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ditch. The field data showed that the elevation of the ditch, as constructed, matches that of the <br />design from Map 33. The ditch location was also compared with the permitted location shown <br />on Map 41 and the ditch was found to be constructed in the correct location. Finally, the ditch <br />construction was compared with the design requirements in Exhibit 7-14G. The approved <br />designs call for a ditch with a 10 foot bottom width, 3:1 side slopes, a depth of 1.7-1.8 feet and <br />riprap with a D5o ranging from 9-18 inches. The on-the-ground measurements showed that the <br />ditch had a bottom width of approximately 20 feet, side slopes that were approximately 3:1 and a <br />depth ranging from approximately 3-5 feet. The riprap in the bottom of the ditch conformed to <br />the required D50 sizing of 9-18 inches. In addition, the side slopes of the ditch were armored <br />with larger riprap. No problems were noted with side-cutting along the length of the ditch and <br />the ditch has reached equilibrium at this point. The Division is not proposing to release any <br />portion of the Gulch A Ditch with SL-04. <br />The Phase I area of the West Pit drains into the West Pit Fill Ditch and ultimately into the West <br />Pit Pond. The West Pit ditch is a riprapped channel that was stable. All of the runoff from the <br />West Pit Fill, including the Phase I Bond Release areas, flows from a series of contour ditches <br />into the West Pit Fill Ditch. The West Pit Fill Ditch is not in any of the West Pit reclamation <br />blocks requested for release and the Division is not proposing to release any portion of the West <br />Pit Fill Ditch with SL-04. <br />The Phase I area of the Section 16 Pit drains into the Section 16 Pond Ditch and the Section 16 <br />Fill Ditch and ultimately into the Section 16 Pond. The Section 16 Pond Ditch and the Section <br />16 Fill Ditch are riprapped channels and both were stable. Runoff from the area flows overland <br />into these ditches. The Section 16 Pond Ditch or the Section 16 Fill Ditch are not in any of the <br />Section 16 Pit reclamation blocks requested for release and the Division is not proposing to <br />release any portion of the Section 16 Pond Ditch or the Section 16 Fill Ditch with SL-04. <br />Topsoil Replacement <br />The required (average) topsoil replacement depth for all of the Phase II reclamation blocks is 18 <br />inches (Permit Volume 1, page 2.05-28). Colowyo includes an annual topsoil replacement <br />balance in Section 11 of their Annual Reclamation Report (in Exhibit 11-1). The average <br />replacement depth is calculated based on the acreage of the specific reclamation block and the <br />total volume of topsoil hauled and spread on that reclamation block. A review of the data from <br />the Colowyo Annual Reclamation Report shows that Colowyo hauled and spread an average of <br />18 inches of topsoil on each of the Phase II reclamation blocks included in SL-04. <br />During the 15 June 2010 inspection the Division dug five topsoil test holes in the East Pit Phase <br />II area. During the Division's 19 July 2010 inspection an additional 12 topsoil test holes were <br />dug in the East Pit Phase II area, 5 topsoil test holes in the dug in the Section 16 Pit Phase II area <br />and 12 topsoil test holes were dug in the West Pit Phase II area. Details regarding the topsoil <br />depths from the individual holes can be found in a chart in the 24-27 August 2010 inspection <br />report. The locations of these topsoil test holes can be found in the Division's 24-27 August <br />2010 inspection report on Inspection Maps 9-12. The average topsoil replacement depth for the <br />Proposed Decision and Findings of Compliance 2 May 2011 <br />Partial Phase I/II Bond Release SL-04 Page 8