3.0....... AIR IMPACT ASSESSMENT
3.1 Introduction
3.2
Environmental Legislation, Standards and
Guidelines
3.3
Description of the Environment
3.4
Assessment Area and Air Sensitive
Receivers (ASRs)
3.5
Construction Air Quality Impact Assessment
3.6
Operation Air Quality Impact Assessment
3.7
EM&A Requirements
3.8
Conclusion
FIGURES
Figure 3.1 New Scheme with 500m Assessment Area
Figure 3.2 Locations
of Representative Air Sensitive Receivers
Figure 3.3 Contour at 1.5m Level for the Cumulative Unmitigated 19th
1-hour and Annual NO2 Concentrations, and 10th Highest 24-hour and Annual
RSP/FSP Concentrations at 1.5m above Local Ground
Figure 3.4 Site Survey Route and Observations
APPENDICES
Appendix 3.1 Sensitivity Test
Appendix 3.2 Traffic Flow Data of Year 2025 to
2040
Appendix 3.3 Speed Fraction for EMFAC Model
Appendix 3.4 Vehicle Speed at Each Road Section
Appendix 3.5 Vehicle Emission Factor
Appendix 3.6 Composite Emission Factor
Appendix 3.7 Detailed Air Pollutant
Concentration at Representative ASRs
Appendix 3.8 Temperature and Humidity Data in
Year 2018
This section presents the potential air
quality impacts associated with the construction and operation phases of the
Project. Potential air quality impacts are expected to be dust nuisance during
the construction phase and vehicular emissions during the operation phase. Air
sensitive receivers (ASRs) have been identified for assessing the potential air
quality impacts on these receivers. Appropriate mitigation measures are
proposed to alleviate the potential air quality impacts if necessary.
The criteria and guidelines for
evaluating and assessing air quality impact are stated in Section 1 of Annex 4
and Annex 12 of the Technical Memorandum on Environmental Impact Assessment
Process (EIAO-TM).
The Air Pollution Control Ordinance
(Cap. 311) provides for the control of air pollutants from a variety of
stationary and mobile sources through the establishment of a set of Air Quality
Objectives (AQOs). As of 1st January 2014, a new set of air quality objectives
which stipulates maximum concentrations for a range of pollutants, namely
nitrogen dioxide (NO2), sulphur dioxide (SO2), respirable
suspended particulates (RSP or PM10), fine suspended particulates
(FSP or PM2.5), carbon monoxide (CO), Ozone (O3) and lead
(Pb) has been in force. The AQOs are listed in Table 3.1 below.
Table 3.1 Hong Kong Air Quality Objectives
|
Pollutant |
Averaging Time |
Concentration Limit (μg/m3) |
Number of Exceedance Allowed |
|
Sulphur dioxide |
10-minute |
500 |
3 |
|
24-hour |
125 |
3 |
|
|
RSP (PM10) |
24-hour |
100 |
9 |
|
Annual |
50 |
Not applicable |
|
|
FSP (PM2.5) |
24-hour |
75 |
9 |
|
Annual |
35 |
Not applicable |
|
|
Nitrogen dioxide |
1-hour |
200 |
18 |
|
Annual |
40 |
Not applicable |
|
|
Ozone |
8-hour |
160 |
9 |
|
Carbon monoxide |
1-hour |
30,000 |
0 |
|
8-hour |
10,000 |
0 |
|
|
Lead |
Annual |
0.5 |
Not applicable |
Note:
[i] All measurements of the
concentration of gaseous air pollutants, i.e. sulphur dioxide, nitrogen
dioxide, ozone and carbon monoxide, are to be adjusted to a reference
temperature of 293Kelvin and a reference pressure of 101.325 kilopascal.
[ii] Respirable suspended particulates
mean suspended particles in air with a nominal aerodynamic diameter of 10 μm or less.
[iii] Fine suspended particulates
mean suspended particles in air with a nominal aerodynamic diameter of 2.5 μm or less.
For construction dust, Annex 4 of
EIAO-TM specifies a Total Suspended Particulates (TSP) limit concentration
averaged over a 1-hour period to be 500 µg/m3. Mitigation measures for
construction sites have been specified in the Air Pollution Control
(Construction Dust) Regulation. It also requires contractors and site agents to
inform EPD and adopt dust reduction measures while carrying out “Notifiable
Works” or “Regulatory Works” as defined under the regulation. Works relevant to
this Project include both “Notifiable Works” (road construction) and
“Regulatory Works” (dusty materials handling, excavation).
The
location of the Project is shown in Figure 1.1. The land use
in the assessment area is mainly rural and residential with low-rise
developments. Dominant air emission sources are identified to be the traffic
emissions from Kam Tin Road and Lam Kam Road.
The
nearest EPD fixed air quality monitoring station is located at Yuen Long
District Office. The annual average
monitoring data recorded at EPD’s Yuen Long air quality monitoring station has
shown steady decreasing trend of pollutants’ concentration in the past five
years. The air quality
concentrations of the relevant air pollutants (i.e. NO2, CO, RSP and
FSP) ib the recent five years (2014 – 2018) are summarised in Table 3.2.
Table 3.2
Average Concentrations
of Pollutant in the Recent Five Years (Year 2014 – 2018) at Yuen Long EPD Air
Quality Monitoring Station
|
Pollutant |
2014 |
2015 |
2016 |
2017 |
2018 |
Mean |
|
19th Highest 1-hr NO2
Concentration (µg/m3) |
165 |
162 |
149 |
156 |
150 |
156.4 |
|
Annual Average NO2
Concentration (µg/m3) |
52 |
45 |
46 |
41 |
43 |
45.4 |
|
Highest 1-hr CO
Concentration (µg/m3) |
2560 |
2460 |
2080 |
1450 |
1720 |
2054 |
|
Highest 8-hr Average CO Concentration
(µg/m3) |
2319 |
2143 |
1474 |
1324 |
1574 |
1766.8 |
|
10th Highest Daily Average
RSP Concentration (µg/m3) |
124 |
102 |
86 |
87 |
75 |
94.8 |
|
Annual Average RSP
Concentration (µg/m3) |
50 |
44 |
37 |
40 |
37 |
41.6 |
|
10th Highest Daily
Average FSP Concentration (µg/m3) |
86 |
78 |
63 |
52 |
46 |
65 |
|
Annual Average FSP
Concentration (µg/m3) |
35 |
30 |
23 |
22 |
20 |
26 |
Based
on the monitoring data, there was a decreasing trend for the NO2
concentration in 19th highest hourly and annual average
concentrations, CO concentration in hourly and 8-hour average concentrations,
RSP and FSP pollutants concentrations in 10th highest daily average
concentration and annual average concentrations. With the exception of annual
average NO2, concentration for other pollutants and averaging times complied
with AQO for year 2018.
The
future year background concentrations are made reference to the EPD’s PATH-2016
modelling results. Since the tentative commencement year of the operation for
the Project would be in Year 2025, the PATH Model results for future year would
be made reference to Year 2020, which is considered representative and on
conservative basis. The pollutant concentrations of the assessment area
extracted from Year 2020 PATH results are presented in Table 3.3.
Table 3.3
Relevant Air Pollutant
Concentrations extracted from PATH-2016 Model
|
Pollutant |
PATH Grid Cell |
|||||||||||||||
|
Year 2020 |
||||||||||||||||
|
29,46 |
29,47 |
30,46 |
30,47 |
31,46 |
31,47 |
32,45 |
32,46 |
32,47 |
33,45 |
33,46 |
33,47 |
34,45 |
34,46 |
35,45 |
35,46 |
|
|
19th
Highest 1-hr NO2 Concentration (µg/m3) |
79.6 |
78.1 |
76.9 |
74.1 |
78 |
66.9 |
78 |
66.3 |
63 |
66 |
60.2 |
57.4 |
57.6 |
57.7 |
50.4 |
59.4 |
|
Annual
Average NO2 Concentration (µg/m3) |
13 |
12.4 |
12.4 |
11.5 |
12 |
11.1 |
11.3 |
11.3 |
11.1 |
10.9 |
11 |
11 |
9.5 |
10.5 |
8.5 |
10.3 |
|
Highest
1-hr CO Concentration (µg/m3) |
1001.9 |
997.3 |
996.5 |
999.6 |
988.3 |
1001.9 |
981.3 |
985.4 |
995.4 |
978.5 |
980.6 |
988.5 |
982 |
983.5 |
981 |
984.1 |
|
Highest
8-hr Average CO Concentration (µg/m3) |
832.7 |
812.2 |
801.7 |
813 |
803.2 |
805.6 |
798.3 |
804.5 |
810.1 |
795.1 |
799.8 |
808.3 |
797 |
797.1 |
804.4 |
798.7 |
|
10th
Highest Daily Average RSP Concentration (µg/m3) |
80.7 |
81.7 |
79.4 |
81.3 |
77.8 |
80.5 |
75.3 |
77 |
79.1 |
76.8 |
80 |
79.1 |
78.7 |
82.3 |
80.6 |
81.3 |
|
Annual
Average RSP Concentration (µg/m3) |
33.9 |
34.3 |
33.4 |
34.3 |
33.4 |
34 |
32.3 |
32.5 |
33.3 |
32.4 |
33.4 |
33.5 |
33.2 |
34.3 |
33.7 |
34.4 |
|
10th
Highest Daily Average FSP Concentration (µg/m3) |
60.5 |
61.3 |
59.6 |
61 |
58.3 |
60.4 |
56.5 |
57.7 |
59.3 |
57.6 |
60 |
59.3 |
59 |
61.7 |
60.5 |
61 |
|
Annual
Average FSP Concentration (µg/m3) |
24.1 |
24.4 |
23.7 |
24.4 |
23.7 |
24.1 |
22.9 |
23.1 |
23.7 |
23 |
23.7 |
23.8 |
23.6 |
24.4 |
24 |
24.4 |
Referring
to Section 3.4.4.2. of the EIA Study Brief, the assessment area for air quality
impact assessment shall be defined by a distance of 500m from the boundary of
the Project site. Figure 3.1 illustrates the Project
works area and assessment area for the air quality assessment.
