Laserfiche WebLink
The parameters which most limited the suitability of these topsoil materials for their reclamation <br />potential was the coarse fragment content and the calcium carbonate equivalent. According to the <br />NRCS data presented in Table 2.04.9-5, NRCS Chemical Properties of the Soils, the soils <br />materials in the B horizon of the Pinon soils, at depths of greater than 6 inches, the Progresso <br />soils at depths of greater than 24 inches, and the Orthents soils at depths of greater than one inch <br />were classified as being classified as being of "poor" quality. Increased coarse fragment content <br />was always found in association with increased calcium carbonate equivalent. <br />The single most limiting parameter of these soils materials was determined to be their coarse <br />fragment content. According to directions provided by the DRMS, coarse fragment contents in <br />excess of 20 percent are "unsuitable" for use as a single lift material, during the topsoiling <br />removal and respreading. According to the data presented in Table 2.04.9-6, Chemical and <br />Physical Properties of New Horizon North Mine Soils, the Progresso soils often have coarse <br />fragment contents in excess of 20 percent. According to the NRCS Soils Survey Manual, a <br />sample of nearly 300 pounds is typically needed for accurate sieve analysis of coarse fragment <br />content. Logistically, it is impossible to collect such samples, therefore the coarse fragment <br />contents reported in the soils pedon descriptions found in Appendix 2.04.9-1, Soils Pedon <br />Descriptions are the most useful information available. Using these data all of the soils materials <br />were evaluated and classified with respect to the depth of salvageable topsoil. This information is <br />summarized on Map 2.04.9-3, New Horizon North Mine Topsoil Salvage Map, where the depths <br />and volumes of topsoil suitable for salvage are presented. <br />PRESENT AND POTENTIAL PRODUCTIVITY OF THE SOILS <br />The present and potential productivity of these soils as reported by the NRCS in the Soil Survey <br />of San Miguel Area, Colorado - Parts of Dolores, Montrose and San Miguel Counties is found <br />in permit section 2.04.3, Site Description and Land Use Information. The results of the <br />vegetation monitoring completed in connection with this permitting effort are presented in permit <br />Section 2.04.10, Vegetation Information. <br />Section 2.04.9 Page 31 Sept. 2015 (TR -11) <br />