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• <br />Over time, weed vegetation has built up on the pad area. These weeds will be sprayed and then the <br />topsoil will be stripped to a depth of 6 inches and stockpiled in a perimeter berm around the entire area. <br />This berm will be a minimum of 2 feet high with sideslopes of 2H:1 V. This berm will isolate the site <br />from all outside area runoff. The topsoil will be seeded with the mix described in the Reclamation Plan <br />within 3 months after construction. The runoff from the site itself will be collected in a sediment sump <br />which is large enough to contain the 100 year - 24 hour event from the 0.41 acre site. In addition to the <br />power drop, the site may also be used to store portable equipment, a water tank, and an air compressor. <br />The power drop to the Whirlwind Mine will be run through an existing 12-inch diameter drill hole <br />from the top of the mesa to a transformer located in the mine, approximately 540 feet below. This hole, <br />which is cased and grouted, was completed by Little Maverick Mining Company under approved NOI <br />M-2005-016. It is located southwest of the mine portal and is shown on Map C-1B. This permit area <br />will be 100 feet x 100 feet in size, which is identical to the ventilation shaft areas. The area will be <br />stripped of topsoil and bermed similar to the Packrat portal drop area described above. <br />• <br />Reclamation of the two cased holes and associated pad areas has been included in the reclamation cost <br />estimate (see Exhibit E). <br />18. Water Management <br />Surface drainage control is divided into the following three main categories: <br />1.Surface drainage from undisturbed areas uphill from both portal areas will be permanently diverted <br />around the mine area via constructed ditches and culverts. This water will be diverted directly to <br />nearby natural drainages. All such diversion ditches and culverts are designed for the NOAA year <br />round 100-year, 24-hour storm event of 2.9 inches. This is more conservative than the lower rainfall <br />presented in TR-55, which is more widely used in Colorado for determining peak flows. All ditches <br />have a maximum sideslope of 2H:1 V and 0.3 feet freeboard. Any ditch with a design flow greater than <br />5.0 feet per second is designated for arip-rap lining, which is also designed to withstand the peak flow <br />• from the 100-year 24-hour event. <br />Whirlwind Mine 07 (rev. April 08) D-28 <br />