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<br />Mr. Steve Wathen <br />Division of Minerals and Geology <br />Page 2 <br />its review and approval alternative construction <br />recommendations was specific only to the toe of the fill <br />if deemed necessary by analysis from CTL/Thompson. As <br />Mr. Pendleton notes in his comment #4, additional borings <br />or excavations to verify the subsurface geologic <br />conditions beneath the toe of the fill are no longer <br />warranted since the toe of the reconfigured fill <br />coincides with borings TH-2A and TH-3. Therefore, it has <br />not been necessary for the Division to review and approve <br />any changes in fill construction in the vicinity of the <br />toe area. <br />During the inspection of September 30, 1992 Colowyo <br />discussed at length with Division and OSMRE personnel the <br />modification to the drain alignment. Since only the <br />drain alignment was modified and all other construction <br />plan requirements would be met or exceeded and the change <br />did not involve the bedrock/toe issue we proposed no <br />modifications for the Division to review and approve. We <br />further discussed that it was our intention to provide an <br />as-built drawing at the time we submitted the required <br />subdrain completion and inspection report. Mr. Mike <br />Long, Division Director, was also on-site that same day <br />and was queried as to the appropriateness of our proposal <br />and concurred that the as-built certification would be <br />sufficient in this instance. <br />Nevertheless, we have included with today's submittal a <br />drawing that provides the detail of the realigned <br />subdrain. The subdrain was realigned for the following <br />two reasons. <br />A) It was evident in the field that after topsoil <br />was removed, the low point of the original <br />natural drainage was located further to the <br />west than anticipated in the original design. <br />To meet the requirements of Rule <br />4.09.2(2)(b)(i) it was necessary to realign <br />the subdrain to this new configuration. <br />B) The upper limit, or head, of this new natural <br />drainage intersected quite nicely with the <br />downdip point of the X seam coal outcropping <br />at the western limit of the fill. While we <br />have not experienced any groundwater buildup <br />in the pit backfill, this realigned subdrain <br />intersects with that point of the Section 16 <br />boxcut backfill that could, theoretically, <br />generate the most concentrated groundwater <br />flow from the reclaimed areas. In theory, if <br />any groundwater was produced from this part of <br />