2010-12-17_REVISION - C1981019 (142)

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Baseline Survey of Soil Resources - Collom Mining Area July, 2006 The Moffat County and Rio Blanco Areas were previously mapped by the NRCS to a level of detail commensurate to an Order III survey (USDA 2005a; 2005b). The databases and digital maps from these surveys were used to develop a conceptual model. These maps were used in combination with aerial photographs to identify likely changes in soil conditions within the Survey Area. The attendant survey reports were used to identify soil series present in the area to ensure that this survey correlates to the existing surveys as much as practicable. However, only the 43 series present as major components of the NRCS map units within five miles of the Survey Area were used. The locations of observation points were selected to be representative of a map unit or to help determine the composition of a map unit. These sites were identified through review of aerial photographs, topographic maps, and site inspection. A backhoe was used to excavate the majority of the observation points, with most exceptions being those points not readily accessible from existing roads and trails, or sites determined unsafe (e.g., steep slopes) for equipment operation. Sites not excavated with a backhoe were excavated manually using a shovel or hand auger. All profiles were described using methods and abbreviations identified in the Field Book for Sampling and Describing Soils (NRCS 2002), with modification as noted in this section. Complete or partial pedon descriptions were recorded on forms developed for this survey for each of the observed pedons. Complete pedon descriptions were recorded at the most representative pedons and all sites sampled for series representation. Partial pedon descriptions, consisting of an abbreviated list of soil characteristics, were completed for pedons exhibiting common characteristics or those manually excavated to a shallow depth. They were generally used to improve efficiency of data collection where conditions did not allow for complete description or where such a description was redundant. All sites excavated with a backhoe were described to a depth of 60 inches or to the bedrock contact, whichever occurred first. However, manual excavations and attendant excavations were only completed to the depth necessary to identify the soil series or family and depth of material suitable for salvage (generally the entire thickness of the solum / or to a depth of high coarse fragment content or lithic contact). l Sample Collection Samples were collected from 9S pedons determined in the field to be representative of soils in the area. These samples were collected entirely from within the Order II Survey Area. Selected soil samples were generally collected from pedons where the soil series or family was a dominant component of the map unit. Soil samples were collected from horizons greater than three inches thick. Horizons less than three inches thick were occasionally sampled along with the most similar adjacent horizon, unless the horizon was anomalous in nature. Horizons greater than 18 inches thick were collected from the lower portion of the soil horizon. One to eight samples were collected from each sampled pedon, with more than four samples collected from each site on average. A total of 426 samples were collected for laboratory analysis. Laboratory Analyses Soil samples were transported under chain-of-custody protocol to Intermountain Laboratories, Inc. in Sheridan, Wyoming for analysis. All parameters were analyzed using the methods specified by the Wyoming Department of Environmental Quality (WDEQ) Topsoil and Overburden Guidelines (Guideline I; WDEQ 2004). The parameters analyzed include the following: ? Texture (including the sample's coarse fragment content and percentage of sand, very fine sand, silt and clay) ? pH (acidity/alkalinity) ? Electrical Conductivity ? Sodium Adsorption Ratio (SAR) ? Saturation Percentage Tetra Tech, Inc. 2