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Taylor Pit is, in fact, 20%, Colowyo needs to explain why there was the confusion regarding <br />the swell factor (being changed to 15%) in the first place. Either way, Colowyo has entered <br />an area that gives the Division pause with regards to TR-81 and a more detailed <br />explanation regarding the swell factor must be provided. Please provide the Division with <br />detailed explanation regarding both the initial decision to change the swell factor to 15% <br />and Colowyo's subsequent decision to not change the swell factor to 15%. Given the <br />Division's discussion regarding swell factors above and in the original text of question 2 <br />(contained in the Division's 11 March 2010 Preliminary Adequacy Letter), please also <br />explain what is meant by the statement "(a)t such time in the future when Colowyo deems it <br />prudent to change the permitted swell factor...". <br />Response: The change in swell factor requested in prior submittals of Technical Revision 81 (TR- <br />81) resulted from an error on the part of Colowyo's engineering staff. This was <br />noticed after the Division's preliminary review of TR-81 and was immediately changed <br />back to the correct, permitted swell factor. Colowyo apologizes for this error and the <br />confusion it has caused. The statement referring to the prudency for a future change <br />was meant to state that only when geologic conditions exist and scientific studies <br />support a change in swell factor would Colowyo request a change in the permitted <br />swell factor. <br />3. Response Partially Accepted. The revised Table 2.05.2-2 does contain the revised <br />coal and overburden volumes for the South Taylor Pit for the life-of-mine. The revised table <br />removes information regarding topsoil volumes and East and West Pit topsoil volumes. <br />Additionally, no information is provided for permanent and temporary overburden. Please <br />either add back the rows for topsoil volumes that were removed from Table 2.05.2-2 or <br />explain why these rows were removed. Please add information on yearly permanent and <br />temporary overburden volumes to Table 2.05.2-2. <br />Response: As discussed in our meeting at Colowyo, it was decided to delete this table and the <br />associated listing in the table of contents. No text reference to the table exists in <br />Volume 12, so no other deletions are necessary. <br />Rule 2.10 - Maps <br />4. Response Accepted. Colowyo has provided a new Map 45 with one east-west cross- <br />section as requested. <br />5. Map 19B - Postmining Topography - South Taylor Area <br />a. Response Accepted. Tick marks have been added. <br />b. Response Accepted. The revised post-mining topography (Map 19B) has <br />addressed this concern. <br />6. Map 23A - Mine Plan - South Taylor Area <br />a. Response Accepted. South Taylor cross-sections have been added as requested. <br />b. Response Accepted. The area in question is the box-cut area, therefore, additional <br />time is required to complete mining. <br />7. Map 20B - Premining & Postmining Cross Sections - South Taylor Area