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The evaluation of the bond release application included the bond release inspection, an office <br /> review of the permit requirements and regulatory criteria, and review of past inspection reports. <br /> The bond release inspection was conducted on September 5, 2019. Several items were reviewed by <br /> the Division during the technical evaluation of the bond release application before, during, and <br /> after the inspection, including: the post-mining topography and cross-sections of backfilled and <br /> graded areas. <br /> During the SL-16 Bond Release inspection, participants walked the bond release request area to <br /> allow for visual assessment of compliance with pertinent requirements. <br /> Phase I <br /> For SL-16, observations were made during the bond release inspection with regard to <br /> approximate original contour and stability of the reclaimed landscape. To determine compliance <br /> with Colowyo's approved approximate original contour(AOC) in the SL-16 areas, elevation data <br /> provided in the SL-16 Bond Release application was compared to GPS data collected by the <br /> Division for the 3.3 acres requested for partial Phase I Bond Release. Due to the small area, only <br /> two elevations points (see Figure 3) were collected by GPS along elevation lines shown on Map <br /> 1 of the SL-16 application in the East Pit. During the bond release inspection, the Division <br /> navigated to the area using the data in ESRI Collector and a GPS data point was collected at each <br /> site with a Bad Elf GNSS (Bad Elf) surveying unit. The reclamation parcel was also visually <br /> inspected to ensure the area was graded and blended in with the adjacent reclaimed areas. <br /> During the inspection, no erosional features were observed along the requested Phase I are in the <br /> East Pit. No issues were observed at the visually inspected reclamation parcels. <br /> The static accuracy of the Bad Elf is approximately 1 meter with SBAS+PPP and is on a <br /> localized geoid. For comparison, a known point was collected at the Colowyo Mine office to <br /> determine a correction factor for the elevation of the bond release areas collected with the Bad <br /> Elf. In Colowyo's coordinate system (UTM NAD 27 Colorado State Plane) the elevation is <br /> 7,261' at the known base station and was measured by the Division at an elevation of 7,281' with <br /> the Bad Elf. The difference between the elevations was 20 feet which will be used as the <br /> correction factor. <br /> The elevation data collected for the East Pit by the Division was compared to elevation <br /> information provided in the SL-16 Bond Release application. After comparison, all elevation <br /> points taken by the Division were found to have an average deviation of 6 feet from the <br /> elevations shown on SL-16 Map 1. Given the expanse of the mine site and the steepness of the <br /> terrain at Colowyo, as well as the error contributed by the user, the Division determined that the <br /> difference in elevation is acceptable. <br /> During the inspection, the Division navigated the entire East Side Collection Ditch with the GPS <br /> assistance of ESRI Collector. The East Side Collection Ditch has been approved as a permanent <br /> structure in support of the post-mining land use as requested by the landowner. No erosion was <br /> Proposed Decision and Findings of Compliance October 22,2019 <br /> Partial Phase I,II and III Bond Release SL-16 Page 8 <br />