2018-12-11_PERMIT FILE - C1981008A

• Permit No: C1981008A
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2018
• Doc Name: Mine Facilities
• Section_Exhibit Name: Section 2.05.3‎(3)‎ Table of Contents & Mine Facilities
• Media Type: D
• Archive: Yes

Table 2.05.3(3)-lA
Curve Numbers from October 1, 2015 to Present
Reclaimed Areas:
Topsoiled and seeded' Poor 83
Topsoil Stockpiles' Poor 80
1-2 years revegetation2 Fair 74
3+ years revegetation3 Good 62
Source: Part 630 Hydrology, National Engineering Handbook, Chapter 9 (USDA/NSCS, July 2004)
1. Curve number based on an average of "Fallow, with Crop Residue, Poor Condition", Table 9-1,
with 50% HSG A and 50% HSG B and conservatively revised upward.
2. Curve number based on an average of "Pasture or Range, Fair Condition', Table 9-1, with 50%
HSG A and 50% HSG B and conservatively revised upward.
3. Curve number based on an average of "Pasture or Range, Good Condition', Table 9-1, with 50%
HSG A and 50% HSG B conservatively revised upward.
Section 2.05.3(3) Page 9 April 2017 (MR -104)
Hydrologic
Curve
Condition
Number
Mine Disturbed Areas:
Newly Graded Areas'
Poor
83
Roads
N/A
85
Reclaimed Areas:
Topsoiled and seeded' Poor 83
Topsoil Stockpiles' Poor 80
1-2 years revegetation2 Fair 74
3+ years revegetation3 Good 62
Source: Part 630 Hydrology, National Engineering Handbook, Chapter 9 (USDA/NSCS, July 2004)
1. Curve number based on an average of "Fallow, with Crop Residue, Poor Condition", Table 9-1,
with 50% HSG A and 50% HSG B and conservatively revised upward.
2. Curve number based on an average of "Pasture or Range, Fair Condition', Table 9-1, with 50%
HSG A and 50% HSG B and conservatively revised upward.
3. Curve number based on an average of "Pasture or Range, Good Condition', Table 9-1, with 50%
HSG A and 50% HSG B conservatively revised upward.
Section 2.05.3(3) Page 9 April 2017 (MR -104)