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IV. Topsoil <br />Soil resource information is provided in Tab 9, Volume 5 of the permit application. <br />Information on topsoil handling, maintenance and testing is contained in Tab 21, <br />Volume 13. The PR-1 submittal extensively reorganized the soils sections of the <br />application and updated the soil baseline information to reflect 1990 survey of portions <br />of the north mine area which had not previously been surveyed. Baseline data had been <br />collected for the South Extension Area covered in PR-2, and in 1997 SCC conducted a <br />topsoil depth verification survey to corm the topsoil resource information collected <br />previously. This information is also included in Tab 9. The referenced permit sections <br />were further amended to address the expanded disturbance area associated with PR-3. <br />In PR-5, the Soil Survey Map (Exhibit 9-3) was updated to reflect disturbance <br />boundary modifications in the southern Wolf Creek/Sage Creek block in the south <br />extension area. Cessation of mining operations earlier than originally anticipated <br />resulted in a reduced area of disturbance in the deep "70D° soil map unit. <br />Associated updates were made to the Soil Replacement Map (Exhibit 21-1) and <br />topsoil balance narrative and tables in Tab 21. <br />The permit area is occupied by three soil orders; Mollisols, Entisols, and Aridisols. <br />The presence of these three orders is characteristic of the soils found in steep, semi-arid <br />regions of Northwestern Colorado. These orders represent soils that grade from <br />recently developed soils with minimum horizon development to more developed soils <br />with well developed diagnostic horizons. Specific soil types within these orders occur <br />on predominantly three types of parent material-land form combinations, namely: 1) <br />upper side slopes, ridges, and swales of sandstone residuum; 2) toe slopes, side slopes, <br />rounded ridge tops of shale residuum and colluvium; and 3) toe slopes, side slopes, <br />ridges, and escarpments of sandstone and shale. Among the 22 soil types occurring <br />within the permit area, major topsoil salvage limitations include clay textures, high <br />coarse fragment content, steep slopes, shallow bedrock, salinity, and alkalinity. <br />Seneca Coai Company strips topsoil in single lifts once the woody vegetation which <br />would interfere with handling of the topsoil has been removed, pursuant to 4.06.2(1). <br />As an optional approach, SCC has obtained approval [o use a roto-clear machine that <br />reduces large woody vegetation to chips, so that the vegetative material can be <br />incorporated with the topsoil during salvage operations. This technique has been <br />successfully employed at other surface mines in the region, and was used in the aspen <br />habitat within the Wolf Creek/Sage Creek mining block in 2004. Operator <br />reported that steep slope conditions presented difficulties for roto-clear operations. <br />Topsoil will be redistributed immediately on regraded areas when possible or stockpiled <br />in designated storage areas pursuant to 4.06.1(2). The amount to be stockpiled depends <br />on pit advance, season of the year, and reclamation activities taking place at the time of <br />salvage. Stockpiled topsoil is placed in stable areas and protected from wind and water <br />erosion by planting of aquick-growing vegetative cover. Single lift stripping mixes <br />Seneca II-W Findings Document 49 June 12, 2IXK <br />Permit Renewal No. 5 <br />