2017-03-10_REVISION - C1981041

• Permit No: C1981041
• IBM Index Class Name: Revision
• Doc Date: 3/10/2017
• Doc Name: Application
• From: Snowcap Coal Company
• To: DRMS
• Type & Sequence: SL10
• Email Name: JHB
• Email Name: JRS
• Media Type: D
• Archive: No

LS (length and percent slope) factors account for the length and percent slope. These factors are taken
from Figure 4 of this document. Length of slope begins at the top of the micro watershed. This is usually at
the top of a hill, ridge, terrace or diversion. The length of slope is considered to end for a given field at one
of the following places: (1) the point where the slope decreases to the extent that deposition occurs, (2)
the point where runoff enters a well-defined channel, terrace or diversion , or (3) where water leaves the field.
The LS for the Reclaimed Areas are defined by the length and slope gradient within the disturbed area.
LS factors for the adjacent areas are drawn immediately adjacent to the disturbed area boundary for
the reclaimed areas.
Adjacent Area Pond 11 - LS Factor
The LS factor for the Adjacent area is based on an average 29H:1 V Slope and an average
change in elevation of 5 feet and average length of slope of 145 feet based on one flow line located in the
adjacent area.
Average Length 145.0 Feet
Average Slope 3.4%
Percent Slope (S)
3.0% 3.4% 4.0%
140 0.320 0.376 0.460
145.0 1 "LS" Factor 0.378
150 0.320 0.380 0.470
Reclaimed Pond 11 - LS Factor
The LS factor for the Pond 11 Area is based on an average 70H: 1V slope at an average change in
elevation of 4.75 feet and average length of slope of 335' based on two flow lines cut through the reclaimed an
Average Length 335.0 Feet
Average Slope 1.4%
Percent Slope (S)
1.0% 1.4% 2.0%
300 0.180 0.220 0.280
335.0 1 "LS" Factor 0.228
400 0.200 0.244 0.310
Adjacent Area - G Substation - LS Factor
The LS factor for the Adjacent area is based on an average 5.8H:1V Slope and an average
change in elevation of 34 feet and average length of slope of 196 feet based on two flow lines located in the
adjacent area.
Average Length 196.0 Feet
Average Slope 17.4%
Percent Slope (S)
16.0% 17.4% 18.0%
180 4.000 4.350 4.500
196.0 1 "LS" Factor 4.630
200 4.000 4.700 5.000
Reclaimed G Substation - LS Factor
The LS factor for the G Substation area is based on an average 5.75H: 1V slope and an average change in
elevation of 16.0 feet and average length of slope of 92' based on two flow lines cut through the reclaimed are:
Average Length 92.0 Feet
Average Slope 17.4%
Percent Slope (S)
16.0% 17.4% 18.0%
80 2.600 2.880 3.000
92.0 1 "LS" Factor 3.126
100 2.800 3.290 3.500
SL -10 Tab -7, Page 5 03/06/2017