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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, Volume <br />13. The PR -1 submittal extensively reorganized the soils sections of the application and <br />updated the soil baseline information to reflect 1990 survey of portions of the north mine <br />area which had not previously been surveyed. Baseline data had been collected for the <br />South Extension Area covered in PR -2, and in 1997 SCC conducted a topsoil depth <br />verification survey to confirm the topsoil resource information collected previously. This <br />information is also included in Tab 9. The referenced permit sections were further <br />amended to address the expanded disturbance area associated with PR -3. In PR -5, the <br />Soil Survey Map (Exhibit 9 -3) was updated to reflect disturbance boundary modifications <br />in the southern Wolf Creek/Sage Creek block in the south extension area. Cessation of <br />mining operations earlier than originally anticipated resulted in a reduced area of <br />disturbance in the deep "701)" soil map unit. Associated updates were made to the Soil <br />Replacement Map (Exhibit 21 -1) and topsoil balance narrative and tables in Tab 21. <br />The permit area is occupied by three soil orders; Mollisols, Entisols, and Aridisols. The <br />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 recently <br />developed soils with minimum horizon development to more developed soils with well <br />developed diagnostic horizons. Specific soil types within these orders occur on <br />predominantly three types of parent material -land form combinations, namely: 1) upper <br />side slopes, ridges, and swales of sandstone residuum; 2) toe slopes, side slopes, rounded <br />ridge tops of shale residuum and colluvium; and 3) toe slopes, side slopes, ridges, and <br />escarpments of sandstone and shale. Among the 22 soil types occurring within the permit <br />area, major topsoil salvage limitations include clay textures, high coarse fragment <br />content, steep slopes, shallow bedrock, salinity, and alkalinity. <br />Seneca Coal 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). As <br />an optional approach, SCC obtained approval to use a roto -clear machine that reduces <br />large woody vegetation to chips, so that the vegetative material could be incorporated <br />with the topsoil during salvage operations. This technique has been successfully <br />employed at other surface mines in the region, and was used in the aspen habitat within <br />the Wolf Creek/Sage Creek mining block in 2004. Topsoil was redistributed <br />immediately on regraded areas when possible or was stockpiled in designated storage <br />areas pursuant to 4.06.1(2). The amount stockpiled depended on pit advance, season of <br />the year, and reclamation activities taking place at the time of salvage. Stockpiled topsoil <br />was placed in stable areas and protected from wind and water erosion by planting of a <br />quick - growing vegetative cover. Single lift stripping mixes different soil horizons and <br />thereby dilutes heavy clay concentrations encountered in various subsoils. Although soil <br />survey information and soil handling plans contained in the PR -1 application were <br />Seneca II -W Findings Document 42 C- 1982 -057 <br />Permit Revision No. 6 January 6, 2012 <br />