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to be disturbed on steep, southfacing slopes. The very thick Silas loam soil developed from alluvium <br /> within narrow bands along the larger ephemeral drainages. <br /> The predominant hill-slope soils have relatively thick, loamy textured mollic epipedons, well suited <br /> for reclamation use. Salvageable thickness of these soils averages from 12 inches to 30 inches. <br /> Subsoils in these units are somewhat marginal, due to heavier texture or excessive cobbles. The Silas <br /> loam soil along the drainage valley bottoms is generally suitable for salvage to depths of five feet or <br /> more. <br /> B. Topsoil Salvage Operations <br /> Information on topsoil salvage methods is found in Sections 2.04.9, 2.05.2 and 4.06 (Volume 1 for <br /> the East Pit, West Pit, Section 16 Pit, Facilities Area and Gossard Loadout; Volume 12 for South <br /> Taylor Pit; Volume 15 for Collom Pit) of the PAP. In general, the topsoil handling plan calls for <br /> removal of all of the A and some or all of the B horizon materials, depending on soil type. Average <br /> estimated soil salvage thicknesses map units (based on component series relative acreage) is <br /> presented in Tables 2.04.9-6 and 6A in the PAP. Projected salvage volume calculations for defined <br /> topsoil stripping blocks area are presented in Table 2.04.9-7 in the PAP. Specific areas where topsoil <br /> will not be salvaged are described in Section 4.06 of the PAP. <br /> Topsoil is removed during the late spring to fall, ahead of pit advancement. Vegetation, with the <br /> exception of large trees, will be removed and redistributed with the topsoil. Topsoil will be removed <br /> to topsoil stockpiles or, where possible, applied directly to regraded spoil. Within the South Taylor <br /> Pit and Collom Pit areas, most topsoil will be placed in stockpiles, as the nature of the operation will <br /> generally not allow for direct replacement. <br /> Topsoil stockpiles are shown on Maps 22, 28, 28A, 28B, and 28C of the PAP. Additional stockpiles <br /> located at the Gossard Loadout are located in the northern portion of the permit area and are shown <br /> on Map 25G of the PAP. All soils stockpiles will be protected from erosion and will not be moved <br /> without Division approval. <br /> In 1981 Colowyo committed to include information in its annual reclamation reports to verify that <br /> enough topsoil was being salvaged to replace a sufficient amount of soil on regraded areas. This <br /> information was reported until 1986. The Division suspended this monitoring requirement in 1987, <br /> as the data indicated that sufficient topsoil would be available to meet reclamation needs throughout <br /> the life of the mine. The Annual Topsoil Balance inventory and reporting requirement was <br /> reinitiated in association with TR-62 approved on May 29, 2006, and reporting resumed with <br /> submittal of the 2005 Annual Reclamation Report. The resumption of the annual reporting <br /> requirement was largely due to the fact that Colowyo became aware, based on a soil balance <br /> assessment in 2005, that there was insufficient topsoil in stockpiles to meet the 18-inch average <br /> replacement thickness requirement for disturbed areas that had not yet been topsoiled. <br /> An overall life of mine topsoil balance for the Colowyo Mine can be found in the 2017 Annual <br /> Reclamation Report. <br /> 40 <br /> Permit Revision No.5(PR-05),G 1981-019 <br />