With
reference to the relevant Outline Zoning Plans (OZPs) of Shek Kong (Plan no.:
S/YL-SK/9), Pat Heung (Plan no.: S/YL-PH/11), Lam Tsuen (Plan no.: S/NE-LT/11),
Kam Tin North (Plan no.: S/YL-KTN/9) and Kam Tin South (Plan no.: S/YL-KTS/15),
existing and planned ASRs including domestic premises, place for worship,
clinic and elderly centre within the assessment area are identified following
the requirement of Annex 12 of the EIAO-TM.
Representative
assessment points of the identified ASRs are selected for the air quality
impact assessment and are tabulated in Table 3.4.
Locations of the representative ASRs are shown in Figure 3.2. The
selected assessment points will represent the worst impact points due to the
Project having the shortest distances between the project boundaries and the
identified ASRs.
Table 3.4 Summary of the Identified
Representative ASRs
|
ASRs Code |
ASRs Descriptions |
No. of Storeys |
Max Height Above Ground (approx.) (m) |
Sensitive Use |
Distance from Works Boundary (approx.) (m) |
|
A1 |
Village house, Pang Ka Tsuen |
2 |
4.5 |
Residential |
5 |
|
A2 |
Dormitory of Shek Kong Barrack |
3 |
7.5 |
Residential |
<5 |
|
A3 |
Village house, 2A -2B Shek Kong San Tsuen |
3 |
7.5 |
Residential |
<5 |
|
A4 |
Village house near Seasons Villa |
2 |
4.5 |
Residential |
<5 |
|
A5 |
Village house near Shek Kong Vegetable
Station |
2 |
4.5 |
Residential |
<5 |
|
A6 |
Village house, Chung Ying Yuen, Wang Toi
Shan Tsoi Yuen Tsuen (North) |
2 |
4.5 |
Residential |
5 |
|
A7 |
Village house, Ching Yuen |
2 |
4.5 |
Residential |
<5 |
|
A8 |
Village house, Lee Ka Yuen, 27 Wang Toi
Shan San Tsuen |
2 |
4.5 |
Residential |
<5 |
|
A9 |
Village house, 28C Wang Toi Shan San Tsuen |
3 |
7.5 |
Residential |
<5 |
|
A10 |
Village house, Lodgewood, 72 Wang Toi Shan
San Tsuen |
3 |
7.5 |
Residential |
<5 |
|
A11 |
Village house, 50F Wang Toi Shan Yau Uk
Tsuen |
3 |
7.5 |
Residential |
<5 |
|
A12 |
Village house, 30 Wang Toi Shan Lo Uk Tsuen |
2 |
4.5 |
Residential |
<5 |
|
A13 |
Block 9, Evergreen International Hong Kong
Association |
3 |
7.5 |
Residential |
5 |
|
A14 |
Village house, 1 Wang Toi Shan Lo Uk Tsuen |
2 |
4.5 |
Residential |
5 |
|
A15 |
Village house, Fau Wan Court |
3 |
7.5 |
Residential |
5 |
|
A16 |
Village house near Pine Hill Villa |
2 |
4.5 |
Residential |
5 |
|
A17 |
Village house, Hang Yuen, 25B Sheung Tsuen |
1 |
1.5 |
Residential |
<5 |
|
A18 |
Village house, 7A Sheung Tsuen |
2 |
4.5 |
Residential |
<5 |
|
A19 |
Village house, Yiu Court, 6 Sheung Tsuen |
3 |
7.5 |
Residential |
<5 |
|
A20 |
Village house, 14A Sheung Tsuen |
2 |
4.5 |
Residential |
<5 |
|
A21 |
Sheung Tsuen Park |
1 |
1.5 |
Park |
<5 |
|
A22 |
Village house next to Pat Heung Sheung
Tsuen Village Office |
3 |
7.5 |
Residential |
10 |
|
A23 |
Village house, 4 Sheung Tsuen |
3 |
7.5 |
Residential |
5 |
|
A24 |
Village house, 3 Sheung Tsuen |
3 |
7.5 |
Residential |
5 |
|
A25 |
Village house, 9B Sheung Tsuen |
3 |
7.5 |
Residential |
5 |
|
A26 |
Site Office next to bus stop |
1 |
1.5 |
Residential |
<5 |
|
A27 |
Village house, 3A Wong Chuk Yuen |
1 |
1.5 |
Residential |
10 |
|
A28 |
Village house of Wong Chuk Yuen |
1 |
1.5 |
Residential |
10 |
|
A29 |
Village house next to Tai Hing Farm |
1 |
1.5 |
Residential |
<5 |
|
A30 |
Village house of Wong Chuk Yuen |
2 |
4.5 |
Residential |
10 |
|
A31 |
Village house, 151 Wong Chuk Yuen |
1 |
1.5 |
Residential |
10 |
|
A32 |
Village house, 70 Lam Kam Road |
1 |
1.5 |
Residential |
<5 |
|
A33 |
Lam Tsuen Country Park |
N/A |
N/A |
Country Park |
20 |
|
A34 |
Village house, opposite side of Kadoorie
Experimental Farm |
1 |
1.5 |
Residential |
30 |
|
P1(1) |
Planned Village Type Development [V Zone] at Kam Tin South OZP [Statutory Plan No.: S/YL-KTS/15] |
3* |
7.5 |
Residential |
5 |
|
P2(1) |
Village House of Wing Lung Wai (under
construction) |
2* |
4.5 |
Residential |
<5 |
|
P3(1) |
Planned Village Type Development (V Zone) at Kam Tin North OZP [Statutory Plan No.: S/YL-KTN/9] |
3* |
7.5 |
Residential |
15 |
|
P4(1) |
Planned Village Type Development (V Zone) at Kam Tin North OZP [Statutory Plan No.: S/YL-KTN/9] |
3* |
7.5 |
Residential |
<5 |
|
P5(1) |
Planned Residential Development (R(D) Zone) at Kam Tin North OZP [Statutory Plan No.: S/YL-KTN/9] |
2* |
4.5 |
Residential |
<5 |
|
P6(1) |
Planned Residential Development (R(C)2 Zone) at Kam Tin North OZP [Statutory Plan No.: S/YL-KTN/9] |
3* |
7.5 |
Residential |
<5 |
|
P7(1) |
Planned Village Type Development (V Zone) at Pat Heung OZP [Statutory Plan No.: S/YL-PH/11] |
3* |
7.5 |
Residential |
<5 |
|
P8(1) |
Planned village house [Planning Application Case No.: A/YL-PH/798] |
3** |
7.5 |
Residential |
<5 |
|
P9(1) |
Planned Residential Development (R(D) Zone) at Pat Heung OZP [Statutory Plan No.: S/YL-PH/11] |
2* |
4.5 |
Residential |
<5 |
|
P10(1) |
Planned residential development [Planning Application Case No.: A/YL-PH/736] |
2** |
4.5 |
Residential |
5 |
|
P11(1) |
Planned Village Type Development (V Zone)
at Shek Kong OZP [Statutory Plan No.: S/YL-SK/9] |
3* |
7.5 |
Residential |
<5 |
|
P12(1) |
Planned Village Type Development (V Zone)
at Shek Kong OZP [Statutory Plan No.: S/YL-SK/9] |
3* |
7.5 |
Residential |
<5 |
|
Notes: (1)The planned ASRs under the
Outline Zoning Plans will only be considered during operation phase * Permitted maximum building
height or number of storey stated in the approved Outline Zoning Plan ** Number of storey stated in
the planning application |
|||||
Three elevations are chosen for the assessment: 1.5m above local ground
level (which is the average height of the human breathing zone), 4.5m and 7.5m
above local ground level (mPD).
