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Schwartzwalder Mine -Hydrologic Study of Mine Closure and Reclamation ~ <br />TABLE OF CONTENTS <br />1. INTRODUCTION .....................................................................................................................................1 <br />2. SITE DESCRIPTION ................................................................................................................................1 <br />2.1 Location .................................................................................................................................1 <br />2.2 Terrain ....................................................................................................................................4 <br />2.3 Climate ...................................................................................................................................4 <br />2.4 Economic Geology ................................................................................................................5 <br />2.5 Mine History ..........................................................................................................................8 <br />2.6 Mine Layout ...........................................................................................................................8 <br />3. SURFACE WATER FLOW ......................................................................................................................9 <br />3.1 Flow in Ralston Creek at Ralston Reservoir ..........................................................................9 <br />3.2 Flow in Ralston Creek at the Schwartzwalder Mine ............................................................12 <br />4. GROUNDWATER ..................................................................................................................................16 <br /> ........................16 <br />4.1 Groun <br />1 <br />4 <br />1 dwater in Bedrock ....................................................................... <br />Depth to Water and Groundwater Flow ................................... ....... <br />...............................17 <br />. <br />. <br />4.1.2 Bedrock Permeability Tests ..................................................... ...............................19 <br />4.2 Groun dwater in Alluvium ..................................................................... ...............................20 <br />1 <br />4 <br />2 Thickness and Extent of the Alluvium ..................................... ...............................21 <br />. <br />. <br />4.2.2 Alluvial Permeability Tests ..................................................... ...............................21 <br />23 <br />4.2.3 Sump Pumping ........................................................................ ................................ <br /> .................. 27 <br />4.3 Seeps .................................................................................................... .............. <br />5. MINE HYDROLOGY ............................................................................................................................27 <br /> .........................27 <br />5.1 Concep tual Hydrologic Model ........................................................... ......... <br /> ...........29 <br />5.2 Mine Inflow ....................................................................................... ....................... <br />5.2.1 Pumping Records .................................................................. ..................................29 <br />32 <br />5.2.2 Sources of Inflow .................................................................. .................................. <br />34 <br />5.2.3 Observed Rate of Mine Flooding .......................................... ...........................••••"'39 <br />5.2.4 <br />................ <br />Projected Final Water Level .•••••••••••••••••••••••••••••••• ••••••••••••••••••••""""""" <br />5.3 Evaluation of the Hydraulic Connection Between Ralston Creek and the Mine .................41 <br />1 <br />5 <br />3 Evidence from Stream Flow Data ......................................... ..................................41 <br />. <br />. <br />5.3.2 Evidence from Mine Pumping Rates .................................... ..................................41 <br />41 <br />3 <br />3 <br />5 Stable Isotopic Analysis of Mine Water and Ralston Creek ................................... <br />. <br />. <br />5.3.4 Tritium Dating of Mine Water ............................................. ...................................43 <br />............43 <br />5.3.5 Summary .............................................................................. ....................... <br />Whetstone Associates • <br />4109B.071116 <br />