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swales post-mine. Surface drainage in the Phase I and Phase II bond release areas occurs <br />as sheet flow. There are no rills or gullies on these areas to indicate otherwise. Surface <br />water drainage flows in a northerly direction as it did in the pre-mine landscape. There are <br />two exceptions which serve the wildlife needs of the post-mining land use, the dugout <br />pond, and the cottonwood copse at the northeast edge of the 1985 reclaimed area. These <br />areas have been identified as providing valuable wildlife habitat in the area, and will both <br />remain to serve this function. Both CDMG and the Colorado Division of Wildlife have <br />approved the retention of these areas. <br />CDMG requested additional explanation of the Control Practice factor and slope lengths <br />used in the Phase II sedimentation analysis. <br />There was no interpolation involved in the selection of a value of unity (one) for the <br />Control Practice factor. This is the value suggested for use by CDMG in several prior <br />bond release cases where the USLE was used for sedimentation analysis. Slope lengths <br />were selected based on average slope lengths identified from pre-mining topographic maps <br />immediately south of the mine and the post-mining backfilled slopes within the 1985, 1986 <br />and 1987 reclaimed areas. <br />CEC trusts that the information provided in this response letter will be adequate to allow <br />for the final review and approval of Bond Release Application No. 1. Please contact me <br />if there are questions. <br />Sincer~, <br />Donald W. MacDonald `~ <br />Manager, Energy Services <br />enclosures <br />pc: Michael and Edith Savage <br />Savage & Savage <br />Gary Lake <br />Terranext <br />