PERMFILE54019

• Permit No: C1981022
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: EAST YARD POND DESIGN CALCULATIONS
• Section_Exhibit Name: Exhibit 2.05-E3 SECTION 1
• Media Type: D
• Archive: No

•
Subject Protection of the
Hydrologic System
Somerset Coal Mine -Elk Creek
East Storage Yard and Access Road
General Data:
CALCULATION NOTES
gy M. O. Anderson
Checked
Acct
October 23 19 79
Sheet No. 3 of 5 Sheets
Hydrologic Soil Glass "B"
Rainfall 1.90" for 10-year Z4-hour Storm
Hydrologic Soil Maps with CN - 3 Maps by U. S. S.
Access Road -East of Storaee Yard
100 Scale Map Area = 1.25°~ x 0. 2295684 0. 287 Acres
No runoff from Hillside - CN 47 -from AMC-II Storm Potential
AMG-II Potential
CN 82 =dirt roads - B-Soil (Table 9. 1, S. G.S. N. E. N. -Hydrology)
GN 82 S - 2. 20" x . 2 = 0. 44 (Table 10. 1, S. C. S. N. E. N. Hydrology)
x . 8 = 1.76

i
I
i
I

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I
i
Runoff: Q = (P - . 25) _ (1.90 - 0.44) = Z. 1316 = 0. 582"
P + . 85 1.90 + 1. 76 3. 66
Volume of runoff:
0. Z87 acres x SSZ" T 12 - 0. 0139 acre-feet
43560 x .0139195 = 606. 33 cubic feet
AMC-I Potential
CN82 (AMC-II) = CN66 (AMC-I) (Table 10. 1, S. C. S. N, E. N. Hydrology)
S - 1000 - 10 = 1000 - 10 = S. 15 x . Z = 1.03
CN' 66 x.8= 4.IZ
i
Runoff: Q = (1. 9 - 1.03) = 0. 7569 = 0. 12573"
1 . 9 + 4. 1 Z 6. OZ
Volume of runoff:
0.287 Ac. x . 1257 T 12 = 0. 0030 acre-feet
43560 x .003007 = 130. 98 cubic-feet
B-37