Fugitive
dust may be generated from works activities including site clearance,
excavation, handling of construction materials, concrete breaking and from
minor wind erosion. Each active
construction activity location shall occupy about 50m in length of the Project
alignment at any one time, and with a distance separation more than 600m
between each location. The area of
the work front would be about 500m2 (10m x 50m). Given that each
works area is small, dust impacts during the construction phases are
anticipated to be minor with the adoption of mitigation measures stipulated in
the Air Pollution Control (Construction Dust) Regulation. As such, a quantitative dust impact
assessment is not necessary.
In
addition, activities that may induce significant dust emissions such as
extensive site formation and blasting are not required for Project development.
Small
amount of SO2, NO2 and smoke shall be emitted from the
diesel-powered construction equipment. Under normal operation, however, such
properly maintained equipment shall not contribute any significant smoke or
gaseous emissions. According to the Air Pollution Control (Non-road Mobile
Machinery (NRMM) (Emission) Regulation, only approved or exempted NRMMs with a
proper label are allowed to be used in specified activities and locations
including construction sites. Considering the limited number of equipment to be
used in the site and the use of equipment in compliance with the Air Pollution
Control (Non-road Mobile Machinery (NRMM)) (Emission) Regulation, emissions
from construction equipment are considered relatively low and would not
anticipate to cause adverse air quality impact.
As
stated in Section 2, there is only one designated project within 500m of the
Project boundary (i.e., Development of Organic Resources Recovery Centre (ORRC)
(Phase 3)) and will potentially be constructing concurrently with this Project. As the EIA study of this concurrent project
is in progress, there is no detailed construction methods and programme can be
reviewed. The EIA study of this
concurrent project should take into account the potential cumulative impacts
arising from the Project. Nevertheless,
it is expected only minor local-scale dust impacts arising from the
construction activities of these projects are anticipated with proper
mitigation measures implemented on-site. As such, the cumulative dust impacts
as a result of concurrent works within the assessment area are not expected as
there is large distance separation between the Project site anjd the concurrent
projects; and provided that the recommended dust suppression measures are
implemented.
A site
inspection has been conducted in October 2018 to identify any chimneys within Project
assessment area. It is identified that no emission sources are located within Project
assessment area during the site inspection. Site survey route and observations are
shown in Figure 3.4.
Although no adverse construction
phase air quality impacts are anticipated, as a best practice measure to ensure
compliance with the Air Pollution Control (Construction Dust) Regulation, it is
suggested that the following control measures be incorporated into contract
documents:
·
Limitation of each active construction work front to occupy about 50m x
10m work area at any one time, and with a separation distance of more than 600m
between two concurrent work areas;
·
Works area for site clearance shall be sprayed with water before, during
and after the construction so as to maintain the entire surface wet;
·All dusty materials shall be sprayed with water
immediately prior to any loading, unloading or handling so as to maintain the
dusty materials wet;
·Hoarding of not less than 2.4 m above ground shall
be provided, as far as practicable, along the
site boundary which is next to the public areas;
·Restricting heights not higher than 1.5m above
ground from which materials are to be dropped,
as far as practicable to minimise the fugitive dust arising from
unloading/ loading;
·Any stockpile of dusty materials shall be covered
entirely by impervious sheeting; and/ or placed
in an area sheltered on the top and 4 sides;
·Immediately before leaving a construction site, all
vehicles shall be washed to remove any dusty materials from its body and
wheels; and
·Where a vehicle leaving construction site is
carrying a load of dusty materials, the load shall be covered entirely by clean
impervious sheeting to ensure that the dusty materials do not leak
from the vehicle.
No
adverse residual impacts are anticipated during the construction phase.
All
major roads within 500m of the assessment area were included in the model. The
hourly and annual average NO2, daily and annual average RSP, and
daily and annual average FSP at the selected ASRs have been calculated.
The
construction of the Project is planned to start by early of Year 2021 for
completion by the end of Year 2025. All the new roads proposed under the Project
shall also be completed by Year 2025. A sensitivity test has been conducted to
determine the worst-case assessment year and is presented in Appendix 3.1. Based
on the sensitivity test, Year 2025 was found to be the worst-case assessment
year within 15 years (Year 2025 to Year 2040) of the commencement of the
Project. The projected hourly traffic flows and vehicle compositions by the
Project traffic consultant for the Year 2025, Year 2030, Year 2035, and Year
2040 are provided in Appendix 3.2. The forecast traffic flow
and speed fraction as presented in Appendix 3.3 for Year 2025, Year 2030, Year
2035, and Year 2040 with 16 vehicle classes have been submitted to the
Transport Department (TD) for agreement. The agreement letter from TD on the
use of the projected traffic data for this study is also attached in Appendix 3.2.
Vehicular
emission comprises a number of pollutants, including NOx, RSP, FSP,
SO2, CO, Pb, etc. According to “An Overview on Air Quality and Air
Pollution Control in Hong Kong” published by EPD, one of the major air
pollution issues is the local street-level pollution. Diesel vehicles are the
main source of street-level pollution. The levels of NO2 at the
roadside in Hong Kong have been exceeding the Air Quality Objectives over the
years. Motor vehicles, especially diesel vehicles, are the main sources of
these pollutants at street level in Hong Kong.
CO is
one of the primary pollutants emitted by road transport. However, monitoring
results from all of the EPD’s air quality monitoring stations show that
background CO concentrations are well below the respective AQO criteria. CO is therefore considered to be
non-critical and it is not considered necessary to be quantitatively assessed. In
Hong Kong, vehicles are restricted to use Ultra Low Sulphur Diesel with a
sulphur content of less than 0.001%. Therefore, emission of SO2 from
vehicles is considered minor and no further assessment is considered necessary.
O3 is formed from photochemical reaction between NOx and
VOCs in the presence of sunlight. It is not a primary pollutant in vehicular
emissions and thus is not considered as a key criteria pollutant for this
Project. Leaded petrol has been banned in Hong Kong since 1999. As such, it is
not considered a critical air pollutant of concern and not necessary to be
further assessed.
As
discussed above, CO, SO2, ozone and lead are not considered as critical
pollutant of concern in this project. Thus, this report focuses on the NO2,
RSP and FSP concentrations due to vehicular emission on the surrounding air
sensitive receivers.
The
assessment of operation phase air quality impact has followed the detailed
technical requirements given in Appendix B of the EIA Study Brief. The
vehicular emission impact review has been carried out with the aid of the
Gaussian dispersion model “CALINE4” which is an EPD recommended software
package for dispersion modelling. Ozone Limiting Method (OLM) was adopted in
the modelling exercise for converting NOx to NO2.
Vehicular Emissions within
HKSAR
EMFAC-HK 4.1 model was adopted to
estimate the emission rates of 16 types of vehicles and inventories of exhaust
oxides of nitrogen and particulate matter for worst-case scenario (year 2025).
“EMFAC” mode was used for predicting the vehicular emission of 16 vehicle
classes with different speed profiles. The 16 vehicle classes are shown in
Table 3.5. The roads considered in
this Project and the corresponding traffic speed limits are provided in Table 3.6. Traffic data for the
road segments within the assessment area are provided in Appendix
3.2.
