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<br />A description of the methods used to seal the mine adits follows. <br />Adit U-1: Native rock was placed for a distance of at ]east 30 feet into the mine and <br />up to the existing steel doors. The native rock extended from the mine <br />floor to the mine back. An additional 20 to 30 feet of native rock was <br />placed outside of the adit portal to deter unauthorized entrance, hide the <br />existence of a portal, and to closely approximate the pre-mining appearance <br />of the area. <br />Adit U-2: Native rock was placed for a distance of approximately 100 feet into the <br />mine and beyond the steel doors. The native rock extended from the mine <br />floor to the mine back for a horizontal distance of approximately 50 feet. <br />An additiona120 to 30 feet of native rock was placed outside of the adit <br />portal to deter unauthorized entrance, hide the existence of a portal, and to <br />closely approximate the pre-mining appearance of the area. <br />Adit L-1: The concrete and steel canopy over the portal was removed and placed <br />inside the mine adit. Native rock was placed for a distance of at ]east 30 <br />feet into the mine beyond the existing steel doors. The native rock <br />extended from the mine floor to the mine back. An additional 20 to 30 <br />feet of native rock was placed outside of the adit portal to deter <br />unauthorized entrance, hide the existence of a portal, and to closely <br />approximate the pre-mining appearance of the area. <br />Adit L-2: This adit had an existing concrete and steel casing with a steel door. A <br />rebar mat was placed in front of the steel door and a 2-foot thick layer of <br />3,000 pounds per square inch shotcrete was placed in front of the door. <br />After the concrete "wall" was placed, an additional 20 feet of native rock <br />was placed outside of the adit portal to deter unauthorized entrance, hide <br />the existence of a portal, and to closely approximate the pre-mining <br />appearance of the area. <br />2 <br />