourly meteorological data was taken into account in CALINE 4. Directional variability was calculated according to the stability class in PCRAMMET output file (Stability class A, standard deviation of wind direction (ƠA) = 22.5°; Stability class B, ƠB = 22.5°; Stability class C, ƠC = 17.5°; Stability class D, ƠD = 12.5°; Stability class E, ƠE = 7.5°; Stability class F, ƠF = 3.8°). Surface roughness factor of (z0/15 cm)0.2 was adopted where z0 is the surface roughness in unit of cm. Surface roughness of 370 cm was adopted in this study as it is dominantly an urbanised area.
4.7.21. In view of the constraints of CALINE 4 in modelling elevated roads higher than 10m, the road heights of elevated road sections in excess of 10 m high above local ground or water surface were set to 10m in the CALINE4 model as a worst-case assumption.
4.7.22. Ozone Limiting Method (OLM) was adopted for the conversion of NOx to NO2, using the predicted O3 level from SAQM data in PATH model. A tailpipe emission NO2/NOx ratio of 7.5% based on the EPD’s Guidelines on Choice of Models and Model Parameters has been assumed. The NO2/NOx conversion was calculated as follows:
[NO2]pred = 0.075 × [NOx]pred + MIN {0.925 × [NOx]pred, or (46/48) × [O3]bkgd}
where [NO2]pred is the predicted NO2 concentration
[NOx]pred is the predicted NOx concentration
MIN means the minimum of the two values within the brackets
[O3]bkgd is the representative O3 background concentration
(46/48) is the molecular weight of NO2 divided by the molecular weight of O3
4.7.23. The air quality impacts at 1.5m, 5m and 10m above local the ground level were modelled at the representative ASRs, due to the high rise buildings.
Fixed Exhaust Emission Model – ISCST 3
4.7.24. Hourly emission rates simulated by EMFAC-HK were used for the vehicular emission from travelling within the proposed Project. Other than that, emission rates due to the idling activities were made reference to the Road Tunnels: Vehicle Emissions and Air Demand for Ventilation published by the PIARC Technical Committee on Road Tunnel Operation in November 2004. Hourly NO2, PM2.5 and PM10 concentrations were then predicted and derived from ISCST 3 model.
4.7.25. In order to predict 1-hour, 24-hour and/or annual average of the pollutant levels, 8760 hourly meteorological data was taken into account in ISCST 3.
4.7.26. Surface roughness of 370cm was adopted in this study.
Determination of Vehicular Emissions from Open Roads
4.7.27. EMFAC-HK version 2.6.0 developed by the EPD was used to determine the emission factors of NOx, PM10 and PM2.5.
4.7.28. All vehicles travelling down the roads included in the assessment are categorised into 16 vehicle classes in accordance with Appendix I of EMFAC-HK Guideline on Modelling Vehicle Emissions which is shown in Table 4.4.
4.7.29. Details of vehicle classification for the proposed Project were incorporated in the methodology of the traffic forecast exercise.
Table 4.4 Vehicle Classification in EMFAC-HK
|
Index |
EMFAC-HK Code |
Description |
Gross Vehicle Weight (Tonnes) |
|
1 |
PC |
Private cars |
All |
|
3 |
Taxi |
Taxi |
All |
|
4 |
LGV3 |
Light goods vehicles ≤ 2.5 tonne |
≤ 2.5ton |
|
5 |
LGV4 |
Light goods vehicles >2.5-3.5 tonne |
> 2.5-3.5ton |
|
6 |
LGV6 |
Light goods vehicles >3.5-5.5 tonne |
>3.5ton-5.5ton |
|
7 |
HGV7 |
Medium & heavy goods vehicles > 5.5-15 tonne |
>5.5ton-15ton |
|
8 |
HGV8 |
Medium & heavy goods
vehicles with > 15 tonne |
> 15ton |
|
11 |
PLB |
Public light
buses |
All |
|
12 |
PV4 |
Private light buses ≤ 3.5 tonne |
≤ 3.5ton |
|
13 |
PV5 |
Private light buses > 3.5 tonne |
> 3.5ton |
|
14 |
NFB6 |
Non-franchised buses ≤ 6.4 tonne |
≤ 6.4ton |
|
15 |
NFB7 |
Non-franchised buses 6.4-15
tonne |
>6.4-15ton |
|
16 |
NFB8 |
Non-franchised buses > 15 tonne |
>15ton |
|
17 |
FBSD |
Single deck franchised buses |
All |
|
18 |
FBDD |
Double deck
franchised buses |
All |
|
19 |
MC |
Motor cycles |
All |
4.7.30. Roads within the study area were grouped into 4 different categories as tabulated in Table 4.5.
Table 4.5 Road Groupings
|
Road Type |
Road Type Code |
Description |
|
Expressway |
EX |
Roads are designated as expressways under the Road Traffic (Expressway) Regulations. High capacity roads with no frontage access or development, pedestrians segregated, widely spaced grade-separated junctions. 24 hour stopping restrictions. |
|
Primary distributor |
PD |
Roads with speed limit of 50 kph and with no frontage access.
Usually 24 hour stopping restrictions. |
|
District distributor |
DD |
Roads with speed limit of 50 kph and with junctions, pedestrian
crossing and bus stop, etc. Usually peak hour stopping restrictions and
parking restrictions throughout the day. |
|
Local distributor |
LD |
Roads with speed limit of 50 kph and with capacity limited by
waiting vehicles and etc. |
· Exhaust Technology Fractions
4.7.31. EMFAC-HK includes as default all the existing vehicle emission control programmes, where the implementation schedule of vehicle emission standards for different vehicle classes is presented in Appendix II of the Guideline on Modelling Vehicle Emissions.
