Construction Activity |
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(1) |
Materials Handling |
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(2) |
Rock Breaking |
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(3) |
Excavation |
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(4) |
Vehicle Movements on Unpaved Site Roads |
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(5) |
Wind Erosion |
(1) Materials Handling (Based on USEPA AP-42 Vol. 1 5th Edition, Section 13.2.4.3)
where E = emission factor in kilograms per Megagram (Mg)
k = particle size multiplier
u = wind speed in metres per second
M = material moisture content in percent
Assumptions : (i) k = 0.74 for TSP
(ii) moisture content of 4.8%
(iii) daily handling = 164m3
(iv) density of spoil = 1800 kg/m3
(v) 10 working hours per day
(vi) mean wind speed = 4 m/s
= 7.56 x 10-4 kg/Mg
(2) Rock Breaking (Based on USEPA AP-42 Vol. 1 5th Edition, Table 11.9-2, Equation (1))
E (in kg/blast) = 0.00022 x (A)1.5
where A = Horizontal area (m2), with blasting depth ≤ 21m not for vertical face of a bench
E (in kg/vol. of produced material) = 0.00022 x (V/21)1.5/V
E (in kg/hr) = [0.00022 x (V/21)1.5/V (kg/vol. of produced material)] x V/H
H = 10 working hours per day
Assumption : V (Typical volume of material produced from rock breaking per day (m3) = 51
E = 0.00022 x (51/21)1.5 x (1/10) kg/hr
= 8.32 x 10-5 x 1000/(60x60) g/s
= 2.3 x 10-5 g/s
(3) Excavation (Based on USEPA AP-42 Vol. 1 5th Edition, Section 13.2.4.3)
where E = emission factor in kilograms per Megagram (Mg)
k = particle size multiplier
u = wind speed in metres per second
M = material moisture content in percent
Assumptions : (i) k = 0.74 for TSP
(ii) moisture content of 4.8%
(iii) mean wind speed = 4 m/s
(iv) max. excavation rate = 75 Mg/hr/excavator
(v) no. of excavator involved = 1
= 7.56 x 10-4 kg/Mg
= 7.56 x 10-4 kg/Mg x 75 Mg/hr/excavator x 1000 x 1/3600 x 1
= 0.01575 g/s
(4) Vehicle movements on unpaved site roads (Based on USEPA AP-42 Vol. 1 5th Edition, Section 13.2.2)
where E = Size-specific emission factor (lb/VMT)
S = surface material silt content (%)
W = mean vehicle weight (tons)
M = surface material moisture content (%)
Assumptions: (i) k = 10, a = 0.8, b = 0.5, c= 0.4 for TSP
(ii) surface material silt content of 4.3% (mean value from AP-42 Table 11.9-3 for haul truck)
(iii) surface material moisture content of 2.4% (mean value from AP-42 Table 11.9-3 for haul truck)
(iv) mean vehicle weight = 24 tons
(v) truck flow = 8 veh/hr
(vi) average one-way travel distance within site = 0.1km
(vii)1 lb/VMT = 281.9g/VKT
(viii) mean vehicle speed = 5 mph
= 4.61 lb/VMT
= 0.096 g/s
B.1.1. Unmitigated Scenario - Dust Emission Factor for Works Site for Stream Diversion
Total Site Area = 6200m2
(I) Total daytime TSP emissions = + (5)
= + 2.695 x 10-6
= 6.6 x 10-5 g/m2/s
(II) Nighttime TSP emissions = 2.695x10-6 g/m2/s
Assumption : 30% of the entire site as close to the nearest receptor to be exposed active works area