Table 3.5 Vehicle Classes in EMFAC-HK Model
|
Vehicle Class |
Description |
Fuel |
Gross Vehicle Weight (Tonnes) |
|
PC |
Private Cars |
ALL |
ALL |
|
TAXI |
Taxi |
ALL |
ALL |
|
LGV3 |
Light Goods Vehicles (<=2.5t) |
ALL |
<=2.5t |
|
LGV4 |
Light Goods Vehicles (2.5-3.5t) |
ALL |
>2.5-3.5t |
|
LGV6 |
Light Goods Vehicles (3.5-5.5t) |
ALL |
>3.5-5.5t |
|
HGV7 |
Medium & Heavy Goods Vehicles (5.5-15t) |
ALL |
>5.5-15t |
|
HGV8 |
Medium & Heavy Goods Vehicles
(>=15t) |
ALL |
>15t |
|
PLB |
Public Light Buses |
ALL |
ALL |
|
PV4 |
Private Light Buses (<=3.5t) |
ALL |
<=3.5t |
|
PV5 |
Private Light Buses (>3.5t) |
ALL |
>3.5t |
|
NFB6 |
Non-franchised Buses (<6.4t) |
ALL |
<=6.36t |
|
NFB7 |
Non-franchised Buses (6.4-15t) |
ALL |
>6.36-15t |
|
NFB8 |
Non-franchised Buses (>15t) |
ALL |
>15t |
|
FBSD |
Single Deck Franchised Buses |
ALL |
ALL |
|
FBDD |
Double Deck Franchised Buses |
ALL |
ALL |
|
MC |
Motor Cycles |
ALL |
ALL |
Table 3.6 Traffic speeds limits for the road sections
|
Road ID |
Road Section |
Traffic Speed Limit (km/hr) |
|
3, 5, 7, 9, 10, 27 |
Remaining sections of Kam Tin
Road |
50 |
|
11 |
Lam Kam Road |
50 |
|
11 |
A section of Kam Tin Bypass
(~40m in length within the assessment area) |
70 |
|
1, 2, 4, 6, 8, 12-26 |
Other road sections such as Fan
Kam Road, Kam Sheung Road, Route Twisk and Tung Wui Road etc. |
50 |
Vehicular
emission factors of each road section of each hour of a day were derived using
EPD’s EMFAC-HK v4.1 software. For
estimating the hourly vehicular emission factors, EMFAC model has been adopted
with the following assumptions:
· Ambient
temperature: 25oC
· Relative
humidity: 70%
· Traffic
speed
o
50km/hr for all roads within the assessment area
(except a portion of Kam Tin Bypass) at non-rush hour
o
70km/hr for the portion of Kam Tin Bypass at
non-rush and rush hour
o
28 km/hr for all roads within the assessment
area (except a portion of Kam Tin Bypass) at rush hour (7-9am, 5-8pm)
The
speed fraction adopted in EMFAC model is attached in Appendix 3.3 and the vehicle speed at
each road section is attached in Appendix 3.4.
The layout
of roads with index is shown in Appendix 2.1.
For all road sections included in
the Project, roadside parking is prohibited and there is no legal roadside
parking along these road sections. As such, it is reasonably assumed that no
cold start of vehicles in road sections within the assessment area under normal
circumstances.
Having
reviewed the temperature and humidity data from Hong Kong Observatory, the
lowest daily-mean temperature is 13.9 oC and the lowest mean
relative humidity is 69% in year 2018. A comparison of emission factor between
25 oC and 13.9 oC has been conducted to justify the
choice of temperature assumption. The temperature and humidity data in year
2018 from Hong Kong Observatory and the comparison results are shown in Appendix 3.8.
Based
on the results, it is observed that there is a possible uncertainty of 16.2% in
NO2 emission factor, and with no difference in RSP emission factor
and FSP emission factor. However, as it is not expected to have lowest
temperature and relative humidity throughout the year; and the result of predicted
air pollutant concentrations as shown in S.3.6.3 are far below the AQO
standard, it is confirmed that adoption of a typical temperature and relative
humidity of 25 oC and 70% in the assessment would not affect the
conclusion of compliance with AQO.
The
calculated vehicular emissions of NOx, RSP and FSP for different
vehicle classes for different road types for 24 hours are listed in Appendix 3.5.
Composite emission rates at each road sections are listed in Appendix 3.6.
Evaluation of Operation Air
Quality Impact
In
accordance with EPD’s “Guidelines on Assessing the 'TOTAL' Air Quality Impacts
(revised version on Mar 2013)”, emission sources could be classified into 3
categories as follows, depending on their distance from the concerned site:
· Primary
contributions: project induced;
·
Secondary contributions: pollutant-emitting
activities in the immediate neighbourhood.
For most local scale projects, any emission sources in an area within
500m radius of the project site with notable impacts should be identified and
included in an air quality assessment to cover the short-range contributions
using EPD’s approved local-scale Gaussian type model; and
·
Other contributions: pollution not accounted
for by the previous two. PATH-2016 (Pollutants in the Atmosphere and their
Transport over Hong Kong) model has been adopted to estimate future
concentrations.
PATH-2016
is a regional air quality model developed by EPD to simulate air quality over
Hong Kong against the Pearl River Delta (PRD) as background. PATH-2016 is set
up on a three-dimensional grid system with horizontal nesting. For EIA
applications, it simulates wind field, pollutant emissions, transportation and
chemical transformation and outputs pollutant concentrations over Hong Kong and
the PRD region at a fine grid size of 27 km, 9 km, 3 km and 1 km in both the
N-S and E-W direction. PATH-2016 model is used to quantify the background air
quality during the operation phase of the Project. Emission sources including
roads, marine, airports, power plants and industries within the Pearl River
Delta Economic Zone and Hong Kong are considered in the PATH-2016 model.
Details of the PATH-2016 Model and related emission inventory can be found in
EPD’s web site. As described in the revised “TOTAL’ Air Quality Guidelines, the
relevant outputs of the PATH systems are gridded meteorological and pollutant
concentration data every hour of the simulation period.
With
reference to EPD’s Guidelines on Choice of Models and Model Parameter, 1 year
of recent available hourly meteorological data including wind speed, wind
direction, ambient temperature, mixing height obtained from EPD’s PATH-2016
(Year 2010 Grid Cell where road sections laid within: 2946, 2947, 3046, 3047,
3146, 3147, 3245, 3246, 3247, 3345, 3346, 3347, 3445, 3446, 3545, 3546) was
adopted to drive the CALINE4 model.
PCRAMMET was applied to generate Pasquill-Gifford stability class for
the input to CALINE4 model based on the aforementioned meteorological data.
For
other contribution estimation, 1 year of recent available hourly emission data
including NOx and RSP is obtained from EPD’s PATH-2016 (Year 2020
Grid Cell where road sections laid within: 2946, 2947, 3046, 3047, 3146, 3147,
3245, 3246, 3247, 3345, 3346, 3347, 3445, 3446, 3545, 3546). PATH does not predict FSP, the
background daily and annual concentrations of FSP were predicted to be 75% of
RSP and 71% of RSP, respectively, according to EPD’s “Guidelines on the
Estimation of PM2.5 for Air Quality Assessment in Hong Kong”. The following
approach has been adopted for the operation phase cumulative air quality impact
assessment:
· Use a
regional air quality prediction model developed by EPD (PATH-2016) to quantify
the impacts from various pollution
sources.
· Use
Gaussian dispersion models i.e. CALINE4 for line sources (open road) to
quantify the air quality impacts.
·
The PATH-2016 model results have been added
to the sum of the CALINE4 model results sequentially on an hour-to-hour basis
to derive the short-term and long-term cumulative impacts at the ASRs. The
maximum hourly, daily and annual average results have then been calculated in
accordance with the Title 40, Code of Federal Regulations, US Environmental
Protection Agency (USEPA 40 CFR) Part 51 “Revision to the Guideline on Air
Quality Models, Version 2005”. The pollutant concentration predicted at an ASR
amongst the 8,760 hours (a year) have been ranked/ averaged to calculate the
cumulative impact. The number of
exceedances for each ASR has been counted and compared with the acceptance
values in the prevailing AQO criteria.
The
followings are other assumptions to be adopted in the CALINE4 model with
reference to EPD’s Guidelines on Choice of Models and Model Parameter:
· Surface
roughness: 1m
Ozone Limiting Method (OLM) has
been adopted for the conversion of NOx predicted from the CALINE4 model to NO2
based on the hourly O3 concentrations from EPD’s PATH-2016 (Year
2020 Grid Cell where road sections laid within: 2946, 2947, 3046, 3047,
3146, 3147, 3245, 3246, 3247, 3345, 3346, 3347, 3445, 3446, 3545, 3546). A tailpipe emission NO2/NOx
ratio of 28% according to the EPD’s Guidelines on Choice of Models and Model
Parameters has also been assumed.
The NO2/NOx conversion will be calculated as follows:
[NO2]pred = 0.28 ×
[NOx]pred + MIN {0.72 × [NOx]pred, or (46/48) × [O3]PATH}
Guided
by a Working Group consisting of experts in air quality modelling, PATH-2016
has gone through extensive testing. It was determined that PATH-2016’s output
of RSP concentrations should be adjusted as follows before being applied for
EIA to account for the limited information on pollutant emissions on a larger
scale:
• 10th
highest daily RSP concentration: add 26.5 μg/m3.
• Annual
RSP concentration: add 15.6 μg/m3
Referring
to Section 4.6.6 of this report, noise barriers are proposed as the direct
noise mitigation measure for the Project.
Noise barriers would be erected along roadside near some of the NSRs to
reduce noise impact. As the Project
does not involve re-alignment of existing road networks, no additional road
traffic, no change of vehicle composition and no change of vehicle travelling
speed would be imposed, the erection of noise barrier is not considered as an
emission source. Though, the
dispersion of air pollutants would be risen up to the tip of the noise barrier
from the road surface. Air quality assessment for scenario with noise barrier
has been conducted as comparison to the scenario without noise barrier. The
location of noise barriers can be referred to Figure 3.2.
