2019-06-28_REVISION - M1977004 ‎(11)‎

• Permit No: M1977004
• IBM Index Class Name: REVISION
• Doc Date: 6/28/2019
• Doc Name: Request For Amendment To Permit
• From: Homestake Mining
• To: DRMS
• Type & Sequence: AM1
• Email Name: DMC
• Email Name: THM
• Media Type: D
• Archive: No

Homestake Mining Company May 10,2019
Regular(112d)Operation Reclamation Permit Application Package
TABLE OF CONTENTS
TABLEOF CONTENTS .........................................................................................................i
LISTOF TABLES.................................................................................................................iii
LISTOF FIGURES...............................................................................................................iii
LISTOF DRAWINGS............................................................................................................v
1.0 INTRODUCTION..........................................................................................................1
2.0 MINE DESCRIPTION...................................................................................................3
2.1. Mine Location..........................................................................................................3
2.2. Site History ..............................................................................................................3
2.3. Reclamation Plan and Technical Revision History..............................................4
2.4. Reclamation Summary............................................................................................7
2.4.1. General Earthworks ..............................................................................................7
2.4.2. Water Management and Treatment.................................................................... 11
3.0 SITE CONDITIONS....................................................................................................13
3.1. Geology..................................................................................................................13
3.1.1. Geologic Setting..................................................................................................13
3.1.2. Stratigraphy.........................................................................................................13
3.1.3. Geologic Structures ............................................................................................15
3.1.4. Seismic Hazard...................................................................................................17
3.1.5. Mineralization......................................................................................................20
3.2. Precipitation...........................................................................................................20
3.3. Groundwater and Surface Water.........................................................................22
3.3.1. Surface Water.....................................................................................................22
3.3.2. Shallow Groundwater and Seepage from Mine Features...................................23
3.3.3. Bedrock Groundwater.........................................................................................24
3.3.4. Water Balance and Uranium Mass Load ............................................................25
3.3.4.1. Sitewide Water Balance: Water Year 2014...............................................26
3.3.4.2. Estimated Uranium Mass Loads ...............................................................35
3.3.4.3. North Pit/Underground Mine Workings System ........................................37
3.3.4.4. Indian Rock Dump.....................................................................................37
3.3.4.5. Tie Camp Rock Dump...............................................................................38
3.4. Slope Movement....................................................................................................38
3.4.1. History of Slope Movement.................................................................................38
3.4.1.1. North Pit....................................................................................................40
3.4.1.2. South Pit....................................................................................................42
3.4.1.3. Tie Camp Rock Dump and Indian Rock Dump.........................................42
3.4.2. Slope Movement Monitoring Program ................................................................43
3.4.2.1. Surficial Mapping of Landslide Features...................................................43
3.4.2.2. Inclinometers.............................................................................................43
3.4.2.3. Survey Point Network................................................................................44
3.4.2.4. Photo Stations...........................................................................................45
EXHIBIT E-RULE 6.4.5(AMENDED RECLAMATION PLAN) Page i
HOMESTAKE MINING COMPANY