Fort Knox Mine Reclamation and Closure Plan - Alaska Department

143 Pages·2006·38.01 MB·English

RECLAMATION

&
CLOSURE PLAN

prepared by

Fairbanks Gold Mining, Inc.
(a subsidiary of Kinross Gold Corporation)
PO Box 73726
Fairbanks, Alaska 99707-3726
[phone]

June 19, 2006
FORT KNOX MINE

RECLAMATION AND CLOSURE PLAN

Submitted to:

Alaska Department of Natural Resources
Division of Mining, Land and Water
3700 Airport Way
Fairbanks, Alaska 99709

Alaska Department of Environmental Conservation
Division of Air and Water Quality
610 University Avenue
Fairbanks, Alaska 99709-3643

and

Department of the Army
U.S. Army Engineer District, Alaska
P.O. Box 6898
Elmendorf AFB, Alaska 99506-6898

Submitted by:

Fairbanks Gold Mining, Inc.
A Subsidiary of Kinross Gold Corporation
P.O. Box 73726
Fairbanks, Alaska 99707-3726

June 19, 2006
Fort Knox Reclamation & Closure Plan June 19, 2006

TABLE OF CONTENTS
LIST OF FIGURES vii
LIST OF TABLES viii
APPENDICES ix
LIST OF ABBREVIATIONS x
TSF – Tailing Storage Facility x
1.0 INTRODUCTION 1
1.1 Purpose 1
1.2 Applicant Information 2
Fairbanks Gold Mining, Inc. Officer Completing Application 2
Designated Contact Person 2
Kinross Gold Corp. Information 2
Alaska Registered Agent 3
1.3 Location and Land Status 3
1.4 History of Fort Knox Mine 7
2.0 PROJECT DESCRIPTION 8
2.1 Existing Facilities and Conditions 8
Mill Facilities 8
Tailing Storage Facility 9
Decant Water 10
Seepage Water 11
Water Reservoir 12
Walter Creek Heap Leach Facility 12
2.2 General Environmental Information 14
Geology 15
Climate 15
Vegetation, Soils and Permafrost 15

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Fort Knox Reclamation & Closure Plan June 19, 2006

Surface Water 16
Groundwater 17
Alluvium 17
Bedrock 18
Background Water Chemistry 18
3.0 FORT KNOX WETLANDS 19
3.1 Jurisdictional Wetland Survey 19
3.2 Department of the Army Section 404 Permit 20
3.3 Fish Creek Valley Developed Wetlands Delineation 20
3.4 Developed Wetlands Functional Analysis 23
3.5 Heap Leach Wetland Impacts 24
3.6 Fishery Development and Enhancement 28
4.0 SURFACE DISTURBANCE AND LAND USE 28
4.1 Surface Disturbance 28
Placer and Other Mining Disturbances as of August 1992 28
Reclamation of Pre-Mining Disturbances 29
Fort Knox Mine Disturbance 29
4.2 Land Use 29
Land Use Prior to Fort Knox 29
Land Use During Fort Knox Operation 30
Post-Mining Land Uses 30
5.0 RECLAMATION PRACTICES 31
5.1 Schedule of Reclamation Activities 32
Reclamation Schedule 32
Reclamation of Construction Sites 34
Concurrent Reclamation 34
Final Reclamation 36
Temporary Closure 36

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Fort Knox Reclamation & Closure Plan June 19, 2006

5.2 General Reclamation Procedures 37
Earthwork 37
Control of Sedimentation 37
Growth Media 37
Seedbed Preparation 38
Fertilizer and Fertilization 39
Seed and Seeding 39
Revegetation Timing 40
Fort Knox Vegetative Restoration Studies 40
Revegetation Cover Criteria 40
5.3 Post-Mining and Post-Reclamation Topography 41
Drainage 41
Figure 5.2 Pre-development Ground Conditions at the Fort Knox Mine 42
Pit Slope Stability 45
Acid Rock Drainage (ARD) Potential 45
5.4 Public Access 48
6.0 FACILITY SPECIFIC RECLAMATION AND CLOSURE 48
6.1 Water Management 49
Receiving Water Beneficial Use 49
Mine Site Surface Water 49
Summary Water Management Strategy 50
6.2 Tailing Storage Facility Reclamation & Closure 51
Closure Sequence 53
Tailings Surface 54
Tailing Spillway 56
Wetland Treatment System 56
Tailings Embankment 58
6.3 Seepage Interception System 58
6.4 Pit Lake 59
6.5 Heap Leach Closure 60
Heap Leach Closure Procedures And Schedule 61
Residual Leaching 61

