2007-11-07_HYDROLOGY - M1977300

• Permit No: M1977300
• IBM Index Class Name: HYDROLOGY
• Doc Date: 11/7/2007
• Doc Name: Hydrologic evaluation of mine closure & reclamation
• From: Whetstone Associates
• To: Cotter Corpoartion
• Media Type: D
• Archive: No

Schwartzwalder Mine -Hydrologic Study of Mine Closure and Reclamation ni
145
9.4 Mine Water Chemistry .......................................................................................................
9.4.1 Geochemical Modeling Approach ........................................................................145
9.4.1.1 Mass Balance Mixing Model ...................................................................146
9.4.1.2 Evaluation of Precipitation and Dissolution Reactions Controlling Mine
ry ......................................................................................
Water Chemist 148
10. MINE CLOSURE AND RECLAMATION .................................................. ........................................151
10.1 Mine Reclamation Plan .............................................................. ........................................151
10.2 Closure Activities Performed to Date ........................................ ........................................151
10.2.1 Mine Reclamation ......................................................... ........................................151
152
10.2.2 Technologies Research ................................................. ........................................
10.3 Closure and Mitigation Strategies .............................................. ........................................153
10.3.1 Waste Rock Piles .......................................................... ........................................153
154
10.3.2 Alluvium and Fill .......................................................... ........................................
154
10.3.3 Underground Mine ....................................................... .........................................
...............155
11. CONCLUSIONS .......................................................................................... ..........................
................157
12. REFERENCES ............................................................................................. .........................
LIST OF APPENDICES
Appendix A Ralston Creek Flow Data
Appendix B Packer Test Methods and Results
Appendix C Monitoring Well Logs
Appendix D Pumping Test Methods and Results
Appendix E Mine Pumping Data
Appendix F Water Quality Data Base
Appendix G Sump Shut-Down Test Data
Appendix H Geochemical Model
LIST OF TABLES
Table 1. Monthly Climate Summary at Ralston Reservoir .............................................................................4
Table 2. Monthly Precipitation at Ralston Reservoir ......................................................................................5
Table 3. Elevations of Upper Levels at the Schwartzwalder Mine ................................................................18
Table 4. Flow Rates in Ralston Creek vs. Monthly Mean Precipitation at Ralston Reservoir ............•••••;::.13
Table 5. Stream Gaging Stations on Ralston Creek ............................................................................•••••• 15
Table 6. Stream Gaging Results for Ralston Creek Near Schwartzwalder Mine ................................••••••"' 16
Table 7. Seasonal Distribution of Average Flows in Ralston Creek .....................................................•••••"• 17
Table 8. Water Levels and Well Data for Bedrock Monitoring Wells MW 10 and MW 11 .........................
Table 9. Calculation of Vertical Gradients in Shallow Bedrock ...................................................................18
Table 10. Summary of Packer Permeability Test Results .............................................................................20
Whetstone Associates
4109B.071116