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Jim Stover <br />February S, 2010 <br />Page 2 <br />Further review of additional available information, including the McClane and Munger Canyon permit <br />application documents, previous site inspections of the McClane and Munger Canyon Mines, applicable <br />rules and regulations, the August 1983 OSM publication "Alluvial Valley Floor Identification and Study <br />Guidelines", and review of pertinent satellite imagery ("Google Earth"), also support our informal <br />opinion that the footprint of the new proposed coal mine waste pile would not be located in an alluvial <br />valley floor. Please note that the preliminary information provided in the December 2009 ERO AVF <br />report has not been field verified and will need to be prior to a final determination and Findings by our <br />Division. Our informal opinion is discussed in the following points. <br />1) The area of land to be affected by the proposed coal mine waste pile is not located in an AVF but <br />is located adjacent to one. The immediate footprint of the proposed location for the new coal <br />mine waste pile would be located in or would overlay surficial geologic deposits including a <br />landslide, colluvium, fan deposits, and alluvium. According to the report prepared by ERO, <br />approximately 95% of the proposed waste pile site location is covered by deposits that resulted <br />from unconsolidated runoff or slope wash, talus, and landslide deposits. Therefore by Rule <br />2.06.8(3) (c) (ii) (C) the majority of the waste pile site is not an alluvial valley floor. <br />2) Approximately 5% of the area to be affected is composed of alluvium (Qal) exposed at the <br />surface. These areas are approximately 0.1 and 1.1 acres. By superimposing the footprint of the <br />proposed pile over Figure 2-Surficial Geology contained in the ERO report, it appears that these <br />two areas are the older alluvium of the East Salt Creek alluvium. These two areas are outside of <br />the incised channel and lie to the north and south of the landslide deposit (Qls). The larger 1.1 <br />acres of Qal is south of and adjacent to the landslide and would be covered by the new coal mine <br />waste pile. <br />These small areas of Qal are comprised of unconsolidated stream-laid deposits located on a <br />terrace of East Salt Creek and there is sufficient water available for flood irrigation. Therefore <br />these two small areas 0.1 and 1.1 acres meet the geomorphic criteria and water availability <br />criteria for an alluvial valley floor. <br />3) The small areas of Qal (0.1 and 1.1 acres, respectively) both meet the geomorphic criteria for an <br />alluvial valley floor, but they do not meet the regional practice criteria because they are too small. <br />Based on the ERO report, a review of existing irrigated areas along East Salt Creek indicates that <br />the smallest cultivated and irrigated parcel is 9.1 acres. The average of nine parcels is slightly <br />more than 30 acres. Based on this comparison with regional practices, the Division preliminarily <br />concurs that the limited alluvial areas within the coal mine waste pile location are too small to be <br />useful for agriculture and, therefore are not considered AVFs under Rule 2.06.8(c) (ii) (A). <br />4) For the reasons described above, it is the Division's informal opinion that the current positive <br />AVF determination for areas in the immediate footprint of the proposed coal mine waste pile can <br />likely be reversed. However, the area from the waste pile location west toward East Salt Creek is <br />an alluvial valley floor. We are concerned that access to and from the waste pile would impact a <br />larger area and those details have not been provided. There appears to be very little room to work <br />with as far as access to and from the pile and for any other support facilities necessary to operate <br />the pile. The location of the pile as proposed extends beyond the current permit boundary. <br />A Technical Revision (TR) to the PAP will be required to change the AVF designation within the area of <br />the new coal mine waste pile. During our review of the ERO report and other available information, we <br />have identified several items that need to be further addressed or clarified before the Division can render a <br />final determination and make an AVF Findings for this project. These items are briefly described below