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from the LDG. Wildcat committed to submitting a Technical Revision (TR) for review and approval by <br />DRMS once the additional information was available. <br />The proposed work to remove debris from the Little Deadwood Gulch and stabilize the highwall above <br />the Chief Portal will be broken into two phases as outlined below: <br />Phase 1— Removal of mine debris from Little Deadwood Gulch: <br />1. Installation of erosion and sediment control BMP's at the site. <br />2. Remove approximately 550 cubic yards of unauthorized fill from the LDG. Removed material will <br />be stockpiled and used for stabilization of the highwall above the Chief Portal. <br />3. Installation of a 24" culvert to allow the LDG to flow along its historical path. <br />4. Grade a bench area above the culvert that will provide vehicular access to the emergency <br />manway for the Chief Portal and install BMP's to prevent erosion while vegetation establishes. <br />5. Complete riparian and channel restoration activities required by the Restoration Plan that was <br />prepared for the EPA. This work in the Wetland Restoration Plan is beyond the requirements of <br />this TR and will be overseen by the EPA and /or the USACE. <br />Phase 2— Stabilize the highwall above the Chief Portal <br />1. Remove debris and loose dirt from the area immediately above the portal entrance. All loose dirt <br />removed will be stockpiled for use in reconstruction of the highwall. Trees, roots and trash <br />remove during this portion of the project will be disposed in a landfill. <br />2. Reconstruct the highwall above the Chief Portal to meet the recommendations stated in the <br />Rule 6.5 Geotechnical Stability Report — Chief Portal, dated March 16, 2013, prepared by <br />Wildcat Mining Corporation (the Geotechnical Stability Report), completed by J. Erich Rauber, <br />PE. <br />3. Extend the portal opening, through the use of a 66" pipe to the toe of the backfilled slope. <br />4. Stabilize the existing access road to May Day 3 and the portal access road. Stabilization <br />includes scarifying, moisture treating and compaction of the existing road alignment. <br />5. Installation of final BMP's to re- establish vegetation and stabilize the disturbed areas. <br />WORK PLAN <br />The following presents a corrective action work plan to remove debris from the LDG, install a culvert <br />within the channel, stabilize the highwall and access road immediately above the Chief Portal and repair <br />the emergency manway exit at the Chief Portal. Additional investigations were initiated to evaluate the <br />soil conditions in the immediate vicinity of the Chief Portal. Based on those recommendations, the <br />following design has been prepared to meet the conditions imposed by DRMS as part of the <br />conditionally approved 112d permit. This TR uses current geotechnical and topographic data to further <br />refine the design that was presented in the Original Work Plan and prepare the final construction <br />documents for the Little Deadwood Gulch and Chief Portal. <br />Chief Portal Work Plan Page 2 <br />P \Wmcduc \dwg \Eng \Final Drawings \DRMS TRs \b - Chief Portal TR \Chief Portal Work Plan -Revl .doc <br />