Results
indicate that the 19th highest 1-hour average NO2, 10th
highest daily average RSP and FSP, and annual average NO2, RSP and
FSP concentrations at all representative ASRs under scenarios with and without
noise barrier would comply with the AQOs. Background air quality levels and
detailed results are listed in Appendix 3.7 and the cumulative and project-contributed
air pollutant concentrations for scenarios with and without noise barrier are
summarised in Table 3.8 and Table 3.9 respectively.
Table 3.8 Summary of
Assessment Results – Operation Phase (Without Noise Barrier)
|
ASR
ID |
Height
Above Local Ground (m) |
Concentrations
(µg/m3) |
|||||
|
NO2 |
RSP |
FSP |
|||||
|
19th
Highest 1-hour |
Annual |
10th
Highest Daily |
Annual |
10th
Highest Daily |
Annual |
||
|
Criteria |
200 |
40 |
100 |
50 |
75 |
35 |
|
|
A1 |
1.5 |
94.6 |
17.6 |
79.5 |
33.7 |
59.6 |
24.0 |
|
4.5 |
94.6 |
16.5 |
79.5 |
33.6 |
59.6 |
24.0 |
|
|
7.5 |
87.0 |
15.1 |
79.5 |
33.6 |
59.6 |
24.0 |
|
|
A2 |
1.5 |
96.8 |
20 |
80 |
33.8 |
60.1 |
24.5 |
|
4.5 |
93.1 |
17.7 |
79.9 |
33.7 |
60 |
24.7 |
|
|
7.5 |
89.8 |
15.6 |
79.7 |
33.6 |
59.8 |
24.2 |
|
|
A3 |
1.5 |
97.6 |
19.2 |
79.5 |
33.7 |
59.6 |
24.7 |
|
4.5 |
94.6 |
17 |
79.5 |
33.7 |
59.6 |
23.3 |
|
|
7.5 |
85.0 |
15.2 |
79.5 |
33.6 |
59.6 |
23.3 |
|
|
A4 |
1.5 |
121.6 |
21.6 |
81 |
34.4 |
60.9 |
23.3 |
|
4.5 |
102.0 |
15.9 |
80.9 |
34.2 |
60.7 |
23.2 |
|
|
7.5 |
85.0 |
13.8 |
80.8 |
34.1 |
60.6 |
23.2 |
|
|
A5 |
1.5 |
127.2 |
27.3 |
81.6 |
34.6 |
61.4 |
23.2 |
|
4.5 |
102.0 |
17.6 |
81 |
34.2 |
60.8 |
23.2 |
|
|
7.5 |
84.6 |
14.4 |
80.8 |
34.1 |
60.6 |
23.2 |
|
|
A6 |
1.5 |
86.1 |
13.8 |
80.6 |
34.1 |
60.4 |
23.8 |
|
4.5 |
86.1 |
13.3 |
80.6 |
34.1 |
60.4 |
23.9 |
|
|
7.5 |
81.1 |
12.5 |
80.6 |
34.1 |
60.4 |
24.0 |
|
|
A7 |
1.5 |
125.7 |
26.8 |
81.7 |
34.6 |
61.5 |
23.9 |
|
4.5 |
101.1 |
16.4 |
81 |
34.2 |
60.9 |
23.8 |
|
|
7.5 |
84.9 |
13.6 |
80.8 |
34.1 |
60.7 |
23.4 |
|
|
A8 |
1.5 |
79.9 |
17.8 |
77.3 |
32.7 |
58 |
23.1 |
|
4.5 |
77.7 |
15.1 |
77.1 |
32.7 |
57.9 |
23.2 |
|
|
7.5 |
75.9 |
13.1 |
77.1 |
32.6 |
57.8 |
23.1 |
|
|
A9 |
1.5 |
77.7 |
16.4 |
77.2 |
32.7 |
58 |
23.1 |
|
4.5 |
77.3 |
14.5 |
77.1 |
32.6 |
57.9 |
23.2 |
|
|
7.5 |
75.8 |
12.8 |
77.1 |
32.6 |
57.8 |
23.1 |
|
|
A10 |
1.5 |
77.7 |
16.2 |
77.2 |
32.7 |
57.9 |
23.1 |
|
4.5 |
77.3 |
14 |
77.1 |
32.6 |
57.9 |
23.2 |
|
|
7.5 |
75.4 |
12.6 |
77 |
32.6 |
57.8 |
24.4 |
|
|
A11 |
1.5 |
94.4 |
15.7 |
77 |
32.6 |
57.7 |
24.4 |
|
4.5 |
87.3 |
13.7 |
77 |
32.6 |
57.7 |
24.5 |
|
|
7.5 |
80.9 |
12.5 |
77 |
32.5 |
57.7 |
24.4 |
|
|
A12 |
1.5 |
84.7 |
14.8 |
77 |
32.6 |
57.7 |
24.5 |
|
4.5 |
82.9 |
13.4 |
77 |
32.6 |
57.7 |
24.2 |
|
|
7.5 |
78.6 |
12.4 |
77 |
32.5 |
57.7 |
24.0 |
|
|
A13 |
1.5 |
75.9 |
14.4 |
77.1 |
32.6 |
57.9 |
24.2 |
|
4.5 |
75.9 |
13.7 |
77.1 |
32.6 |
57.9 |
24.4 |
|
|
7.5 |
72.6 |
12.7 |
77.1 |
32.6 |
57.8 |
24.4 |
|
|
A14 |
1.5 |
84.9 |
14.1 |
77 |
32.6 |
57.7 |
24.0 |
|
4.5 |
84.4 |
13.2 |
77 |
32.6 |
57.7 |
23.4 |
|
|
7.5 |
79.8 |
12.5 |
77 |
32.5 |
57.7 |
23.3 |
|
|
A15 |
1.5 |
76.7 |
13.6 |
77.1 |
32.6 |
57.9 |
23.3 |
|
4.5 |
76.1 |
12.9 |
77.1 |
32.6 |
57.8 |
23.8 |
|
|
7.5 |
75.8 |
12.1 |
77.1 |
32.6 |
57.8 |
24.0 |
|
|
A16 |
1.5 |
73.9 |
12.1 |
80 |
33.4 |
60 |
23.3 |
|
4.5 |
72.6 |
11.9 |
80 |
33.4 |
60 |
24.0 |
|
|
7.5 |
70.6 |
11.6 |
80 |
33.4 |
60 |
24.0 |
|
|
A17 |
1.5 |
85.5 |
15.4 |
80.4 |
33.6 |
60.4 |
24.0 |
|
4.5 |
76.5 |
12.3 |
80.2 |
33.5 |
60.2 |
24.5 |
|
|
7.5 |
71.7 |
11.5 |
80.1 |
33.4 |
60.1 |
24.7 |
|
|
A18 |
1.5 |
105.0 |
18.6 |
80.6 |
33.7 |
60.6 |
24.2 |
|
4.5 |
79.0 |
12.2 |
80.1 |
33.5 |
60.1 |
24.7 |
|
|
7.5 |
70.4 |
11.5 |
80 |
33.4 |
60 |
23.3 |
|
|
A19 |
1.5 |
80.2 |
14.1 |
80.3 |
33.6 |
60.3 |
23.3 |
|
4.5 |
72.0 |
12.4 |
80.2 |
33.5 |
60.2 |
23.3 |
|
|
7.5 |
69.7 |
11.6 |
80.1 |
33.4 |
60.1 |
23.2 |
|
|
A20 |
1.5 |
78.4 |
13.9 |
80 |
33.5 |
60 |
23.2 |
|
4.5 |
73.9 |
12.5 |
80 |
33.5 |
60 |
23.2 |
|
|
7.5 |
72.6 |
11.6 |
80 |
33.4 |
60 |
23.2 |
|
|
A21 |
1.5 |
114.3 |
22.4 |
77.6 |
32.9 |
58.3 |
23.2 |
|
4.5 |
90.0 |
14.2 |
77.2 |
32.6 |
57.9 |
23.8 |
|
|
7.5 |
78.9 |
12.2 |
77 |
32.5 |
57.7 |
23.9 |
|
|
A22 |
1.5 |
79.6 |
13.2 |
77.1 |
32.6 |
57.9 |
24.0 |
|
4.5 |
77.1 |
12.5 |
77 |
32.5 |
57.8 |
23.9 |
|
|
7.5 |
77.1 |
11.8 |
77 |
32.5 |
57.8 |
23.8 |
|
|
A23 |
1.5 |
80.2 |
14 |
77.1 |
32.6 |
57.9 |
23.4 |
|
4.5 |
79.9 |
13.1 |
77 |
32.6 |
57.8 |
23.1 |
|
|
7.5 |
78.9 |
12.2 |
77 |
32.5 |
57.8 |
23.2 |
|
|
A24 |
1.5 |
79.6 |
12.5 |
77 |
32.5 |
57.8 |
23.1 |
|
4.5 |
79.6 |
12.1 |
77 |
32.5 |
57.8 |
23.1 |
|
|
7.5 |
79.6 |
11.7 |
76.9 |
32.5 |
57.7 |
23.2 |
|
|
A25 |
1.5 |
78.0 |
11.7 |
76.9 |
32.5 |
57.7 |
23.1 |
|
4.5 |
78.0 |
