2010-09-29_REVISION - M1981185 ‎(13)‎

• Permit No: M1981185
• IBM Index Class Name: REVISION
• Doc Date: 9/29/2010
• Doc Name: Conversion Application for a 112‎(d)‎ permit Part 3 Exhibit T-1 thru Exhibit T-4
• From: Wildcat Mining, Co
• To: DRMS
• Type & Sequence: CN1
• Email Name: WHE
• Media Type: D
• Archive: No

May Day Idaho Mine Complex 112 (d) Permit Application

Age Formation San Juan Basin
H dro eolo is Unit Hydrologic
Characteristics
Upper Cretaceous Mancos Shale Confining Layer Well fields as much as 10 m
Dakota Sandstone Dakota Aquifer Well yields as much as 10 m
Upper Jurassic Morrison: Formation Morrison Aquifer Well vields as mucli as 25?gpin
Junction Creek Sandstone
Wanakah Formation -
Entrada Sandstone - -
Not siuniticant in Colorado
?
Jurassic and Dolores Formation
Upper Triassic Nolcon"idered siZ,21111icanl in Colorado
Permian Cutler Formation Base of San Juan Basin
Rico Formation
Pennsylvanian Hermosa Formation
Ore-bearing veins are north-trending, mainly found within the Junction Creek Sandstone,
Wanakah Formation and Entrada Sandstone (Eckel, 1949). As can be seen from the
above table, the ore-bearing veins are below the reported aquifer (Morrison Formation).
There is little published information regarding groundwater conditions in the vicinity of
the mine site. A review of well permits within 2-miles of the mine entrance (Attachment
T-2) indicates that most wells are located either within the alluvial material of the La
Plata River, sandstone (presumed to be the Morrison Formation) north of the fault system
or the Mancos Shale south of the fault system. A summary of geological information
based on review of well permits is presented in Attachment T-2.
Discussions with Dr. David Gonzales, Fort Lewis College, who is familiar with the
underground workings within the permit area, suggests that the groundwater is contained
within fractured systems of the sedimentary host rocks within the permit area. This has
been determined based on observations of the presence of water within the workings.
Only one tunnel is believed to be flooded - Level 423 and 545 at approximately 8,300
feet AMSL (Dr. David Gonzalez, pers. comm.). This tunnel is located within the Entrada
Sandstone south of the May Day Fault, and in the absence of other data, this is considered
to be the level of the saturated zone in this portion of the permit area.
The only other report of water is within the Valley View Vein, between the Idaho and
May Day faults. Water is reported at 8,700 feet AMSL within the Entrada Formation
(Dr. David Gonzalez, pers. comm.). Water is discharging from the Idaho No. 1 adit at an
approximate elevation of 8,800 feet AMSL, also within the Entrada Sandstone. Given
the uncertainty of the data veracity, the more conservative elevation of 8,700 feet AMSL
will be used for water levels within the May Day-Idaho Fault System for planning
purposes.
A cross-section presented by the Colorado Geological Survey is prepared for the mine
area (Kirkham et. al., 2000) and is reproduced in Attachment T-3. Based on the
interpretation presented Kirkham et. al. (2000), the Entrada Formation is exposed in the
vicinity of the Idaho Operational Area.
May Day Idaho Mine Complex 112(d) Permit Application
September 21, 2010