4.7.32. Since the proposed Project only involves activities such as parking and vehicle repair / testing and no emission control programme will be imposed, default values of such exhaust technology fractions remained unchanged.
4.7.33. The vehicle population function in EMFAC-HK is only for natural replacement, no policy change can be reflected with this function. The proposed Project does not have influence on the age distribution, the default vehicle population forecast was adopted.
4.7.34. As forecast information in the model year is absent for the proposed Project, default value was adopted in accordance with the EMFAC-HK Guideline on Modelling Vehicle Emissions.
· Daily Vehicle Mile Travelled (VMT)
4.7.35. VMTs were inputted in the model to represent the total distance travelled on a typical weekday. The site specific VMTs were calculated by multiplying the number of vehicles by the road length.
4.7.36. The diurnal traffic pattern was inputted to simulate the effect on the emissions, in which the daily traffic flow variation was estimated by the Traffic Consultant of the proposed Project. The traffic assessment report is currently seeking the endorsement from TD.
· Diurnal Variation of Daily Trips
4.7.37. Diurnal variation of daily trips was used to estimate the start emissions of petrol and LPG vehicles. Trips for vehicles other than petrol and LPG types are assumed to be zero. Estimations on the number of trips carried out per day for petrol and LPG vehicles were assumed as follows.
4.7.38. For expressway and primary distributor, number of trips per day was assumed to be zero because no cold start is expected on these road sections under normal circumstance.
4.7.39. For district distributor and local distributor, it was assumed that the number of trips would be equal to the number of cold starts in district distributors and local distributors. It was also assumed that the number of trips was directly proportional to VMT and this pattern was similar within the Hong Kong territory. Therefore, the number of trips for the proposed Project was estimated by the formula:
|
Trip
(within study area) |
= |
Trip
(within Hong Kong) |
× VMT
(within study area) |
|
VMT
(within Hong Kong) |
4.7.40. Trip per VMT (within Hong Kong) for each vehicle class was calculated based on the default data of EMFAC-HK whereas VMT (within study area) was the result of multiplying the number of vehicles for that particular vehicle class by the road length travelled within the study area.
4.7.41. It was believed that the types of road sections within the study area are typical in nature and similar to the conditions in Hong Kong, default speed fractions in EMFAC-HK were adopted.
4.7.42. Emfac mode of EMFAC-HK was employed.
4.7.43. Hourly emission factors were derived for 24-hour diurnal variation.
· Calculation of Emission Factors
4.7.44. Emission inventories and VMT were extracted from the model. Given the continuous flow nature of expressway and primary distributor, only running exhaust emission is considered; whereas both starting exhaust and running exhaust emissions were taken into account for road sections of district distributor and local distributor. The starting exhaust emission is however confined to petrol- and LPG-fuelled vehicles only.
4.7.45. The running exhaust emission includes the vehicle tailpipe emission while it is travelling on the road at various speeds and idling at intersections.
4.7.46. Proven by the EMFAC-HK output file, the highest cold start NOx emission occurs when the engine restarts after 120-minute resting, whilst the highest PM10 and PM2.5 emission occurs after 720-minute resting. Such assumptions were considered to be conservative and adopted for all vehicle classes at different meteorological conditions.
4.7.47. Generic emission factors for each of the vehicle categories in different temperature, relative humidity and speed were directly extracted from the EMFAC-HK output files. Composite emissions factors were then calculated for each road section in 24-hour diurnal traffic flow.
4.7.48. The calculated emission factors in terms of g/miles/vehicle in that particular hour were used in CALINE 4 for estimating road traffic emissions. That information is summarised in Appendix 4.3.
Determination of Emissions Induced by Vehicular Travelling within the Proposed Project
4.7.49. The predicted hourly NO2, PM10 and PM2.5 concentrations were derived from the ISCST3 modelling at 1.5 m, 5 m, and 10 m above ground at each representative ASRs in the study area. The hourly emission rates calculated by EMFAC-HK were used for the vehicular emissions from travelling within the proposed Project. Relevant correspondence showing the endorsement of the traffic forecasts by the TD are shown in Appendix 5.3. Emission rate, including running exhaust and starting exhaust, was predicted by EMFAC-HK, using the same approach of determining the emission rate from open roads as aforementioned. To estimate the worst-case emissions at the Project site, the following was assumed:
· The travelling distance of the vehicles within the site was assumed to be the longest travelling distance of 1000 m;
· Travelling speed was assumed to be 5 kph and 1 cold start was included for each trip;
· Vehicle breakdown followed the in and out traffic data obtained from future users; and
· The highest cumulative 1-hour average of pollutant emission rate among the 24-hour operating period was chosen for any other operating hour of a typical day.
4.7.50. In this study, it was assumed that the proposed Project will optimise the use of natural ventilation and will be supplemented with the mechanical ventilation. Hence, the emissions in the parking area were estimated as total emission in grams by EMFAC-HK at hourly basis in accordance with the hourly traffic data, which was then assumed to be released as volume sources through each opening in proportion to size of opening area. The size of the opening was assumed to follow the minimum requirements of permeability of building as recommended by the Buildings Department. Details of emission rate calculation and estimated location of volume sources are shown in Appendix 4.4 and Figure 4.3 respectively.
