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<br />The approved post-mining land use is rangeland in accordance with 2.05.5. The approved <br />seedmix and reclamation standazds are appropriate to support the post-mining land use. <br />QBSERVATIONS AND FINDINGS <br />Redistribution of topsoil occurred on the test pit area from July to November of 1989. Topsoil <br />was replaced on the remainder of the disturbed area during January and February 1992. Prior <br />to topsoiling, subsoil was reapplied at a thickness approximately equal to that originally removed, <br />33 inches. Topsoil was redistributed at a depth of 15 inches over the subsoil. These depths are <br />in agreement wiW soil replacement thickness required by We approved permit. The Division <br />verified the depths during a Mazch 1993 inspection. Six holes were sampled throughout the <br />reclaimed area. Four of the holes revealed that 24 to 32 inches of topsoil had been redistributed <br />over subsoil. One hole, located near the former location of subsoil stockpile No. 3, indicated <br />no topsoil present, as there was no change in texture down to a depth exceeding 36 inches. <br />Another hole, located near the former location of the north interceptor ditch, indicated a topsoil <br />thickness of 4 inches. This 4 inches of sandy topsoil was underlain by 8 inches of "coaley" <br />material, followed by 11 inches of subsoil. Kaiser Ventures sampled the topsoil replacement <br />depths on March 18, 1993. Table 2, included in the bond release application, tabulates the <br />results of this sampling. Data from twenty-five holes was presented, with a mean topsoil <br />replacement thickness of 14.3 inches and a standard deviation of 2.03. Ninety (90) percent of <br />the topsoil replacement standard of 15 inches equals 13.5 inches. Kaiser's sampling results <br />indicate that the topsoil replacement thickness average of 14.3 inches slightly exceeds the 13.5 <br />inches required and is approximately ninety-five (95) percent of the standard. <br />The approved permit requires re-establishing vegetative cover on the disturbed area at a <br />minimum of 90% of the vegetative cover present on the reference area. This commitment is <br />in agreement with Rule 4.15.8(3)(a), with the additional provision of achieving a 90% statistical <br />confidence interval. <br />Seeding was accomplished by drill seeding. Due to limited establishment of warm season <br />grasses, limited inter-seeding of the reclaimed area was conducted in 1993. The sediment <br />control system, diversion and collection ditches and sediment pond, were reclaimed and seeded <br />in February 1992. As allowed by Rule 3.03.1(5), the reclaimed sediment control facilities are <br />not subject to the same standazds as the rest of the disturbed area. The topsoil stockpile <br />footprint area mentioned in the Division's July 1996 inspection report was re-seeded during the <br />sediment control reclamation, hence this area would also fall under Rule 3.03.1(5). <br />The post-mining land-use of the reclamation is rangeland. Only the grassland community was <br />disturbed by the mining operation. Reclaimed areas were compared to the grassland reference <br />area. The pit and office area were reclaimed and seeded in November 1989. Vegetation <br />sampling occurred July 22, 1996. A representative from the Division was present during the <br />sampling. Vegetative cover was sampled using aCover-Point Projection Device, projecting an <br />ocular sight vertically downward and determining fast-hit data. Ocular hits on live vegetation <br />