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Bob Oswald <br />Re: Sunday Mine, Permit M-1977-285 <br />Request for Technical Revision <br />Page 5 of 6 <br />- A "boneyard" area exists to the west of the warehouse/wash bay. Various old pieces <br />of equipment and materials are located here, but there are no permanent structures. <br />- A truck scale is located in the center of the mine yard, neaz an ore dump and loadout <br />station. <br />- A small diameter vent pipe with a riser with a fan on it is located in the center of the <br />yard in the slope of an interior waste dump. Although this vent hole is most likely a <br />pre-Law feature, it will be closed as part of dump grading during final mine <br />reclamation. <br />Vent Hole S-2 is located at the south center edge of the mine yard, but it is included in the <br />Disturbed Area associated with the Roads and Vent Holes (Figure 2). <br />Yent Shafts: A total of eight vent shafts, including S-2 noted above, are included under <br />the Sunday Mine Permit. Construction details of each of these vent shafts are not available, but <br />for planning purposes and closure estimation, all eight vents can conservatively be assumed to be <br />seven foot diameter and 750 feet deep. <br />All vent shafts have a concrete collar approximately 16 feet in diameter and 30 inches thick <br />extending around the bored shaft. The opening of each vent shaft is a hole in the concrete <br />"donut" forming the collar. The approximate volume of concrete in each slab is 14 yd3. <br />Reclamation of vent holes will include removal of the fan and any surface hardware, followed by <br />backfilling the shaft with native waste rock obtained from local borrow areas and waste dumps <br />(no dumps from vent hole excavation exist on the surface at the vent sites as the shafts were <br />upreamed and the cuttings were collected in the mines). The shafts will be filled to within a few <br />feet of the surface (leaving adequate room to dispose of the broken collar) and observed For not <br />less than five days to ensure that no settling of the fill takes place, after which, the top of the hole <br />will be filled with native rock and soil. <br />Dump Grading: Outslopes of dumps will be graded to slopes of no steeper than 2 <br />Horizontal : 1 Vertical to provide suitable faces for reclamation and to blend reclaimed dumps <br />into existing site contours. The general practice will be to reduce all "created slopes" to a <br />gradient of not more than 2:1. However, as a practical consideration there will be occasions <br />when reduction of slopes will not be performed if the required grading will lead to greater <br />disturbance and potentially cause site erosion. As stated, the normal practice will be to reduce <br />all slopes, but possible exceptions might include benches or road cuts that have already <br />revegetated or stabilized or which can only be graded by cutting new access, provided however <br />that the existing face is stable and not eroding. <br />Access Roads.• Road closures and reclamation will consist of grading shoulders, cuts, and <br />ditches, if necessary, to reduce slopes to 2:1 or less. In conjunction with grading, water bars will <br />be placed at select locations to prevent buildup of runoff down the road surfaces; the number of <br />bars will be minimal to avoid additional disturbance. The road surfaces will be scarified to <br />relieve compaction and to provide a seed bed. Upon completion of grading and scarifying, the <br />disturbed aeeas will be seeded by broadcast seeding, followed by light harrowing or dragging to <br />embed seeds. <br />