Determination of Emissions Induced by Vehicular Idling Activities within the Proposed Project
4.7.51. Some of the vehicles under repair / testing activities require engine running when it needs operating the hydraulic moving parts for braking test, engine test etc. The engine on-time duration is just a few minutes each time for preparing the aforesaid repair / testing works. Generally speaking, engine would then be turned off for carrying out the repair / testing works and no need to be turned on during the rest of the repair / testing time. All the proposed vehicle repair / testing activities and examination works were assumed to be limited to the normal working hours (0800 to 1800 hours) at the EMSD Depot and the HKPF PVP&EC respectively. Although the HKPF will be operated 24 hours a day, the vehicle testing activities is considered negligible during evening and night-time.
4.7.52. The activities of each future user department that require engine running are summarised in Table 4.6.
Table 4.6 Activity List Requiring Engine Running
|
HKPF PVP&EC |
EMSD Depot |
FEHD Depot |
GL Specialist
Laboratory |
|
Braking test (on grade) |
Braking test (for
vehicles other than motorcycle) |
Vehicle washing |
Nil |
|
Braking test (on slope) |
Engine testing |
|
|
|
Vehicle examination (in
pit) |
|
|
|
|
Vehicle examination (at
ground) |
|
|
|
4.7.53.
As the vehicle repair / testing
activities involving idling would be come-and-go basis, maximum engine on-time
per each vehicle was assumed to be maximal 15 minutes in an hour of the repair
/ testing period as a conservative approach, although the repair / testing
period for each vehicle may last for about 2 to 3 hours. The number of vehicles
under repair / testing was limited by the number of repair / testing bays. Such
assumptions are summarised below and were used for the operational activities that
require engine running, including vehicle washing in the FEHD Depot, vehicle repair
/ testing in the EMSD Depot and vehicle examination works in the HKPF
PVP&EC.
· Idling activity per vehicle lasts for maximum 900 seconds (15 minute) in 1 hour; and
· Maximum 20 idling vehicles in 1 hour.
4.7.54. No vehicle repair / testing, maintenance work that requires engine running will be involved as verified by the GL.
4.8.1. The potential dust emission sources would be mainly from the construction work activities of the excavation and wind erosion at the work site. As the size of the work site is limited and the excavation is minor such that the amount of excavated materials generated would be small, no adverse dust impact would be anticipated at the representative ASRs with the implementation of sufficient dust suppression measures as stipulated under the Air Pollution Control (Construction Dust) Regulation and good site practices.
4.8.2. The implementation of sufficient dust suppression measures as stipulated under the Air Pollution Control (Construction Dust) Regulation and good site practices should be carried out in order to further minimise the construction dust generated. The following measures are specifically recommended for implementation together with those presented in the aforementioned regulation.
· Use of regular watering, to reduce dust emissions from exposed site surfaces and unpaved roads, particularly during dry weather;
· Use of frequent watering for particularly 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 points of the site;
· Imposition of speed controls 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;
· Every stock of more than 20 bags of cement or dry pulverised fuel ash (PFA) , if applicable, should be covered entirely by impervious sheeting or placed in an area sheltered on the top and the 3-sides; and
· Loading, unloading, transfer, handling or storage of large amount of cement or dry PFA should be carried out in a totally enclosed system or facility, and nay vent or exhaust should be fitted with the an effective fabric filter or equivalent air pollution control system.
Determination of Assessment Year
4.8.3. Composite emission factors for each road links were calculated based on the weighted average of the emission factors of 16 vehicle classes. As both of the NOx and PM10 emissions within the study area are the highest in the first year of occupancy, i.e. 2018, among the years 2018, 2023 and 2033, hence this worst assessment year was adopted for air quality modelling. The total NOx, PM10 and PM2.5 emission inventory for the selected years are tabulated in Table 4.7, Table 4.8 and Table 4.9 respectively for comparison. Detailed information is summarised in Appendix 4.3.
Table 4.7 Total NOx Emission Inventory for Selected Years
|
NOx Emission Inventory (g/day) |
2018 w/o Project |
2018 w/ Project |
2023 w/ Project |
2033 w/ Project |
|
Total |
77,798 |
78,430 |
54,145 |
26,065 |
|
Notes:
[1]
“w/o Project” denotes the cases without the proposed Project in place. [2]
“w/ Project” denotes the cases with the proposed Project in place. [3]
The highest emission inventory is underlined. |
||||
Table 4.8 Total PM10 Emission Inventory for Selected Years
|
PM10
Emission Inventory (g/day) |
2018 w/o Project |
2018 w/ Project |
2023 w/ Project |
2033 w/ Project |
|
Total |
2,953 |
2,980 |
2,106 |
1,319 |
|
Notes: [1] “w/o Project”
denotes the cases without the proposed Project in place. [2] “w/ Project”
denotes the cases with the proposed Project in place. [3] The highest
emission inventory is underlined. |
||||
Table 4.9 Total PM2.5 Emission Inventory for Selected Years
|
PM2.5
Emission Inventory (g/day) |
2018 w/o Project |
2018 w/ Project |
2023 w/ Project |
2033 w/ Project |
|
Total |
2,714 |
2,738 |
1,937 |
1,215 |
|
Notes: [1] “w/o Project”
denotes the cases without the proposed Project in place. [2] “w/ Project”
denotes the cases with the proposed Project in place. [3] The highest
emission inventory is underlined. |
||||
4.8.4. Based on the above, it was observed that change of emission inventory with the proposed Project in place was less than 1% of increment.
Calculated Open Road Emissions in 2018
4.8.5. The calculated emission factors for different vehicle categories for the year 2018 are listed in Appendix 4.3. The whole set of the calculated emission factors (hour 1 to hour 24) were used for the calculation of the composite emission factors for the CALINE 4 modelling.
