2008-04-15_REVISION - M1980244 ‎(325)‎

• Permit No: M1980244
• IBM Index Class Name: REVISION
• Doc Date: 4/15/2008
• Doc Name: VOL II Appendix 2, Hydrologic Evaluation Report
• From: CC & V
• To: DRMS
• Type & Sequence: AM9
• Media Type: D
• Archive: No

•
CONTENTS

1.0
INTRODUCTION Page
1
1.1 Mine Life Extension activities summary 2
2.0 SITE DESCRIPTION 5
2.1 Site location and topography 5
2.3 Geological summary 8
3.0 MAIN PROJECT AREA HYDROLOGIC CONDITIONS g
3.1 Main project area general hydrology g
3.2 Main project area general hydrogeology g
3.3 Hydrologic monitoring program 10
3.4 Cripple Creek ~ 10
3.5 Arequa Gulch 12
3.8 Squaw Gulch
3.9 Vindicator Valley 16
17
3.10 Gold Run 18
4.0 GRASSY VALLEY HYDROLOGIC CONDITIONS 21
4.1 Grassy Valley description and background 21
4.2 2007 Field investigation activities 22
4.2.1 Investigation scope and objectives 22
4.2.2 Drilling and monitoring well and piezometer installation 22
4.3 Grassy Valley hydrologic and hydrogeologic conditions 23
4.4 Grassy Valley water balance modeling 28
4.4.1 Objectives 29
4.4.2 Conceptual model -current conditions 29
4.4.3 Conceptual model -mining conditions 29
4.4.4 Conceptual model -post-mining conditions 30
4.4.5 Input data 31
4.4.5 Calculations 34
4.4.6 Calibration to current conditions 36
4.4.7 Predictions for mining conditions 37
4.4.8 Predictions for post-mining conditions S7
4.4.9 Sensitivity Analysis 38
4.4.10 Water balance summary and conclusions 41
4.5 ECOSA design recommendations 42
5.0 SUMMARY AND CONCLUSIONS 45
5.1 Main project area 45
5.2 Grassy Valley area 46
REFERENCES 51
2736
Cripple Creek & Victor Mining Company
Water Management Consultants