2019-10-22_GENERAL DOCUMENTS - C1981019

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observed throughout the length of the East Side Collection Ditch and is stabilized with substantial vegetative growth. The ditch conformed to the adjacent previously released Phase III areas of the East Pit and no issues were observed. The Gulch A Pond was inspected and at the request of the landowner, the pond is approved as a permanent structure in support of the post-mining land use. The pond is stable with vegetated embankments and remains functional. At the time of the inspection, the pond held minimal water. The Division also reviewed previous inspections of the Gulch A Pond as part of SL-16 process and the pond has had no items of concerns or previous issues. For the East Pit, East Side Collection Ditch, and Gulch A Pond, the Division finds that the Colowyo Mine has achieved a post-mining surface that conforms to the approved post-mining topography and resembles the general surface configuration of the land prior to mining. All highwalls have been eliminated and the reclaimed lands blend in well with the adjacent undisturbed slopes. No settling, slumping or cracking of the backfill were noted in the partial Phase I Bond Release area in the East Pit as well as the East Side Collection Ditch and Gulch A Pond. During the Division's review of the reclamation liability cost estimate, it was discovered that the 3.3 acres of EP058 being requested for Phase I bond release has no reclamation cost associated to it and the Division holds no bond monies associated with the disturbance. The 3.3 acres was originally partially Phase I bond released under SL-4 as part of the Section 16 Pit, but was re-disturbed during the reclamation of the East Pit highwall. This re-disturbed acreage was missed in the Division's acreage tracking and reclamation liability cost estimates. Due to this error,the Division will not be releasing any monies associated with the completion of reclamation for 3.3 acres for partial Phase I. Phase II Topsoil Replacement A total of 12 topsoil verification holes were dug and measured during the August 2019 inspection prior to the SL-16 bond release inspection in order to verify topsoil depths within the areas being requested for Phase II of the SL-16 application. Colowyo is approved for variable topsoil depth placement and as per Colowyo's PAP, "Topsoil will... ...be redistributed and graded to a variable replacement depth following the general rule of thin topsoil (<6) inches on ridge tops to gradually thicker topsoil moving down the slopes to the drainage bottoms for the grazingland land use targeted areas. Sagebrush Steppe areas will ideally receive an average of approximately 4 inches of topsoil that will likely be more uniform application to encourage proper seeding depth and overall shrub establishment conditions." Holes were dug individually with a shovel at randomized predetermined locations. All topsoil verification holes were dug to a minimum of 9 inches or until topsoil was no longer visible. Holes were dug to a depth greater than 9 inches when specified depth average was greater as stated under Section IV of the SL-16 application. The topsoil holes were then immediately backfilled after the depth of topsoil was Proposed Decision and Findings of Compliance October 22,2019 Partial Phase I,II and III Bond Release SL-16 Page 9