Emissions Induced by Vehicular Travelling within the Proposed Project in 2018
4.8.6. The predicted hourly NO2, PM10 and PM2.5 concentrations were derived from the ISCST 3 modelling at 1.5m, 5m, and 10m above ground at the representative ASRs in the study area. Calculation of composite emission factors for ISCST 3 modelling is shown in Appendix 4.4.
Emissions Induced by
Vehicular Idling Activities within the Proposed Project in 2018
4.8.7. The vehicle repair / testing activities that require idling would be carried out within the proposed Project. Calculation of composite emission factors for ISCST 3 modelling is shown in Appendix 4.5.
Determination of Odour Emissions
4.8.8. As aforementioned in Section 3.3, a total of 17 spaces for RCVs among the 70 parking spaces, 1 manual vehicle washing bay and 1 automatic vehicle washing machine provided in the FEHD Depot. All RCVs that visit the proposed Project are of enclosed-type and comply with relevant regulations. As verified by the FEHD, the RCVs will be equipped with metal tailgate cover and deodourising system with an odour removal efficiency of 85% or above to control the spread of odour. The RCVs are run and operated by the FEHD in an environmentally hygienic manner.
4.8.9. Before entering the proposed Project, all refuse collected in the district has been fully off-loaded in the designated refuse disposal points and the RCVs have been well rinsed in the transfer station/ disposal site before departure. Extensive cleansing and clearance of refuse residual inside the compactor of the RCVs would not be carried out within the proposed Project, where only washing of the body shell of RCVs would be taken place either at the manual washing bay or passing through the automatic vehicle washing machine. All RCVs will be wiped dry before leaving proposed Project. Other daily operations include vehicle parking and water refilling for the street washing vehicles. Since there will be no maintenance work in the entire depot area, opening of the RCVs’ compactor is not anticipated. Between 0600 and 2300 hours every day, a maximum of 8 RCVs/ hour is expected to move in the proposed Project, where a total of 16 RCVs moving in per day. Having regard to the sufficient parking spaces, queuing of RCVs at the entrance is not expected. After 2300 hours, vehicle washing and other operational activities would be very limited. Traffic routing of RCVs will also be carefully arranged to avoid nuisance to surrounding sensitive areas.
4.8.10. Given the hygienic nature of RCV, provision of deodourising system and metal tailgate cover as well as unanticipated queuing at entrance, no odour emission is identified both at source of the RCVs and along its ingress/ egress traffic routing during the operating hours. Therefore potential odour impact imposed to the staff and workers of the proposed Project is not anticipated.
Determination of Volatile Chemicals Emissions from GL Specialist Laboratory
4.8.11. The main propose of the GL Specialist Laboratory is to provide chemical testing services for other Government departments. The testing handles environmental, food, medical/ Chinese medicine and commercial products. The chemical tests mainly involve wet chemistry (sample preparation, digestion, solvent extraction) and analytical chemistry. The type of organic and inorganic chemicals involved and their corresponding estimated emission rates in the testing are summarised in Appendix 4.6.
4.8.12. As confirmed with the GL, all extracted gases from fumehood during testing within the laboratory were treated with activated carbon or scrubber before discharge to outdoor air. The emission control procedures follow the ISO14001 management system.
4.8.13. The estimated emission rates of the organic and inorganic chemicals emanated due to the operation of the GL are to be of minimal amount and fulfil the threshold limit value/ permissible exposure limit of relevant international occupational safety and health requirements. Details are also shown in Appendix 4.6.
4.8.14. In this connection, impact due to the volatile chemicals emissions of the proposed Project is considered negligible.
4.9.1. The predicted overall cumulative 1-hour and annual average concentrations of NO2 and 24-hour and annual average concentrations of PM10 were calculated and are shown in Table 4.10 and Table 4.11 below.
4.9.2. In accordance with EPD guidelines, a factor of 0.71 and 0.75 were multiplied to the concentration of PM10 to determine the annual and daily ambient concentrations for PM2.5 respectively. 24-hour and annual average concentrations of PM2.5 are given in Table 4.12.
