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1 <br /> ' below the surface during the period between September <br /> and December. Since it is situated 30 to 65 feet higher <br /> than the elevation of the U. S. Bureau of Mines' test <br /> ' area, the ground water level under the Vhite Cloud and <br /> Vynona Mines, and the millsite and tailings impoundment <br /> area, is somewhat lower than 53 feet below the surface. <br /> ' A similar decline in the ground water level undoubtedly <br /> occurs beneath these areas during these same months. <br /> 2B. Following is a description of the tailing pond that <br /> ' currently exists in the permitted area and how it is to <br /> be maintained. <br /> ' 1. All sharp rocks, large stones, roots, vegetation, <br /> and other foreign material were removed from the <br /> interior of the tailings impoundment area. <br /> ' 2. All of the remaining surface irregularities were <br /> smoothed out and a layer of compacted decomposed <br /> granite was placed on the bottom and sides of the <br /> ' tailings retention structure. <br /> 3. An anchor trench 24 inches wide by 36 inches deep <br /> ' was dug with a backhoe around the inner perimeter of the <br /> tailings dam to hold the edge of the geomembrane line. <br /> This trench was dug a minimum of at least 1 foot from <br /> ' the interior slope of the tailings impounding area. <br /> 4. A polyethylene plastic geomembrane liner with <br /> thickness of 30 mils was placed over the prepared ground <br /> ' surface in a manner that assured a minimum of handling <br /> so that the interior of the tailings pond was not <br /> disturbed. <br /> ' 5. The geomembrane liner was closely fitted and sealed <br /> around the only outlet in the liner. There are no other <br /> ' projections through the tailings pond line. <br /> 6. The portions of the geomembrane liner that were <br /> damaged during installation were removed and repaired <br /> ' with additional pieces of 30 mil polyethylene lining <br /> material . <br /> ' 7. The separate panels of the geomembrane liner were <br /> sealed together with a heat fusion method that employed <br /> a digital temperature controlled hot shoe plastic <br /> welder. <br /> 8. The lap joints of the polyethylene panels were <br /> formed by overlapping the edges of the panels a minimum <br /> distance of 12 inches. <br /> 9. The contact surfaces of the lap ,points were wiped <br /> ' clean so that all dirt, dust, and other foreign <br />