2017-08-15_PERMIT FILE - C1980007A ‎(3)‎

• Permit No: C1980007A
• IBM Index Class Name: Permit File
• Doc Date: 8/15/2017
• Section_Exhibit Name: Exhibit 66 Mine Water Control Plan
• Media Type: D
• Archive: Yes

West Elk Mine - Mine Water Control Plan Mountain Coal Company
3.4.4 Particle Size Distribution
SEDCAD+ requires the particle size distribution of the erodible material be entered. Four
particle size distributions, obtained from previous modeling, were used in the SEDCAD+
analysis. At the main mine site, soils were distinguished between silt loam (most of the site),
river alluvium, and coal product. A single distribution was used within Sylvester Gulch, where
no significant alluvium or coal stockpiles exist.
Tetra Tech October 2010 6