Table 4.10 Summary of NO2 Concentrations
|
ASR ID |
Description |
Assessment Height (mAG) |
19th Highest 1-hour Concentration (µg/m3) |
Annual Concentration (µg/m3) |
|
AQO (Number of Exceedances per Calendar Year
Allowed) |
200 (18) |
40 (N/A) |
||
|
ASR 1 |
Metro Recreational Club Chai Wan Depot Club House
(MTR Facilities) |
1.5 |
147.7 |
20.7 |
|
5 |
147.6 |
20.5 |
||
|
ASR 2 |
Heng Fa Chuen Lutheran Day Nursery |
1.5 |
146.7 |
20.2 |
|
5 |
146.7 |
20.1 |
||
|
ASR 3 |
Heng Fa Chuen Block 1 |
1.5 |
146.7 |
20.1 |
|
5 |
146.7 |
20.0 |
||
|
10 |
146.7 |
19.6 |
||
|
ASR 4 |
Heng Fa Chuen Block 50 |
1.5 |
148.3 |
19.3 |
|
5 |
148.2 |
19.1 |
||
|
10 |
147.9 |
18.7 |
||
|
ASR 5 |
Heng Fa Chuen Playground |
1.5 |
147.8 |
19.9 |
|
ASR 6 |
Government Logistics Centre |
1.5 |
148.4 |
19.8 |
|
5 |
148.2 |
18.6 |
||
|
10 |
147.9 |
18.0 |
||
|
ASR 7 |
NWFB Depot |
1.5 |
149.0 |
19.3 |
|
5 |
148.9 |
19.2 |
||
|
10 |
147.9 |
18.7 |
||
|
ASR 8 |
Hong Kong Institute of Vocational Education (Chai
Wan) - Academic Block |
1.5 |
149.1 |
22.0 |
|
5 |
149.0 |
21.6 |
||
|
10 |
148.6 |
20.7 |
||
|
ASR 9 |
Knight Court Flat A & B |
1.5 |
149.0 |
20.9 |
|
5 |
148.9 |
20.7 |
||
|
10 |
148.6 |
20.1 |
||
|
ASR 10 |
Knight Court Flat C & D |
1.5 |
148.8 |
21.2 |
|
5 |
148.7 |
20.9 |
||
|
10 |
148.5 |
20.3 |
||
|
ASR 11 |
Citybus Depot |
1.5 |
149.1 |
21.5 |
|
5 |
149.0 |
21.2 |
||
|
10 |
148.2 |
20.4 |
||
|
ASR 12 |
EMSD Workshop |
1.5 |
147.6 |
21.8 |
|
ASR 13 |
Wing Tai Road Garden |
1.5 |
149.7 |
22.4 |
|
ASR 14 |
Pamela Youde Nethersole Eastern Hospital - Block F |
1.5 |
151.0 |
23.9 |
|
5 |
151.0 |
23.6 |
||
|
10 |
151.0 |
22.9 |
||
|
ASR 15 |
Pamela Youde Nethersole Eastern Hospital - East
Block |
1.5 |
144.5 |
24.6 |
|
5 |
144.5 |
24.1 |
||
|
10 |
144.5 |
22.7 |
||
|
ASR 16 |
Tsui Wan Estate Playground |
1.5 |
153.8 |
28.2 |
|
ASR 17 |
Tsui Shou House, Tsui Wan Estate |
1.5 |
152.8 |
25.8 |
|
5 |
151.9 |
22.1 |
||
|
10 |
146.1 |
18.1 |
||
|
ASR 18 |
Endeavourers Chan Cheng Kit Wan Kindergarten |
1.5 |
153.0 |
26.2 |
|
ASR 19 |
Tsui Ching House, Hang Tsui Court |
1.5 |
148.6 |
23.7 |
|
5 |
148.6 |
21.6 |
||
|
10 |
147.0 |
18.0 |
||
|
ASR 20 |
Tsui Wan Nursing Home Limited |
1.5 |
147.4 |
19.4 |
|
ASR 21 |
Tsui Wan Estate Shopping Complex |
1.5 |
146.1 |
18.6 |
|
5 |
145.9 |
18.3 |
||
|
ASR 22 |
S.K.H Li Fook Hing Secondary School |
1.5 |
145.8 |
18.0 |
|
5 |
145.7 |
17.8 |
||
|
10 |
145.6 |
17.3 |
||
|
ASR 23 |
TWGHs & LKWFSL Mrs Fung Yiu Hing Memorial
Primary School |
1.5 |
148.0 |
20.6 |
|
5 |
147.4 |
19.7 |
||
|
10 |
146.1 |
17.7 |
||
|
ASR 24 |
Chai Wan Fire Station |
1.5 |
153.9 |
21.2 |
|
5 |
151.6 |
18.3 |
||
|
10 |
147.8 |
15.9 |
||
|
ASR 25 |
Chai Wan Industrial City Phase II |
1.5 |
149.8 |
21.2 |
|
5 |
145.1 |
19.2 |
||
|
10 |
143.9 |
17.7 |
||
|
ASR 26 |
Ming Pao Industrial Centre Block B |
1.5 |
153.1 |
18.8 |
|
5 |
147.0 |
17.0 |
||
|
10 |
142.4 |
15.7 |
||
|
ASR 27 |
Safety Godown Industrial Building |
1.5 |
150.9 |
21.1 |
|
5 |
149.3 |
18.8 |
||
|
10 |
148.7 |
17.6 |
||
|
ASR 29 |
Planned
Pet Garden at Sheung On Street |
1.5 |
146.7 |
22.8 |
|
ASR 30 |
Planned THEi New Campus |
1.5 |
146.3 |
19.5 |
|
5 |
145.4 |
19.0 |
||
|
10 |
145.0 |
18.1 |
||
Table 4.11 Summary of PM10 Concentrations
|
ASR ID |
Description |
Assessment Height (mAG) |
10th Highest 24-hour Concentration (µg/m3) |
Annual Concentration (µg/m3) |
|
AQO (Number
