2011-06-06_REVISION - M1981185 (49)

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May Day Idaho Mine Complex 112 (d) Permit Application (b) Measures to Prevent Wildlife Contacting Designated Chemicals All designated chemicals will be stored in locked facilities that cannot be accessed by Wildlife. 6.4.20(19) Disposal of Tailings in Mine Workings Wildcat Mining Corporation will comply with Rule 3.1.7 of the Reclamation Performance Standards for the protection of groundwater. Based on data provided within this Environmental Protection Plan, the following groundwater conceptual model has been developed for the protection of groundwater relative to the disposal of tailings in underground workings: • The geology consists of southward-dipping fractured sedimentary rocks cut by a series of east-west faults; • Limited amount of water enters from the surface via the fracture system (Exhibit G) that is not connected to the May Day No. 1 dry stacked tailings disposal site; • Based on observations in the underground workings, while water moves through the fracture system, the fractures and water are not pervasive • Sandstone units in the permit area are cemented and impermeable (Dr. Gonzales, Personal Communication, May, 2011); until r_.._' ing the Entfad.. Sandstone vdiieh a ~ to be the sattifat a zone, however-, fe&ely used to supper-t demestie or- ag6eultufal uses; • Faulting has offset the Entrada Sandstone creating a series of distinct unsaturated layers within the permit boundary: South of the fault zone within the permit boundary, the unsaturated zone appears to be at approximately 8,300 feet AMSL; Within the fault zone, the saturated zone appears to be at approximately 8,700 feet AMSL. Additionally, the faulting has separated the Entrada Formation from the aquifers within the La Plata alluvium, the Morrison Formation and the Mancos Shale; and The Entrada Sandstone is not considered a significant aquifer in Colorado. The conceptual model will be refined following further investigation. However, based on the available information, the following activities will be undertaken for the protection of groundwater: • A monitoring point will be established at the sump below the dry stacked tailings disposal site; • The point of compliance will a well located at the May Day No 2 bench below the proposed level of tailings disposal; • Samples will be collected quarterly and reported annually unless excursions are identified In the event excursions are identified. DRMS will be notified within 30 days of discover • In addition to the anal es presented in Attachment T-6 potassium will be used at the point of compliance (3.1.7(6) as surrogate parameter to provide an indication of potassium amyl xanthate as a possible contaminant source. REVISED June 5, 2011 May Day Idaho Mine Complex 112(d) Permit Application September 21, 2010 19