Laserfiche WebLink
release application was compared to GPS data collected by the Division. A total of six GPS <br /> points were taken,three along the East Pit and three along the West Pit. GPS points were placed <br /> at selected transects between approximately 200 - 300 feet intervals and along contour elevations <br /> in ArcGIS and those points were then downloaded on ArcGIS for ESRI Collector(Collector). <br /> Locations of these points are shown on Figure 2 of this document. During the bond release <br /> inspection, the Division navigated to the points using the data in Collector and a GPS data point <br /> was collected at each predetermined location along the transect. Each reclamation parcel was <br /> also visually inspected to ensure the area was graded and blended in with the adjacent reclaimed <br /> areas. During the inspection, no signs of erosion or issues were encountered. <br /> For comparison reasons, a known point was collected at the Colowyo Mine office to determine a <br /> correction factor for the elevation of the bond release areas collected with the GPS. In <br /> Colowyo's coordinate system (UTM NAD 27 Colorado State Plane)the elevation is 7,261' at the <br /> known base station and was measured by the Division at an elevation of 7,232'. The difference <br /> between the elevations was 29 feet which will be used as the correction factor. <br /> The elevation data collected for the East and West Pit by the Division was compared to elevation <br /> information provided in the SL-20 Bond Release application and shown on Table 4 of this <br /> document. After comparison, all elevation points taken by the Division were found to have an <br /> average deviation of 6 feet from the elevations shown on SL-20 Map 1 and Figure 1 of this <br /> document. Given the expanse of the mine site and the steepness of the terrain at Colowyo, as <br /> well as the error contributed by the user,the Division determined that the difference in elevation <br /> is acceptable. <br /> Summary and Conclusions <br /> The Division has completed its review and evaluation of the SL-20 partial Phase I Bond Release <br /> application submitted by Colowyo for the Colowyo Mine. The Division proposes to approve this <br /> Partial Phase I Bond Release on 18 acres for portion of the West Pit. Based upon a review of the <br /> mine permit,the applicant's bond release application, and site inspections,the Division finds that <br /> Colowyo has completed drainage reestablishment with the approved post-mining topography that <br /> resembles the general surface configuration of the land prior to mining, and supports the <br /> approved post-mining land use. The reclamation parcels required under SL-20 conforms to post- <br /> mining contours as shown on the approved Postmining Topography Map of the PAP (Map 19 <br /> and 19B) and was stable at the time of the inspection. The Division finds that Colowyo has <br /> achieved the requirements for partial Phase I Bond Release at the Colowyo Mine. <br /> V. PROPOSED DECISION <br /> Based on the observations in Section IV above,the Colorado Division of Reclamation,Mining, and <br /> Safety proposes to approve Colowyo's request for a partial Phase I Bond Release for the Colowyo <br /> Mine. This proposed decision will release the applicant of Phase I reclamation liability on 18 acres <br /> for portion of the East and West Pits, as shown on Figure 1 at the end of this document. <br /> Proposed Decision and Findings of Compliance May 28,2021 <br /> Partial Phase I Bond Release SL-20 Page 6 <br />