11.5 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
7.5 |
76.0 |
11.3 |
76.9 |
32.5 |
57.7 |
23.2 |
|
|
A26 |
1.5 |
96.2 |
14.9 |
77.1 |
32.6 |
57.9 |
24.4 |
|
4.5 |
82.5 |
12.3 |
76.9 |
32.5 |
57.7 |
24.4 |
|
|
7.5 |
78.0 |
11.6 |
76.9 |
32.5 |
57.7 |
24.5 |
|
|
A27 |
1.5 |
77.1 |
11.3 |
76.9 |
32.5 |
57.7 |
24.4 |
|
4.5 |
76.4 |
11.3 |
76.9 |
32.5 |
57.7 |
24.5 |
|
|
7.5 |
76.4 |
11.2 |
76.9 |
32.5 |
57.7 |
24.2 |
|
|
A28 |
1.5 |
71.4 |
11 |
76.9 |
32.5 |
57.7 |
24.0 |
|
4.5 |
71.4 |
11 |
76.9 |
32.5 |
57.7 |
24.2 |
|
|
7.5 |
71.4 |
11 |
76.9 |
32.5 |
57.7 |
24.4 |
|
|
A29 |
1.5 |
84.7 |
14.8 |
77.1 |
32.6 |
57.9 |
24.4 |
|
4.5 |
80.3 |
12.8 |
77 |
32.5 |
57.8 |
24.0 |
|
|
7.5 |
77.1 |
11.8 |
76.9 |
32.5 |
57.7 |
23.4 |
|
|
A30 |
1.5 |
65.9 |
10.8 |
82.4 |
34.4 |
61.8 |
23.3 |
|
4.5 |
65.9 |
10.7 |
82.4 |
34.4 |
61.8 |
23.3 |
|
|
7.5 |
65.9 |
10.7 |
82.4 |
34.4 |
61.8 |
23.8 |
|
|
A31 |
1.5 |
65.9 |
10.7 |
82.4 |
34.4 |
61.8 |
24.0 |
|
4.5 |
64.9 |
10.7 |
82.4 |
34.4 |
61.8 |
23.3 |
|
|
7.5 |
62.1 |
10.6 |
82.4 |
34.4 |
61.8 |
24.0 |
|
|
A32 |
1.5 |
73.7 |
13.1 |
82.6 |
34.4 |
62 |
24.0 |
|
4.5 |
72.3 |
12 |
82.5 |
34.4 |
61.9 |
24.0 |
|
|
7.5 |
69.4 |
11.2 |
82.4 |
34.4 |
61.8 |
24.5 |
|
|
A33 |
1.5 |
58.7 |
10.5 |
82.4 |
34.3 |
61.8 |
24.7 |
|
4.5 |
58.7 |
10.5 |
82.4 |
34.3 |
61.8 |
24.2 |
|
|
7.5 |
58.7 |
10.5 |
82.3 |
34.3 |
61.8 |
24.7 |
|
|
A34 |
1.5 |
71.6 |
12.6 |
82.5 |
34.5 |
61.9 |
23.3 |
|
4.5 |
69.3 |
11.3 |
82.4 |
34.4 |
61.9 |
23.3 |
|
|
7.5 |
65.9 |
10.9 |
82.4 |
34.4 |
61.8 |
23.3 |
|
|
P1 |
1.5 |
100.9 |
23.5 |
80 |
33.9 |
60.1 |
23.2 |
|
4.5 |
94.3 |
18.5 |
79.8 |
33.7 |
59.9 |
23.2 |
|
|
7.5 |
86.4 |
15.6 |
79.7 |
33.6 |
59.8 |
23.2 |
|
|
P2 |
1.5 |
89.8 |
17.6 |
79.9 |
33.7 |
60 |
23.2 |
|
4.5 |
88.3 |
16.4 |
79.8 |
33.7 |
59.9 |
23.2 |
|
|
7.5 |
86.2 |
15.3 |
79.7 |
33.6 |
59.8 |
23.8 |
|
|
P3 |
1.5 |
113.4 |
23.3 |
79.7 |
33.9 |
59.8 |
23.9 |
|
4.5 |
100.9 |
18.7 |
79.6 |
33.8 |
59.7 |
24.0 |
|
|
7.5 |
93.6 |
16 |
79.5 |
33.6 |
59.6 |
23.9 |
|
|
P4 |
1.5 |
142.5 |
29.8 |
79.8 |
34.2 |
59.9 |
23.8 |
|
4.5 |
113.4 |
18.9 |
79.6 |
33.7 |
59.7 |
23.4 |
|
|
7.5 |
95.8 |
16 |
79.5 |
33.6 |
59.7 |
23.1 |
|
|
P5 |
1.5 |
144.3 |
29.5 |
79.7 |
34.1 |
59.8 |
23.2 |
|
4.5 |
113.4 |
18.6 |
79.5 |
33.7 |
59.7 |
23.1 |
|
|
7.5 |
96.6 |
16 |
79.5 |
33.6 |
59.6 |
23.1 |
|
|
P6 |
1.5 |
95.5 |
17.4 |
79.5 |
33.7 |
59.6 |
23.2 |
|
4.5 |
94.6 |
16.3 |
79.5 |
33.6 |
59.6 |
23.1 |
|
|
7.5 |
88.5 |
14.9 |
79.5 |
33.6 |
59.6 |
23.1 |
|
|
P7 |
1.5 |
115.3 |
20 |
77 |
32.8 |
57.8 |
23.2 |
|
4.5 |
93.8 |
13.8 |
77 |
32.6 |
57.7 |
24.4 |
|
|
7.5 |
76.7 |
12.7 |
77 |
32.5 |
57.7 |
24.4 |
|
|
P8 |
1.5 |
98.2 |
16.6 |
77 |
32.7 |
57.7 |
24.5 |
|
4.5 |
91.4 |
13.8 |
77 |
32.6 |
57.7 |
24.4 |
|
|
7.5 |
79.1 |
12.6 |
77 |
32.5 |
57.7 |
24.5 |
|
|
P9 |
1.5 |
120.6 |
19 |
77 |
32.8 |
57.7 |
24.2 |
|
4.5 |
101.0 |
13.5 |
77 |
32.6 |
57.7 |
24.0 |
|
|
7.5 |
83.7 |
12.5 |
77 |
32.5 |
57.7 |
24.2 |
|
|
P10 |
1.5 |
80.0 |
13.9 |
80 |
33.5 |
60 |
24.4 |
|
4.5 |
73.9 |
12.5 |
80 |
33.5 |
60 |
24.4 |
|
|
7.5 |
69.1 |
11.6 |
80 |
33.4 |
60 |
24.0 |
|
|
P11 |
1.5 |
109.8 |
18.6 |
80.6 |
33.7 |
60.6 |
23.4 |
|
4.5 |
81.0 |
12.2 |
80.1 |
33.5 |
60.1 |
23.3 |
|
|
7.5 |
69.7 |
11.6 |
80 |
33.4 |
60 |
23.3 |
|
|
P12 |
1.5 |
117.6 |
21.3 |
77.7 |
32.9 |
58.4 |
23.8 |
|
4.5 |
94.6 |
14.1 |
77.2 |
32.6 |
57.9 |
24.0 |
|
|
7.5 |
79.6 |
12.4 |
77 |
32.5 |
57.8 |
23.3 |
|
Table 3.9 Summary of
Assessment Results – Operation Phase (With Noise Barrier)
|
ASR
ID |
Height
Above Local Ground (m) |
Concentrations
(µg/m3) |
|||||
|
NO2 |
RSP |
FSP |
|||||
|
19th
Highest 1-hour |
Annual |
10th
Highest Daily |
Annual |
10th
Highest Daily |
Annual |
||
|
Criteria |
200 |
40 |
100 |
50 |
75 |
35 |
|
|
A1 |
1.5 |
94.6 |
17.6 |
79.5 |
33.7 |
59.6 |
24.0 |
|
4.5 |
94.6 |
16.5 |
79.5 |
33.6 |
59.6 |
23.9 |
|
|
7.5 |
87.0 |
15.1 |
79.5 |
33.6 |
59.6 |
23.9 |
|
|
A2 |
1.5 |
95.8 |
20.0 |
80.0 |
33.8 |
60.1 |
24.0 |
|
4.5 |
93.1 |
17.7 |
79.9 |
33.7 |
60.0 |
24.0 |
|
|
7.5 |
89.8 |
15.6 |
79.7 |
33.6 |
59.8 |
23.9 |
|
|
A3 |
1.5 |
97.6 |
19.1 |
79.5 |
33.7 |
59.6 |
24.0 |
|
4.5 |
94.6 |
17.0 |
79.5 |
33.7 |
59.6 |
23.9 |
|
|
7.5 |
86.7 |
15.2 |
79.5 |
33.6 |
59.6 |
23.9 |
|
|
A4 |
1.5 |
121.0 |
21.5 |
81.0 |
34.4 |
60.9 |
24.5 |
|
4.5 |
102.0 |
15.9 |
80.9 |
34.2 |
60.7 |
24.3 |
|
|
7.5 |
85.0 |
13.9 |
80.8 |
34.1 |
60.6 |
24.2 |
|
|
A5 |
1.5 |
127.2 |
27.3 |
81.6 |
34.6 |
61.4 |
24.7 |
|
4.5 |
102.0 |
17.6 |
81.0 |
34.2 |
60.8 |
24.4 |
|
|
7.5 |
84.6 |
14.4 |
80.8 |
34.1 |
60.6 |
24.3 |
|
|
A6 |
1.5 |
86.1 |
13.8 |
80.6 |
34.1 |
60.4 |
24.2 |
|
4.5 |
86.1 |
13.3 |
80.6 |
34.1 |
60.4 |
24.2 |
|
|
7.5 |
81.1 |
12.5 |
80.6 |
34.1 |
60.4 |
24.2 |
|
|
A7 |
1.5 |
