Prefeasibility Access Road Design-Revised
37
WARREN PEAK ESTIMATION OF UNPAVED ROAD EMISSIONS
k
a
b
PM
2.5
0.15
0.9
0.45
PM
10
1.5
0.9
0.45
PM
4.9
0.7
0.45
P = number of days in a year with at least 0.01 inch of preciptiation (assumed at 90 days per AP-42, Figure 13.2.2-1)
E=(k * (sL)
0.91
* (W)
1.02
) (1-P/4N)
AP-42, Section 13.2.1, Paved Road Emissions (January 2011)
Constants
k
PM
2.5
0.00054
PM
10
0.0022
PM
0.011
P = number of days in a year with at least 0.01 inch of preciptiation (assumed at 90 days per AP-42, Figure 13.2.1-2)
N = Number of days in the averaging period
Shift Bus
3 per day
OTR Truck/pups
8 per day
Supply Truck
3 per day
UNPAVED EMISSION FACTOR
Full
Empty
Avg
Shift Bus
2
9.75
7.25
8.5
OTR Truck/pups
3
58.5
20 39.25
Supply Truck
4
16.5
9.5
13
Fleet Average
5
27
1
EPA-450/3-88-908, Table 3-1 Typical Silt Content Values of Surface Material on Industrial and Rural Unpaved Roads (September 1988)
2
Shift bus weight taken from
for 25 passenger bus; full weight assumes 200 lb per passenger
3
Haul truck specifications provided by RER
4
Supply truck weight based on Ryder 26 ft box truck with a 33,000 gvw, up to 14,000 lb of load capacity
5
AP-42, Section 13.2.2 requires that the lb/vmt emission factor be prepared on a weighted fleet average; it should not be developed vehicle by vehicle
PAVED ROAD EMISSION FACTOR
Full
Empty
Avg
Shift Bus
2
9.75
7.25
8.5
Haul truck
3
58.5
20 39.25
Supply Truck
4
16.5
9.5
13
Fleet Average
5
27
2
Shift bus weight taken from
for 25 passenger bus; full weight assumes 200 lb per passenger
3
Haul truck specifications provided by RER
4
Supply truck weight based on Ryder 26 ft box truck with a 33,000 gvw, up to 14,000 lb of load capacity
5
AP-42, Section 13.2.1 requires that the lb/vmt emission factor be prepared on a weighted fleet average; it should not be developed vehicle by vehicle
PM
10
(lb/vmt)
PM
2.5
(lb/vmt)
5
5.38
1.38
0.14
Vehicle Type
Silt
Content
1
(%)
Vehicle Weight (tons)
PM
(lb/vmt)
W = mean vehicle weight (tons)
E = emission factor (lb/VMT)
Constants
k = constant based PMfraction (lb/VMT)
VMT = Vehicle Mile Traveled
ESTIMATION OF PAVED ROAD EMISSIONS
E = emission factor (lb/VMT)
k = constant based PMfraction (lb/VMT)
sL = road surface silt loading (g/m
2
)
s = surface material silt content (%)
a = constant based on PMfraction, unitless
W = mean vehicle weight (tons)
b = constant based on PMfraction, unitless
Vehicle Type
Silt
Content
1
(g/m
2
)
Vehicle Weight (tons)
PM
(lb/vmt)
PM
10
(lb/vmt)
PM
2.5
(lb/vmt)
1.5
0.43
0.09
0.02
1
AP-42, Table 13.2.1-1. Silt content represents an average "Ubiquitous Baseline" of 0.6 g/m
2
and the "Ubiquitous Winter Baseline Multiplier during months
with frozen preceptiation 2.4 g/m
2
.
