Prefeasibility Access Road Design-Revised
33
The cost of the magnesium chloride solution used in the referenced MnDOT
study was around $0.70/gallon.
MILLER CREEK WATER APPLICATION
INTENSITY
FOR DUST SUPPRESSION
Miller Creek Route is a 10.15mile route conists of an unpaved road.
TABLE 1
Unpaved Water Suppression
Rearranged to isololate i/t
i/t = (0.8*p*d)/100-C
Control of Fugitive Dust Sources, EPA-450/3-88-908, Eq. 3-2 (1988)
t = time between applications (h)
MILLER CREEK ROUTE -- ANNUAL
Control
Efficiency (%)
[C]
Hourly Daytime Evap.
Rate (mm/h)
[p]
1
Hourly Daytime
Traffic Rate
(passes/hr)
[d]
2
Application
Intensity
(L/m
2
-h)
[i]
Application
Intensity
(gal/ft
2
-h)
3
Application
Volume
(gallons/day)
4
50
7.47
0.58
0.07
0.0017
26,401
75
7.47
0.58
0.14
0.0034
52,803
90
7.47
0.58
0.35
0.0086
132,007
MILLER CREEK ROUTE -- SUMMER
5
Control
Efficiency (%)
[C]
Hourly Daytime Evap.
Rate (mm/h)
[p]
1
Hourly Daytime
Traffic Rate
(passes/hr)
[d]
2
Application
Intensity
(L/m
2
-h)
[i]
Application
Intensity
(gal/ft
2
-h)
3
Application
Volume
(gallons/day)
4
50
9.91
0.58
0.09
0.0023
35,022
75
9.91
0.58
0.18
0.0045
70,045
90
9.91
0.58
0.46
0.0113
175,112
50%
75%
90%
1
Hourly daytime evaporation rate [p] developed using guidance in EPA-450-3-88-908 as follows
Value
Unit
60 inches per year
1524 mm per year
0.0049 NA
0.0065 NA
7.47 mm/hr
9.91 mm/hr
3
Conversion from L/m
2
-h to gal/ft
2
-h assumes 1 gallon = 3.785 L, and 1m
2
= 10.76 ft
2
4
Application Volume per day considers the application intensity applied over the entire area of the road for 12 hours per day. The area of the road determined as
5
Summer conditions assumed May - December (245 days); Winter conditions assumed January - April (120 days)
Road Width
(ft)
Road Length
(Miles)
Road Length
(ft)
Area
(ft2)
24
10.15
53,592
1,286,208
AP-42, Figure 13.2.2-3, Mean Annual Class A Pan Evaporation Rate
Notes
25.4mm per inch
EPA-450/3-88-908, Eq. 3-2 supplemental info
Parameter
Type A Pan Evaporation, annual rate
Type A Pan Evaporation, hourly
Annual to Hourly Conversion Factor
Summer to Hourly Conversion Factor
Annual Average
EPA-450/3-88-908, Eq. 3-2 supplemental info
1
Daily vehicle passes based on traffic information provided by RER, See Table 2. This assumes that traffic is evenly distributed over 24 hours. Only RER traffic
considered; inclusion of other traffic may alter the amount of water necessary for control.
i = application intensity (L/m2)
WATER APPLICATION INTENSITY FOR DUST SUPPRESSION
C = 100 - (0.8*p*d*t) /i
→
C = average control efficiency (%)
p = potential average hourly daytime evaporation rate (mm/h)
d = average hourly daytime traffic rate (passes per hour)
Annual Weighted Daily Average - Application Volume Per Day
Type A Pan Evaporation, hourly
Summer Average
64,376
32,188
160,940
Type A Pan Evaporation, annual rate