125.7 |
26.8 |
81.7 |
34.6 |
61.5 |
24.7 |
|
4.5 |
101.1 |
16.4 |
81.0 |
34.2 |
60.9 |
24.3 |
|
|
7.5 |
84.9 |
13.6 |
80.8 |
34.1 |
60.7 |
24.2 |
|
|
A8 |
1.5 |
79.9 |
17.3 |
77.3 |
32.7 |
58.0 |
23.3 |
|
4.5 |
77.7 |
15.0 |
77.1 |
32.7 |
57.9 |
23.2 |
|
|
7.5 |
75.9 |
13.1 |
77.1 |
32.6 |
57.8 |
23.2 |
|
|
A9 |
1.5 |
77.7 |
16.4 |
77.2 |
32.7 |
58.0 |
23.3 |
|
4.5 |
77.3 |
14.5 |
77.1 |
32.6 |
57.9 |
23.2 |
|
|
7.5 |
75.8 |
12.8 |
77.1 |
32.6 |
57.8 |
23.2 |
|
|
A10 |
1.5 |
77.7 |
16.2 |
77.2 |
32.7 |
57.9 |
23.3 |
|
4.5 |
77.3 |
14.0 |
77.1 |
32.6 |
57.9 |
23.2 |
|
|
7.5 |
75.4 |
12.6 |
77.0 |
32.6 |
57.8 |
23.1 |
|
|
A11 |
1.5 |
94.4 |
15.7 |
77.0 |
32.6 |
57.7 |
23.2 |
|
4.5 |
87.3 |
13.7 |
77.0 |
32.6 |
57.7 |
23.2 |
|
|
7.5 |
80.0 |
12.4 |
77.0 |
32.5 |
57.7 |
23.1 |
|
|
A12 |
1.5 |
84.4 |
13.8 |
77.0 |
32.6 |
57.7 |
23.2 |
|
4.5 |
80.0 |
13.2 |
77.0 |
32.6 |
57.7 |
23.2 |
|
|
7.5 |
79.9 |
12.5 |
77.0 |
32.6 |
57.7 |
23.1 |
|
|
A13 |
1.5 |
75.8 |
14.0 |
77.1 |
32.6 |
57.9 |
23.2 |
|
4.5 |
72.6 |
13.4 |
77.1 |
32.6 |
57.8 |
23.2 |
|
|
7.5 |
72.3 |
12.7 |
77.1 |
32.6 |
57.8 |
23.2 |
|
|
A14 |
1.5 |
84.9 |
14.0 |
77.0 |
32.6 |
57.7 |
23.2 |
|
4.5 |
84.4 |
13.2 |
77.0 |
32.6 |
57.7 |
23.2 |
|
|
7.5 |
79.8 |
12.5 |
77.0 |
32.5 |
57.7 |
23.1 |
|
|
A15 |
1.5 |
76.7 |
13.6 |
77.1 |
32.6 |
57.9 |
23.2 |
|
4.5 |
76.1 |
12.9 |
77.1 |
32.6 |
57.8 |
23.2 |
|
|
7.5 |
75.8 |
12.1 |
77.1 |
32.6 |
57.8 |
23.1 |
|
|
A16 |
1.5 |
73.9 |
12.1 |
80.0 |
33.4 |
60.0 |
23.8 |
|
4.5 |
72.6 |
11.9 |
80.0 |
33.4 |
60.0 |
23.8 |
|
|
7.5 |
70.6 |
11.6 |
80.0 |
33.4 |
60.0 |
23.7 |
|
|
A17 |
1.5 |
85.5 |
15.5 |
80.4 |
33.6 |
60.4 |
23.9 |
|
4.5 |
76.5 |
12.3 |
80.2 |
33.5 |
60.2 |
23.8 |
|
|
7.5 |
71.7 |
11.5 |
80.1 |
33.4 |
60.1 |
23.7 |
|
|
A18 |
1.5 |
105.0 |
18.6 |
80.6 |
33.7 |
60.6 |
24.0 |
|
4.5 |
79.0 |
12.2 |
80.1 |
33.5 |
60.1 |
23.8 |
|
|
7.5 |
70.4 |
11.5 |
80.0 |
33.4 |
60.0 |
23.7 |
|
|
A19 |
1.5 |
80.2 |
14.1 |
80.3 |
33.6 |
60.3 |
23.9 |
|
4.5 |
72.0 |
12.4 |
80.2 |
33.5 |
60.2 |
23.8 |
|
|
7.5 |
69.7 |
11.6 |
80.1 |
33.4 |
60.1 |
23.8 |
|
|
A20 |
1.5 |
78.4 |
13.9 |
80.0 |
33.5 |
60.0 |
23.8 |
|
4.5 |
73.9 |
12.5 |
80.0 |
33.5 |
60.0 |
23.8 |
|
|
7.5 |
71.7 |
11.6 |
80.0 |
33.4 |
60.0 |
23.8 |
|
|
A21 |
1.5 |
113.5 |
22.0 |
77.5 |
32.9 |
58.3 |
23.4 |
|
4.5 |
90.0 |
14.3 |
77.2 |
32.6 |
57.9 |
23.2 |
|
|
7.5 |
78.9 |
12.5 |
77.0 |
32.5 |
57.8 |
23.1 |
|
|
A22 |
1.5 |
79.6 |
13.1 |
77.1 |
32.5 |
57.9 |
23.1 |
|
4.5 |
77.1 |
12.4 |
77.0 |
32.5 |
57.8 |
23.1 |
|
|
7.5 |
77.1 |
11.8 |
77.0 |
32.5 |
57.8 |
23.1 |
|
|
A23 |
1.5 |
79.9 |
13.4 |
77.1 |
32.6 |
57.8 |
23.2 |
|
4.5 |
79.9 |
12.9 |
77.0 |
32.6 |
57.8 |
23.1 |
|
|
7.5 |
78.9 |
12.2 |
77.0 |
32.5 |
57.8 |
23.1 |
|
|
A24 |
1.5 |
79.6 |
12.3 |
77.0 |
32.5 |
57.8 |
23.1 |
|
4.5 |
79.6 |
12.0 |
77.0 |
32.5 |
57.8 |
23.1 |
|
|
7.5 |
79.6 |
11.6 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
A25 |
1.5 |
78.0 |
11.7 |
76.9 |
32.5 |
57.7 |
23.1 |
|
4.5 |
78.0 |
11.4 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
7.5 |
76.0 |
11.3 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
A26 |
1.5 |
96.2 |
14.8 |
77.1 |
32.6 |
57.9 |
23.2 |
|
4.5 |
82.0 |
12.3 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
7.5 |
77.1 |
11.6 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
A27 |
1.5 |
77.1 |
11.3 |
76.9 |
32.5 |
57.7 |
23.1 |
|
4.5 |
76.4 |
11.2 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
7.5 |
76.4 |
11.2 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
A28 |
1.5 |
71.4 |
11.0 |
76.9 |
32.5 |
57.7 |
23.1 |
|
4.5 |
71.4 |
11.0 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
7.5 |
71.4 |
11.0 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
A29 |
1.5 |
84.7 |
14.8 |
77.1 |
32.6 |
57.9 |
23.2 |
|
4.5 |
80.3 |
12.8 |
77.0 |
32.5 |
57.8 |
23.1 |
|
|
7.5 |
77.1 |
11.8 |
76.9 |
32.5 |
57.7 |
23.1 |
|
|
A30 |
1.5 |
65.9 |
10.8 |
82.4 |
34.4 |
61.8 |
24.4 |
|
4.5 |
65.9 |
10.7 |
82.4 |
34.4 |
61.8 |
24.4 |
|
|
7.5 |
65.9 |
10.7 |
82.4 |
34.4 |
61.8 |
24.4 |
|
|
A31 |
1.5 |
65.9 |
10.7 |
82.4 |
34.4 |
61.8 |
24.4 |
|
4.5 |
64.9 |
10.7 |
82.4 |
34.4 |
61.8 |
24.4 |
|
|
7.5 |
62.1 |
10.6 |
82.4 |
34.4 |
61.8 |
24.4 |
|
|
A32 |
1.5 |
73.7 |
12.8 |
82.6 |
34.4 |
62.0 |
24.5 |
|
4.5 |
71.6 |
12.0 |
82.5 |
34.4 |
61.9 |
24.5 |
|
|
7.5 |
69.4 |
11.2 |
82.4 |
34.4 |
61.9 |
24.4 |
|
|
A33 |
1.5 |
58.7 |
10.5 |
82.4 |
34.3 |
61.8 |
24.4 |
|
4.5 |
58.7 |
10.5 |
82.4 |
34.3 |
61.8 |
24.4 |
|
|
7.5 |
58.7 |
10.5 |
82.3 |
34.3 |
61.8 |
24.4 |
|
|
A34 |
1.5 |
71.6 |
12.6 |
82.5 |
34.5 |
61.9 |
24.5 |
|
4.5 |
69.3 |
11.3 |
82.4 |
34.4 |
61.9 |
24.5 |
|
|
7.5 |
65.9 |
10.9 |
82.4 |
34.4 |
61.8 |
24.4 |
|
|
P1 |
1.5 |
100.9 |
23.5 |
