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a time as the Section 21 Pond is constructed. As such, the ditch has been <br />reconfigured and moved from approximately Station 45+00 to its end-point. <br />This moves the ditch approximately 250 feet to the southeast of its current <br />location. This move increases the area of the contributing watershed and <br />catches the additional disturbed area runoff and diverts it to the Section 16 <br />Pond. The Division has some concerns with the design of the Section 16 Pond <br />ditch extension. Specifically, there are two 90° bends in the reconfigured <br />ditch, one changing the direction of flow to the southeast at approximately <br />Station 45+00 and the other changing the direction of flow to the southwest at <br />approximately Station 48+00. These extreme angles are generally areas that <br />can cause stability problems for ditches. Please describe for the Division <br />and include in the text for Exhibit 7, Item 140, how Colowyo plans to <br />address the possible stability problems at these two 90° bends in the ditch <br />extension. <br />5. When Colowyo completes construction on the new Section 16 Pond extension <br />ditch, there will be a portion of the "old" Section 16 Pond (first) extension <br />ditch that will remain to the northwest of the new extension. The portion that <br />will remain is from approximately Station 45+00 to Station 55+00 on the <br />currently approved Figures 1 and 2. If the "old" portion of the Section 16 <br />Pond ditch is not reclaimed it could cause major maintenance problems with <br />the remaining portion of the ditch north of Station 45+00. The Division <br />believes that this "old" portion of the ditch should be reclaimed concurrent <br />with the new ditch being constructed. Please provide the Division with <br />details regarding Colowyo's plans for the "old" portion of the Section 16 <br />Pond ditch that will not be needed after the construction of the second <br />extension is complete. <br />This concludes the preliminary adequacy review for the Colowyo Mine's Technical <br />Revision 71. The proposed decision date for this revision is 6 June 2008. In order to <br />meet this date, Colowyo's prompt responses to this adequacy review are requested. <br />Please contact me at (303) 866-4929 if you have any questions or comments. <br />Sincerely, <br />James R. Stark <br />Environmental Protection Specialist <br />cc: Sandy Brown <br />