of Exceedances per Calendar Year Allowed) |
100 (9) |
50 (N/A) |
||
|
ASR 1 |
Metro Recreational Club Chai Wan Depot Club House
(MTR Facilities) |
1.5 |
73.1 |
38.7 |
|
5 |
73.0 |
38.7 |
||
|
ASR 2 |
Heng Fa Chuen Lutheran Day Nursery |
1.5 |
73.0 |
38.7 |
|
5 |
73.0 |
38.7 |
||
|
ASR 3 |
Heng Fa Chuen Block 1 |
1.5 |
73.0 |
38.7 |
|
5 |
73.0 |
38.7 |
||
|
10 |
73.0 |
38.6 |
||
|
ASR 4 |
Heng Fa Chuen Block 50 |
1.5 |
72.9 |
38.6 |
|
5 |
72.9 |
38.6 |
||
|
10 |
72.9 |
38.6 |
||
|
ASR 5 |
Heng Fa Chuen Playground |
1.5 |
72.9 |
38.7 |
|
ASR 6 |
Government Logistics Centre |
1.5 |
72.9 |
38.7 |
|
5 |
72.9 |
38.6 |
||
|
10 |
72.9 |
38.6 |
||
|
ASR 7 |
NWFB Depot |
1.5 |
73.0 |
38.7 |
|
5 |
73.0 |
38.6 |
||
|
10 |
73.0 |
38.6 |
||
|
ASR 8 |
Hong Kong Institute of Vocational Education (Chai
Wan) - Academic Block |
1.5 |
73.2 |
38.7 |
|
5 |
73.1 |
38.7 |
||
|
10 |
73.1 |
38.7 |
||
|
ASR 9 |
Knight Court Flat A & B |
1.5 |
73.1 |
38.7 |
|
5 |
73.1 |
38.7 |
||
|
10 |
73.0 |
38.7 |
||
|
ASR 10 |
Knight Court Flat C & D |
1.5 |
73.1 |
38.7 |
|
5 |
73.1 |
38.7 |
||
|
10 |
73.1 |
38.7 |
||
|
ASR 11 |
Citybus Depot |
1.5 |
73.1 |
38.7 |
|
5 |
73.1 |
38.7 |
||
|
10 |
73.1 |
38.7 |
||
|
ASR 12 |
EMSD Workshop |
1.5 |
72.5 |
38.4 |
|
ASR 13 |
Wing Tai Road Garden |
1.5 |
72.5 |
38.4 |
|
ASR 14 |
Pamela Youde Nethersole Eastern Hospital - Block F |
1.5 |
73.8 |
39.4 |
|
5 |
73.8 |
39.4 |
||
|
10 |
73.8 |
39.4 |
||
|
ASR 15 |
Pamela Youde Nethersole Eastern Hospital - East
Block |
1.5 |
73.4 |
39.2 |
|
5 |
73.4 |
39.2 |
||
|
10 |
73.3 |
39.1 |
||
|
ASR 16 |
Tsui Wan Estate Playground |
1.5 |
73.3 |
38.7 |
|
ASR 17 |
Tsui Shou House, Tsui Wan Estate |
1.5 |
73.1 |
38.6 |
|
5 |
72.8 |
38.4 |
||
|
10 |
72.4 |
38.2 |
||
|
ASR 18 |
Endeavourers Chan Cheng Kit Wan Kindergarten |
1.5 |
73.1 |
38.6 |
|
ASR 19 |
Tsui Ching House, Hang Tsui Court |
1.5 |
72.8 |
38.5 |
|
5 |
72.7 |
38.4 |
||
|
10 |
72.3 |
38.2 |
||
|
ASR 20 |
Tsui Wan Nursing Home Limited |
1.5 |
72.4 |
38.3 |
|
ASR 21 |
Tsui Wan Estate Shopping Complex |
1.5 |
72.3 |
38.3 |
|
5 |
72.2 |
38.2 |
||
|
ASR 22 |
S.K.H Li Fook Hing Secondary School |
1.5 |
72.2 |
38.2 |
|
5 |
72.2 |
38.2 |
||
|
10 |
72.1 |
38.2 |
||
|
ASR 23 |
TWGHs & LKWFSL Mrs Fung Yiu Hing Memorial
Primary School |
1.5 |
72.5 |
38.3 |
|
5 |
72.4 |
38.3 |
||
|
10 |
72.2 |
38.2 |
||
|
ASR 24 |
Chai Wan Fire Station |
1.5 |
72.8 |
38.4 |
|
5 |
72.4 |
38.3 |
||
|
10 |
72.0 |
38.2 |
||
|
ASR 25 |
Chai Wan Industrial City Phase II |
1.5 |
72.3 |
38.4 |
|
5 |
72.2 |
38.3 |
||
|
10 |
72.0 |
38.2 |
||
|
ASR 26 |
Ming Pao Industrial Centre Block B |
1.5 |
72.5 |
38.3 |
|
5 |
72.0 |
38.2 |
||
|
10 |
71.8 |
38.2 |
||
|
ASR 27 |
Safety Godown Industrial Building |
1.5 |
72.9 |
38.8 |
|
5 |
72.9 |
38.7 |
||
|
10 |
72.9 |
38.6 |
||
|
ASR 29 |
Planned
Pet Garden at Sheung On Street |
1.5 |
72.4 |
38.4 |
|
ASR 30 |
Planned THEi New Campus |
1.5 |
72.1 |
38.3 |
|
5 |
72.1 |
38.3 |
||
|
10 |
72.0 |
38.2 |
||
Table 4.12 Summary of PM2.5 Concentrations
|
ASR ID |
Description |
Assessment Height (mAG) |
10th Highest 24-hour Concentration (µg/m3) |
Annual Concentration (µg/m3) |
|
AQO (Number
of Exceedances per Calendar Year Allowed) |
75 (9) |
35 (N/A) |
||
|
ASR 1 |
Metro Recreational Club Chai Wan Depot Club House
(MTR Facilities) |
1.5 |
54.8 |
27.5 |
|
5 |
54.8 |
27.5 |
||
|
ASR 2 |
Heng Fa Chuen Lutheran Day Nursery |
1.5 |
54.8 |