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Fort Knox Reclamation & Closure Plan June 19, 2006

Solution Recirculation/Rinsing 61
Release Of Draindown To The Tailing Impoundment 62
Release of minor long-term seepage to the tailing impoundment 62
Regrading and cover 62
6.6 Water Supply Reservoir, Solo Creek Causeway and Gil Causeway 62
6.7 Roads 64
6.8 Open Pit / Melba Monte Cristo Causeway 64
6.9 Waste Rock Dumps 65
6.10 Building and Equipment Sites 66
6.11 Wells and Well Closure 67
6.12 Miscellaneous Sites 67
Fence Removal 67
Electrical Power Facilities 67
Material Borrow Areas 68
7.0 MONITORING 69
7.1 Tailing Impoundment 69
Water Level Monitoring 73
Inspection of Surface Stabilization 73
7.2 Heap Leach 73
7.3 Long-Term Maintenance and Monitoring 76
Long-term Monitoring 76
Long-term Maintenance 76
8.0 APPLICANT STATEMENT OF RESPONSIBILITY 77
9.0 ESTIMATE OF RECLAMATION AND CLOSURE COSTS 78
9.1 Reclamation Cost Estimates and Financial Assurance Adjustment 78

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Fort Knox Reclamation & Closure Plan June 19, 2006

9.2 Agreement for Funding Post-Reclamation Obligations 79
10.0 ACKNOWLEDGEMENTS 80
11.0 REFERENCES 81

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Fort Knox Reclamation & Closure Plan June 19, 2006

LIST OF FIGURES

Figure 1.0 Fort Knox Mine Site Location Map 4
Figure 1.1 Fort Knox Mine Site General Arrangement 5
Figure 1.2 Upland/Millsite Permit Areas 6
Figure 3.0 Summary of Wetland Functional Scores 25
Figure 3.1 Comparison of Functional Scores Subtotals and Total 26
Figure 3.2 Heap Leach and Jurisdictional Wetlands 27
Figure 5.0 Schedule of Reclamation Activities 33
Figure 5.1 Fort Knox Growth Media Stockpiles 35
Figure 5.2 Pre-mining Topography 42
Figure 5.3 Post-Mining Topography 43
Figure 5.4 Post-Reclamation Topography 44
Figure 5.5 Cross-Section of Final Pit 46
Figure 5.6 Plan View of Final Pit 47
Figure 6.1 ADEC Solid Waste Disposal Permit Boundary 52
Figure 6.2 Plan View of Tailing Reclamation and Revegetation Map 55
Figure 6.3 Plan View of Wetland Treatment System 57
Figure 6.4 Fort Knox Water Reservoir Recreation Area 63
Figure 6.5 Fort Knox Groundwater Well Location Map 68
Figure 7.0 Water Monitoring Locations 70

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Fort Knox Reclamation & Closure Plan June 19, 2006

LIST OF TABLES

Table 2.0 Comparison of Decant Pond and Seepage Water 12
Table 3.0 Jurisdictional Wetlands Summary 1992 19
Table 3.1 Jurisdictional Wetlands Breakdown 1992 20
Table 3.2 Mitigation Requirements of the TSF Required by 404 Permit 20
Table 3.3 Comparison of Acres Created/Enhanced/404 Mitigation 22
Table 3.4 Summary of Wetland and Open Water Acres to be Created 22
Table 4.0 Areas and Acreages of Disturbance 30
Table 5.1 Estimated Growth Media Volumes 38
Table 5.2 Seed Mix 39
Table 6.0 Predicted Pit Lake Quality at Full Recovery 59
Table 6.1 List of Fort Knox Buildings at Completion of Mining 66
Table 7.0 Summary of Closure Monitoring 70
Table 7.1 Summary of Monthly and Quarterly Analyte List 73
Table 7.2 Summary of Monitoring Requirements for Heap Leach 74
Table 7.3 Analytical Profile II—Groundwater Inorganic Parameters 75
Table 9.0 Reclamation & Closure Cost Estimate 77

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Fort Knox Reclamation & Closure Plan June 19, 2006

APPENDICES

APPENDIX A
Agreement for Funding Post-Reclamation Obligations

APPENDIX B
Surface and Mineral Land Descriptions and Claims Map

APPENDIX C
National Park Service, U.S. Department of the Interior, Fire Monitoring Handbook Point-
Intercept Method

APPENDIX D
Gil Causeway Reclamation Plan

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