2013-02-25_PERMIT FILE - C1982057A

• Permit No: C1982057A
• IBM Index Class Name: Permit File
• Doc Date: 2/25/2013
• Section_Exhibit Name: Tab 20 Backfilling and Grading
• Media Type: D
• Archive: Yes

TAB 20
TABLE OF CONTENTS
LIST OF FIGURES
Figure No. Page
20 -1 Postmining Topography Typical Mass Balance 9
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 8
20 -2 Postmine Drainage Channel Summary 13
20 -3 Guide to Retardance Class Selection 15
20 -4 Turf Reinforcement Mat Performance Guide 17
TR- 79 i Revised 12/12
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
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 8
20 -2 Postmine Drainage Channel Summary 13
20 -3 Guide to Retardance Class Selection 15
20 -4 Turf Reinforcement Mat Performance Guide 17
TR- 79 i Revised 12/12