27.5 |
|
5 |
54.8 |
27.5 |
||
|
ASR 3 |
Heng Fa Chuen Block 1 |
1.5 |
54.7 |
27.5 |
|
5 |
54.7 |
27.5 |
||
|
10 |
54.7 |
27.5 |
||
|
ASR 4 |
Heng Fa Chuen Block 50 |
1.5 |
54.7 |
27.5 |
|
5 |
54.7 |
27.5 |
||
|
10 |
54.7 |
27.4 |
||
|
ASR 5 |
Heng Fa Chuen Playground |
1.5 |
54.7 |
27.5 |
|
ASR 6 |
Government Logistics Centre |
1.5 |
54.7 |
27.5 |
|
5 |
54.7 |
27.4 |
||
|
10 |
54.7 |
27.4 |
||
|
ASR 7 |
NWFB Depot |
1.5 |
54.8 |
27.5 |
|
5 |
54.8 |
27.5 |
||
|
10 |
54.7 |
27.4 |
||
|
ASR 8 |
Hong Kong Institute of Vocational Education (Chai
Wan) - Academic Block |
1.5 |
54.9 |
27.6 |
|
5 |
54.9 |
27.5 |
||
|
10 |
54.8 |
27.5 |
||
|
ASR 9 |
Knight Court Flat A & B |
1.5 |
54.8 |
27.5 |
|
5 |
54.8 |
27.5 |
||
|
10 |
54.8 |
27.5 |
||
|
ASR 10 |
Knight Court Flat C & D |
1.5 |
54.9 |
27.5 |
|
5 |
54.9 |
27.5 |
||
|
10 |
54.8 |
27.5 |
||
|
ASR 11 |
Citybus Depot |
1.5 |
54.9 |
27.6 |
|
5 |
54.9 |
27.5 |
||
|
10 |
54.8 |
27.5 |
||
|
ASR 12 |
EMSD Workshop |
1.5 |
54.5 |
27.3 |
|
ASR 13 |
Wing Tai Road Garden |
1.5 |
54.5 |
27.3 |
|
ASR 14 |
Pamela Youde Nethersole Eastern Hospital - Block F |
1.5 |
55.5 |
28.0 |
|
5 |
55.4 |
28.0 |
||
|
10 |
55.4 |
28.0 |
||
|
ASR 15 |
Pamela Youde Nethersole Eastern Hospital - East
Block |
1.5 |
55.1 |
27.9 |
|
5 |
55.1 |
27.9 |
||
|
10 |
55.1 |
27.8 |
||
|
ASR 16 |
Tsui Wan Estate Playground |
1.5 |
55.1 |
27.6 |
|
ASR 17 |
Tsui Shou House, Tsui Wan Estate |
1.5 |
55.0 |
27.5 |
|
5 |
54.7 |
27.3 |
||
|
10 |
54.4 |
27.2 |
||
|
ASR 18 |
Endeavourers Chan Cheng Kit Wan Kindergarten |
1.5 |
55.0 |
27.5 |
|
ASR 19 |
Tsui Ching House, Hang Tsui Court |
1.5 |
54.8 |
27.4 |
|
5 |
54.7 |
27.3 |
||
|
10 |
54.4 |
27.2 |
||
|
ASR 20 |
Tsui Wan Nursing Home Limited |
1.5 |
54.4 |
27.2 |
|
ASR 21 |
Tsui Wan Estate Shopping Complex |
1.5 |
54.3 |
27.2 |
|
5 |
54.3 |
27.2 |
||
|
ASR 22 |
S.K.H Li Fook Hing Secondary School |
1.5 |
54.2 |
27.2 |
|
5 |
54.2 |
27.2 |
||
|
10 |
54.2 |
27.2 |
||
|
ASR 23 |
TWGHs & LKWFSL Mrs Fung Yiu Hing Memorial
Primary School |
1.5 |
54.5 |
27.3 |
|
5 |
54.4 |
27.3 |
||
|
10 |
54.3 |
27.2 |
||
|
ASR 24 |
Chai Wan Fire Station |
1.5 |
54.8 |
27.3 |
|
5 |
54.4 |
27.2 |
||
|
10 |
54.1 |
27.1 |
||
|
ASR 25 |
Chai Wan Industrial City Phase II |
1.5 |
54.4 |
27.3 |
|
5 |
54.3 |
27.2 |
||
|
10 |
54.1 |
27.2 |
||
|
ASR 26 |
Ming Pao Industrial Centre Block B |
1.5 |
54.5 |
27.3 |
|
5 |
54.1 |
27.2 |
||
|
10 |
53.9 |
27.1 |
||
|
ASR 27 |
Safety Godown Industrial Building |
1.5 |
54.7 |
27.6 |
|
5 |
54.7 |
27.5 |
||
|
10 |
54.7 |
27.4 |
||
|
ASR 29 |
Planned
Pet Garden at Sheung On Street |
1.5 |
54.4 |
27.4 |
|
ASR 30 |
Planned THEi New Campus |
1.5 |
54.2 |
27.2 |
|
5 |
54.1 |
27.2 |
||
|
10 |
54.1 |
27.2 |
||
4.9.3. Under the worst case scenario (i.e. Year 2018 with Project), the predicted 19th highest cumulative 1-hour NO2 concentration at the representative ASRs are in the range of 142.4 to 153.9µg/m3 with the highest found at ASR 24 (Chai Wan Fire Station). The predicted number of exceedances against the AQO is below 18, and thus no non-compliance is found. Corresponding contour map is given in Figure 4.5.
4.9.4. The predicted cumulative annual NO2 concentration at the representative ASRs are in the range of 15.7 to 28.2µg/m3 with the highest found at ASR 16 (Tsui Wan Estate Playground). No non-compliance against the AQO is found. Corresponding contour map is given in Figure 4.4.
