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• LORENCITO CANYON MINE <br />SOILS TECHNICAL REPORT <br />.:::.::a::..::':..:::::::.:S.:Q':q.^:'n2:C:.aAYV::.y:.F:../'!`:::'::'x::Vr.:.'a4:x3:.:::>.:3.::C:S :.:::::::.:::C::.::. <br />SECTION 1 -INTRODUCTION <br />Soil resources investigations were carried out in order to address Rule 2.04.9 of the Regulations <br />of the Colorado Mined Land Reclamation Board (MLRB) for Coal Mining. This section of the <br />regulations requires that the applicant "provide adequate soils information for those portions of <br />the permit area to be disturbed by surface operations and facilities." The principal objective of <br />the soil resources investigation was to determine the quality and volume of soil available for <br />reclamation. For this study, soil is defined as loose, unconsolidated surface material including the <br />A horizon (surface layer or topsoil) and B horizon (subsurface layer) as well as portions of the C <br />horizon (subsoil) suitable for plant growth. <br />SECTION 2 -METHODOLOGY <br />This soils assessment characterizes existing soil resources, soil erosion potential, and suitability <br />of the soils for reclamation material. Following review of existing data, an Order 2 soil survey <br />has been conducted within the proposed area of disturbance to gather quantity and quality data for <br />soil in order to accomplish reclamation goals. <br />• The U.S. Natural Resource Conservation Service (NRCS) office in Trinidad has conducted soils <br />mapping throughout the Lorencito Canyon Mine area as part of its effort to eventually publish a <br />soil survey of Las Animas County. NRCS mapping has been placed on 1:28,800 scale black and <br />white aerial photographs. A description for each mapping unit and soil series has been prepared <br />by NRCS. Mapping unit and series descriptions for soils within the proposed area of disturbance <br />are found in Appendix S-1. <br />Prior to initiation of field work, the aerial photo soils maps were compared with the facilities map <br />for the proposed mine. Topographic maps and natural color aerial photos of the mine area were <br />also examined. Based on proposed mine facilities locations, NRCS mapping, access road <br />locations, topography, vegetation types, and geomorphological features, preliminary soil sampling <br />locations were chosen. <br />The density and locations of soil pits was chosen to enable mapping soils at a minimum mapping <br />unit size delineation of two acres. Surface observations and inspection of manually excavated soil <br />pits or profiles were made to verify changes in soil types. A total of 24 locations were examined. <br />Of these, 17 pits were excavated by backhoe and 7 were excavated by hand using existing road <br />cuts and washouts in stream banks. <br />To describe a typical profile, pits or profiles were excavated by backhoe or by hand to 60 inches <br />or bedrock (whichever came first). The mapping unit descriptions are consistent with the National <br />soils A75/December 9, 1996 <br />