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Colowyo Response - PR3 adequacy No. 2 10 May 6, 2011 <br />The Division acknowledges that a revised mine plan will be submitted by CCC during this PR3 <br />review. The Division may then have new adequacy review questions after reviewing the new mine <br />plan that have not been raised herein. <br />1. Please include elevation values on the pre-mining topography map, Map 1813. <br />The response was adequate. Elevations were added to contours on Map 18B and numerous <br />other maps. <br />2. Revised Mine plan Map 28B shows the proposed dimensions of the Little Collum X pit. This <br />map does not show haul roads into or out of Little Collum X pit, nor are any ramps depicted. <br />How will Colowyo access the pit? Please show haul roads and ramps into Little Collum X pit. <br />Haul roads are shown for Collum Lite Pit, but no ramps are shown. Please add placement of <br />Ramp locations Collum Lite Pit. <br />Colowyo's Response: <br />The Little Collom Xpit shown on Map 23B and other related drawings is very shallow. The <br />target X seam essentially outcrops in the area and there is very little overburden above the <br />coal. Along the pit perimeter, overburden depths increase to about 100 feet. Because the Little <br />Collom X pit floor is the base of the X seam coal, no ramps are required. <br />For the Collom Lite pit, the ramps into the pit are expected to change frequently during the <br />10 initial boxcut development. In pit ramps are of uniform slope of 10% or less. It is expected <br />that the Central Haul Road will be the primary haulage route during initial development, with <br />the East and West Haul Roads used more during the later stages of boxcut excavation and <br />during subsequent mining. Map 25D been modified to show the proposed ramp during initial <br />boxcut development. <br />Rule 2.05.3(3)(c) Mine Facilities-Roads and 4.03 Haul Roads and Access Roads <br />CCC's responses to adequacy Items 2.05.3(3)(c); 1, 2, 3, and 4 are currently being evaluated by the <br />Division. If additional questions remain regarding this section, the Division will send a third adequacy <br />letter under separate cover with regards to these items. <br />Colowyo's Response: <br />As of this submittal date, Colowyo has not received any comments regarding our response to <br />adequacy items 2.05.3(3)(c) 1, 2, 3, and 4. <br />Rule 2.05.3(4) Ponds, Impoundments, and Diversions <br />The application includes a plan to use an in-pit sump in combination with a large sediment pond <br />located below all mining within Collom Gulch. Geotechnical analyses for the pond were included <br />with the application. In general, the Division finds the plan adequate. However, based on recent <br />information regarding changes to the mine plan in the northern portion of the proposed permit area <br />due to Federal coal lease issues, runoff and sediment modeling will need to be rerun for the