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<br />Proposed Decision and Findings of Compliance October 2018 <br />Partial Phase II and III Bond Release SL-14 Page 7 <br />During the partial Phase II and III Bond Release inspection, participants walked through each of <br />the bond release request parcels to allow for visual assessment of compliance with pertinent <br />requirements as described above in Section III of this document. A summary of the observations <br />are discussed below and the details are further discussed in the associated inspection report. <br /> <br />Phase II <br /> <br />Topsoil Replacement <br /> <br />A total of 70 topsoil verification holes were dug and measured during the June 2018 inspection <br />in order to verify topsoil depths within the areas being requested for Phase II of the SL-14 <br />application. Colowyo is approved for variable topsoil depth placement and as per Colowyo’s <br />PAP, “After the final regrading is completed, the topsoil will be reapplied as shown on the <br />disturbed land areas shown on the Topsoil Handling Map (Map 28 and 28A). Future topsoil <br />redistribution will be done at an average depth of eight (8) inches based on the volumetric <br />analysis of available materials and areas as presented in Rule 2.05.” Holes were dug individually <br />with a shovel at randomized predetermined locations. Each of the 70 topsoil verification holes <br />were dug to a minimum of 8 inches in depth. The topsoil hole was then immediately backfilled <br />after the depth of topsoil was verified. Figure 3 show the location of each hole. Of the 70 <br />topsoil verification holes dug, five were found to be between 4 – 8 inches in depth while the <br />remaining were found to be 8+ inches. <br /> <br />Vegetation Cover <br /> <br />The Colowyo Mine uses two reference areas for the comparison of success of their reclamation <br />parcels. The reference areas are the sagebrush reference area (established 1981) and the mountain <br />shrub reference area (established in 1980, which is further separated into a mesic aspect and a xeric <br />aspect). Success standards are based on weighted average of the pre-mining vegetation <br />communities in each reclamation block (as shown on Map 3 and 4 in Colowyo’s PAP). <br /> <br />Permit Page 4.15-18 states that the “…herbaceous cover of the revegetated area will be considered <br />adequate for final bond release if it is not less than 90% of the herbaceous cover as determined from <br />the reference areas with 90% statistical confidence utilizing a standard student’s statistical t-test <br />comparison of the means.” <br /> <br />During the June 2018 inspection, the Division observed three areas of heavy cheatgrass which is <br />classified as a List C noxious weed. The location of these areas were within reclamation parcels <br />EP050, EP051 and WP015. The perimeter of the cheatgrass concentrations were walked with GPS <br />and a rough area was measure for EP050 and EP051. The cheatgrass areas are approximately 0.22 <br />acres for EP050 and 0.96 acres for EP051. When comparing these cheatgrass concentrated areas to <br />the relative size of their associated reclamation parcel, the Division considers these measured areas <br />to not be representative. The cheatgrass areas consisted of less than 0.3% of the total area for <br />EP050 and 3.1% for EP051. Reclamation parcel WP015 was only visually inspected and due to the <br />size of WP015 (101.8 acres), the cheatgrass concentrated area was considered not representative of