Laserfiche WebLink
2.0 BACKGROUND INFORMATION/STATEMENT OF PROBLEM <br /> As part of the mine closure plan for the Sunnyside Mine, Sunnyside Gold Corporation <br /> (SGC) proposes to install underground bulkheads in the American Tunnel, Terry <br /> Tunnel, and Brenneman Vein. The bulkheads are designed to contain mine drainage, <br /> fill the lower mine workings with water, and allow ground water to return to an <br /> approximation of pre-mining hydrologic conditions. Detailed analyses of the <br /> hydrologic and hydrogeochemical impacts of the proposed bulkheads are discussed <br /> in Evaluation of Hydraulic and Hydrochemical Aspects of Proposed Bulkheads, <br /> Sunnyside Mine, San Juan County, Colorado dated March 12, 1993 by Simon Hydro- <br /> Search. For the purposes of this work plan a brief review of the conclusions is <br /> presented below. <br /> Currently, ground-water levels have been greatly lowered in the immediate vicinity of <br /> the Sunnyside workings as a result of mine dewatering. Ground water is drained from <br /> the workings through the American Tunnel. When the proposed bulkheads are <br /> installed, ground water in the mine workings is expected to return to an estimated pre- <br /> mining (equilibrium) elevation of approximately 11,500 feet msl. The ground-water <br /> gradient is anticipated to be generally toward the southwest (Figure 1 ). It is estimated <br /> that resaturation of the dewatered bedrock to pre-mining conditions will be <br /> substantially attained (86 percent) within ten years of bulkhead installation. <br /> sunny\wp\traci;2251\Workp1an 693 2 <br /> N0 simo 1 HYDRD-SEARCH <br />