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trending cross-section in the East Pit using ArcMap and compared field data with the approved <br />post-mining topography for this cross-section. The Division found that the as-built topography <br />along cross-sections 1, 2 and A differed from the approved post-mining topography by an <br />average of 2.1 feet, 1.4 feet and 11.5 feet, respectively. The Division finds that the Colowyo <br />Mine has achieved a post-mining surface that conforms to the approved post-mining topography <br />and resembles the general surface configuration of the land prior to mining. All highwalls have <br />been eliminated and the reclaimed lands of the East Pit blend in well with the adjacent <br />undisturbed slopes. No erosional problems were noted in the Phase I Bond Release areas of the <br />East Pit and no settling, slumping or cracking of the backfill was observed. <br />The Division created three cross-sections in the West Pit using ArcMap and compared the field <br />data with the approved post-mining topography. These cross-sections were labeled B-B' <br />(southwest-northeast trending), C-C' (north-south) and D-D' (east-west). The Division found <br />that the as-built topography of the West Pit Phase I Bond Release areas, along cross-sections B, <br />C and D, differed from the approved post-mining topography by an average of 7.2 feet, 11.5 feet <br />and 4.0 feet, respectively. The Phase I Bond Release area of the West Pit is an approved <br />permanent, excess spoil fill. Details regarding the West Pit Fill can be found in the approved <br />permit application. The Division finds that the Colowyo Mine has achieved the approved post- <br />mining topography in the Phase I areas of the West Pit. No erosional problems were noted in the <br />Phase I Bond Release portions of the West Pit and no settling, slumping or cracking of the fill <br />material was observed. <br />The Division created two cross-sections in the Section 16 Pit using ArcMap and compared the <br />field data along these cross-sections with the approved post-mining topography. The Division's <br />cross-sections were labeled E-E' (southwest-northeast trending) and F-F' (east-west). The <br />Division found that the as-built topography of the Section 16 Pit along cross-sections E and F <br />differed from the approved post-mining topography by an average of 5.8 feet and 4.1 feet, <br />respectively. The Division finds that the Colowyo Mine has achieved a post-mining surface that <br />conforms to the approved post-mining topography and resembles the general surface <br />configuration of the land prior to mining. All highwalls have been eliminated and the reclaimed <br />lands of the Section 16 Pit blend in well with the adjacent slopes. No erosional problems were <br />noted in the Phase I Bond Release areas of the Section 16 Pit and no settling, slumping or <br />cracking of the backfill was observed. <br />Drainage Reestablishment <br />While the Division did inspect and verify the permanent, post-mining drainage channels in the <br />Phase I Bond Release areas of the East Pit, West Pit and Section 16 Pit, none of these drainage <br />channels are being released in the SL-04 bond release. The reason these drainages are not being <br />included is because they still receive runoff from disturbed mine areas. <br />The Phase I area of the East Pit drains into the Gulch A Ditch and, ultimately, into the Gulch A <br />Pond. During the inspection the Division walked the Gulch A Ditch from approximately station <br />59+62 to approximately station 17+69 and collected elevation data along that portion of the <br />Proposed Decision and Findings of Compliance 2 May 2011 <br />Partial Phase 1/11 Bond Release SL-04 Page 7