2008-04-15_REVISION - M1980244 ‎(274)‎

• Permit No: M1980244
• IBM Index Class Name: REVISION
• Doc Date: 4/15/2008
• Doc Name: County Vol 1 Attachment 10
• From: CC &V
• To: DRMS
• Type & Sequence: AM9
• Media Type: D
• Archive: No

•
EXPECTED OFF-SITE IMPACTS ......................................................................15
ATTACHMENT A, CALCULATION METHODS ................................................17
ATTACHMENT B -SEDCAD RESULTS OF ROUTING ................................... 20
ATTACHMENT C -SEDCAD POND GEOMETRY ........................................... 21
TABLES
Table I Summary of Runoff Volume, Design Volume, and Approximate Dimensions of
EMP ponds ......................................................................................................................11
FIGURES
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Figure 1 -East Cresson Storm Water Management Schematic, During Operations ........7
Figure 2 -Storm Water Management for West Side of Mine, During Operations .............7
Figure 3 -East Cresson and Wildhorse Storm Water Mangement after Closure ..............9
Figure 4 -Storm Water Management after Closure, West Side North of Squaw Gulch....9
Figure 5 -Residence Time and Settling Efficiency of EMPs ...........................................14
Figure 6 Riprap Size as Function of Slope and Shields Shear Stress ............................19
ATTACHMENT B INCLUDES THE FOLLOWING INFORMATION
Structure Network, Sub-watershed Details, and Sub-watershed Tc for East Cresson OSA
Structure Network and Sub-watershed Hydrology for North Cresson and Poverty Gulch
Structure Network and Sub-watershed Hydrology for Squaw Gulch OSA