4.9.5. Under the worst case scenario (i.e. Year 2018 with Project), the predicted 10th highest cumulative 24-hour PM10 concentration at the representative ASRs are in the range of 71.8 to 73.8 µg/m3 with the highest found at ASR 14 (Pamela Youde Nethersole Eastern Hospital – Block F). The predicted number of exceedances against the AQO is below 9, and thus no non-compliance is found. Corresponding contour map is given in Figure 4.7
4.9.6. The predicted cumulative annual PM10 concentration at the representative ASRs are in the range of 38.2 to 39.4µg/m3 with the highest also found at ASR 14. No non-compliance against the AQO is found. Corresponding contour map is given in Figure 4.6.
4.9.7. Under the worst case scenario (i.e. Year 2018 with Project), the predicted 10th highest cumulative 24-hour PM2.5 concentration at the representative ASRs are in the range of 53.9 to 55.5µg/m3 with the highest found at ASR 14 (Pamela Youde Nethersole Eastern Hospital – Block F). The predicted number of exceedances against the AQO is below 9, and thus no non-compliance is found. Corresponding contour map is given in Figure 4.9.
4.9.8. The predicted cumulative annual PM2.5 concentration at the representative ASRs are in the range of 27.1 to 28.0µg/m3 with the highest also found at ASR 14. No non-compliance against the AQO is found. Corresponding contour map is given in Figure 4.8.
4.10.1. Mitigation measures listed in Section 4.8 are recommended to be implemented during construction of the proposed Project.
4.10.2. According to the above Section 4.9, no adverse air quality impact is predicted in association with the operation of the proposed Project without mitigation measures. Therefore, no mitigation measure is required during operation. Nevertheless, a number of initiatives aimed at further reduction in air emissions are proposed to avoid the potential nuisance arising from their operations.
|
Facilities |
Initiatives |
|
FEHD Depot |
There will be metal tailgate cover and deodourising
system with odour removal efficiency of 85% or above equipped in every RCVs to
mitigate the spread of odour. |
|
GL Specialist Laboratory |
Activated carbon or scrubber will be equipped in the
GL to treat the extracted gases from fumehood prior to discharge. |
4.11.1. No adverse residual impact during construction and operation phases of the proposed Project would be anticipated, provided that the dust suppression measures during construction phase aforementioned in Section 4.8 are properly implemented.
4.12.1. No adverse dust impact is anticipated at each representative ASRs, given that dust suppression measures during construction phase aforementioned in Section 4.8 and recommendations under the Air Pollution Control (Construction Dust) Regulation are properly implemented. Regular site environmental audits during the construction of the proposed Project shall be conducted in accordance with the requirements in EM&A Manual.
4.12.2. The results of the operation air quality impact assessment showed that no adverse impact due to vehicular movement, odour as well as laboratory emission would be anticipated during the operation of the proposed Project. Hence, EM&A auditing work is considered not necessary.
4.13.1. Air quality impact, odour and volatile chemicals emissions assessments were conducted for the construction and operation phases of the proposed Project within the 500 m study area.
4.13.2. For the construction aspect, there would be no major earthworks carried out for the site formation works of the Project site. With the implementation of sufficient dust suppression measures as recommended and stipulated under the Air Pollution Control (Construction Dust) Regulation, adverse construction dust impact would not be anticipated.
4.13.3. For the operation of the proposed Project, no adverse air quality impacts would be anticipated as there would be limited vehicular emissions from the repair / testing and parking activities of the proposed Project, considered with the cumulative effect of emissions from open roads networks within the 500m study area. Results show that the predicted 19th highest 1-hour and annual average NO2 and 10th highest daily and annual average PM2.5 and PM10 concentrations at each representative ASRs complied with the AQOs. No mitigation measure is required.
4.13.4. In view of the fact that extensive cleansing and clearance of refuse residual inside the compactor of the RCVs would be not carried out within the proposed Project, provision of deodourising system and no queuing at entrance is anticipated at the entrance, potential odour emissions would be negligible at the RCVs itself and along the traffic routes to/from the Project site. In other words, potential odour nuisance associated with the operation of the proposed Project is anticipated to be negligible.
4.13.5. Lastly, the estimated emission rates of the organic and inorganic chemicals emanated due to the operation of the GL Specialist Laboratory are to be of minimal amount and fulfil the threshold limit value/ permissible exposure limit of relevant occupational safety and health requirements. Potential volatile chemicals emissions associated with the operation of the proposed Project are negligible.
·
PIARC Technical Committee on Road Tunnel Operation. (2004). Road
Tunnels: Vehicle Emissions and Air Demand for Ventilation
·
Occupational Safety and Health Standards, Table Z-1 Limits for Air
Contaminants. Occupational Safety and Health Administrative (OSHA), Department
of Labor, United States. Retrieved 6 February 2015, from
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9992
·
Occupational Safety and Health Standards, Table Z-2. Occupational Safety
and Health Administrative (OSHA), Department of Labor, United States. Retrieved
6 February 2015, from
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9993&p_table=STANDARDS
·
American Conference of Governmental and Industrial Hygienists’ threshold
limit value. American Conference of Governmental and Industrial Hygienists
(ACCIH). Retrieved 6 February 2015, from
http://www.acgih.org/store/BrowseProducts.cfm?type=cat&id=16
·
Chronic inhalation exposure limit. (2002). Office of Environmental
Health Hazard Assessment (OEHHA), California, USA. Retrieved 6 February 2015,
from