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Bob Oswald <br />Re: Topaz Mine, Permit M-1980-055 HR <br />Response to August 12, 2003 Adequacy Review, Technical Revision Tr-O1 <br />Page 2 of 3 <br />concrete. The shop floor slab is reinforced with wire mesh, and occasionally minor <br />amounts of trash steel were placed in the pour for additional strength. <br />The shop building is 35' x 20'. <br />(4) If known at this time, please provide the adit dimensions, the type of equipment to be <br />used, and the slope gradient of the exterior surface. <br />Response: The entrance to the portal is a 14' diameter circular steel archway which <br />provides ground support at the entrance, a gate attachment, etc. The decline is <br />approximately 10' x 10' in section. The steel archway will removed prior to plugging the <br />portal. <br />Filling and reclamation of the portal will be conducted with a small capacity front-end <br />loader (likely in the 3 cu. yd. range). In addition, a small track mounted dozer, or <br />equivalent, will be used to push fill material up in the portal to ensure that it remains <br />stable. <br />As with all disturbed areas occurring on sloping ground, the final graded exterior surface <br />of the portal plug will not exceed 2:1 slope. <br />(S) Does the stated 2:1 gradient also pertain to other slopes created on the site (such as cut <br />faces above the benches, or slopes adjacent to the roads)? <br />Response: The general practice will be to reduce all "created slopes" to a gradient of not <br />more than 2:1. However, as a practical consideration there will be occasions when <br />reduction of slopes will not be performed if the required grading will create greater <br />disturbance and potentially cause site erosion. As stated, the normal practice will be to <br />reduce all slopes, but possible exceptions might include benches or road cuts that have <br />already revegetated or stabilized or which can only be graded by cutting new access, <br />provided however that the existing face is stable and not eroding. <br />(6) Please clarify what the road reclamation will consist of. <br />Response: Road closure 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 <br />bars will be placed at select locations to prevent buildup of runoff down the road surface; <br />the numbers of bars will be minimal to avoid additional disturbance. The road surface <br />will be scarified to relieve compaction and to provide a seed bed. Upon completion of <br />grading and scarifying, the disturbed areas will be seeded by broadcast seeding, followed <br />by light harrowing or dragging to embed seeds. <br />(7) Please clarify the volume of topsoil present, what portions of the site will be topsoiled, <br />and the depth is wi!! be spread <br />As reported in the Operator's correspondence of March 23, 2003, the topsoil stockpile <br />portrayed on the 1" = 100' TOPAZ MINE site map is estimated to be approximately 350 <br />yd'. If the topsoil is spread 4" thick, it will cover an area of less than one acre. <br />Therefore, the area to be "topsoiled" in final reclamation becomes a bit academic, but the <br />most beneficial location for the soil would be near the west entrance to the mine site to <br />stabilize this area as quickly as possible. <br />