80.0 |
33.9 |
60.1 |
24.2 |
|
4.5 |
94.3 |
18.4 |
79.8 |
33.7 |
59.9 |
24.0 |
|
|
7.5 |
86.4 |
15.6 |
79.7 |
33.6 |
59.8 |
23.9 |
|
|
P2 |
1.5 |
89.8 |
17.6 |
79.9 |
33.7 |
60.0 |
24.0 |
|
4.5 |
88.3 |
16.4 |
79.8 |
33.7 |
59.9 |
23.9 |
|
|
7.5 |
86.2 |
15.2 |
79.7 |
33.6 |
59.8 |
23.9 |
|
|
P3 |
1.5 |
113.4 |
23.3 |
79.7 |
33.9 |
59.8 |
24.2 |
|
4.5 |
100.9 |
18.7 |
79.6 |
33.8 |
59.7 |
24.0 |
|
|
7.5 |
93.6 |
15.9 |
79.5 |
33.6 |
59.6 |
23.9 |
|
|
P4 |
1.5 |
142.3 |
29.6 |
79.8 |
34.1 |
59.9 |
24.4 |
|
4.5 |
115.0 |
19.0 |
79.6 |
33.7 |
59.7 |
24.0 |
|
|
7.5 |
96.6 |
16.6 |
79.5 |
33.6 |
59.7 |
23.9 |
|
|
P5 |
1.5 |
144.3 |
29.5 |
79.7 |
34.1 |
59.8 |
24.4 |
|
4.5 |
113.4 |
18.6 |
79.5 |
33.7 |
59.7 |
24.0 |
|
|
7.5 |
96.6 |
16.0 |
79.5 |
33.6 |
59.6 |
23.9 |
|
|
P6 |
1.5 |
95.5 |
17.3 |
79.5 |
33.7 |
59.6 |
24.0 |
|
4.5 |
94.6 |
16.3 |
79.5 |
33.6 |
59.6 |
23.9 |
|
|
7.5 |
88.5 |
14.9 |
79.5 |
33.6 |
59.6 |
23.9 |
|
|
P7 |
1.5 |
115.3 |
20.0 |
77.0 |
32.8 |
57.8 |
23.4 |
|
4.5 |
93.8 |
13.8 |
77.0 |
32.6 |
57.7 |
23.2 |
|
|
7.5 |
76.7 |
12.7 |
77.0 |
32.5 |
57.7 |
23.1 |
|
|
P8 |
1.5 |
97.8 |
16.6 |
77.0 |
32.7 |
57.7 |
23.3 |
|
4.5 |
91.4 |
13.8 |
77.0 |
32.6 |
57.7 |
23.2 |
|
|
7.5 |
79.1 |
12.5 |
77.0 |
32.5 |
57.7 |
23.1 |
|
|
P9 |
1.5 |
120.6 |
19.0 |
77.0 |
32.8 |
57.7 |
23.3 |
|
4.5 |
101.0 |
13.5 |
77.0 |
32.6 |
57.7 |
23.2 |
|
|
7.5 |
83.7 |
12.5 |
77.0 |
32.5 |
57.7 |
23.1 |
|
|
P10 |
1.5 |
80.0 |
13.9 |
80.0 |
33.5 |
60.0 |
23.8 |
|
4.5 |
73.9 |
12.5 |
80.0 |
33.5 |
60.0 |
23.8 |
|
|
7.5 |
69.1 |
11.6 |
80.0 |
33.4 |
60.0 |
23.7 |
|
|
P11 |
1.5 |
109.0 |
18.6 |
80.6 |
33.7 |
60.6 |
24.0 |
|
4.5 |
81.0 |
12.2 |
80.1 |
33.5 |
60.1 |
23.8 |
|
|
7.5 |
69.7 |
11.5 |
80.0 |
33.4 |
60.0 |
23.7 |
|
|
P12 |
1.5 |
103.6 |
18.8 |
77.5 |
32.7 |
58.2 |
23.3 |
|
4.5 |
110.2 |
21.1 |
77.7 |
32.9 |
58.4 |
23.4 |
|
|
7.5 |
99.4 |
15.8 |
77.3 |
32.7 |
58.1 |
23.2 |
|
Based
on the detailed results presented in Appendix 3.7, most
of the ASRs have greater air quality impact at height of 1.5m. To this end,
contours at 1.5m level for the cumulative 19th 1-hour and annual NO2
concentrations, and 10th highest 24-hour and annual RSP/FSP concentrations at
1.5m above local ground are plotted in Figures
3.3a-3.3l.
There
will not have any changes in traffic flow, composition and speed after the road
improvement works. However, due to the implementation of the noise barriers as
road traffic noise mitigation measures, there will be changes in pollutant
concentration levels at some ASRs which are located behind the noise barriers.
The changes would be equal to the difference between scenarios of with and
without noise mitigation measures. The comparison between scenarios with and
without noise mitigation measures is shown in Appendix 3.7.
For
those remaining road sections, it is anticipated that there is no noticeable
and quantifiable change in air quality in view of the fact that there will be
no change in traffic flow, composition and speed after the road improvement
works.
The
predicted representative air pollutants including NO2, RSP and FSP
at the worst-case assessment years would comply with AQOs. Hence, no specific
mitigation measures would be required during the operation phase of the Project.
No adverse residual air
quality impact is anticipated during the operation phase for the Project.
Environmental
monitoring and audit for potential dust impacts should be conducted during the
construction phase of the Project for checking compliance with the legislative
requirements. Details of the
monitoring and audit programme are contained in a stand-alone EM&A Manual.
No
adverse impact would be generated during the operation phase of this Project.
Therefore, the EM&A works related to air quality for the operation phase are
considered not necessary.
Construction Phase
Potential
air quality impacts from the construction works would be mainly due to
construction dust from excavation, materials handling and wind erosion. With
the implementation of recommended dust suppression measures as specified in
Section 3.5.3 on active construction works areas and including works areas and
mitigation measures specified in the Air
Pollution Control (Construction Dust) Regulation and EM&A programme. No exceedance of AQO is anticipated.
Operation Phase
Cumulative air quality
impact arising from the vehicular emissions from the open roads within the
assessment area has been assessed at the worst-case years. The assessment results conclude that the
predicted cumulative 19th highest hourly average and annual average NO2,
10th highest daily average and annual average RSP / FSP
concentrations at representative ASRs would comply with AQO.