2009-10-05_PERMIT FILE - C1982057A ‎(2)‎

• Permit No: C1982057A
• IBM Index Class Name: Permit File
• Doc Date: 10/5/2009
• Section_Exhibit Name: Tab 20 Backfilling and Grading
• Media Type: D
• Archive: Yes

TAB 20
TABLE OF CONTENTS
Page
Disturbed Area 1
Backfilling and Grading Procedures 2
Postmining Topography 5
General 5
Volume Calculations (Premining Topography) 6
Premining Material Volume 6
Virgin Overburden Material Volume 6
Total In-Place Coal Volume 6
Recoverable Coal Volume 6
Premining Overburden Volume 6
Total Pit Spoil Volume 10
Volume Calculations (Postmining Topography) 10
Postmining Drainage Channel Design 11
Postmining Drainage Channels in the South Area 14
Vegetated Channel Designs 14
Rock Riprap Channel Design 16
Turf Reinforcement Mat Channel Deign 16
Permanent Structures 18
References Cited 19
LIST OF FIGURES
Figure No. Page
20-1 Postmining Topography Typical Mass Balance 9
20-2 Typical Runoff Control Structure 19
LIST OF TABLES
Table No. page
20-1 Postmining Landform Mass Balance (North Area) 7
20-1A Postmining Material Mass Balance - II-W South Area g
20-2 Postmine Drainage Channel Summary 13
20-3 Guide to Retardance Class Selection 15
20-4 Turf Reinforcement Mat Performance Guide 17

TR- 67 i Revised 08/09