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Proposed Decision and Findings of Compliance <br />Partial Phase I, II and III Bond Release SL-23 Page 7 of 16 <br /> <br />Evaluation and inspection of the reclaimed areas was based on the specific requirements of the reclamation plan and <br />the functional requirements of the post-mining land use. Criteria for bond release included the following. <br /> <br />1. The reclamation supports the approved post-mining land use (Rule 4.16.1); <br />2. All areas requested for Phase III bond release meet the requirements for Phase I and Phase II bond release <br />or have previously received Phase I and Phase II bond release approval. <br /> <br />All contributing acreage to the Streeter Ditch and Streeter Pond has either been Phase III bond released or has <br />been removed from the watershed following final construction of the Upper and Lower Section 3 Sediment <br />Ponds approved in 2022 under TR-155. A small area exemption for a grass filter, located just south of the <br />Streeter Ditch, was approved for a small area exemption under TR-155. Upper and Lower Section 3 Ponds are <br />non-discharging structures. As-built and SEDCAD demonstrations for the Upper and Lower Section 3 Ponds <br />were approved in 2024 under TR-164. <br /> <br />III. OBSERVATIONS AND FINDINGS <br /> <br />The following discussion of observations and findings focuses on the results of the construction of a permanent <br />structure, Streeter Pond, in support of the approved post-mining land use and drainage establishment for the <br />Streeter Ditch as requested in the SL-23 application. During the SL-23 bond release inspection, participants <br />walked the bond release request area to allow for visual assessment of compliance with pertinent <br />requirements. Observations were made during the bond release inspection with regard to approved design <br />specifications, elevational profiles, and on the ground functionality. <br /> <br />The evaluation of the bond release application included the bond release inspection, an office review of the <br />permit requirements and regulatory criteria, and review of past inspection reports. Several items were <br />reviewed by the Division during the technical evaluation of the bond release application before, <br />during, and after the inspection, including as-built designs and sedimentology demonstrations as <br />required by Rule 3.03.1 and approved in the Colowyo PAP. <br /> <br />PHASE I <br /> <br />For the 5.5 acres requested for partial Phase I, II and III Bond Release under SL-23, observations were made <br />during the Division’s bond release inspection with regard to approximate original contour and stability of the <br />reclaimed landscape and ditch. To determine compliance with Colowyo’s approved approximate original <br />contour (AOC) in the SL-23 areas, elevation data provided on Figure 1 SL-23 Location Map was compared to <br />GPS data collected by the Division. Nine elevation points along Streeter Ditch and one point at Streeter Pond <br />were collected by GPS at survey stations and coordinate locations specified in Table 4. During the bond <br />release inspection, the Division navigated to the points using the ArcOnline Field Maps application. A GPS <br />data point was collected at each point (Figure 2), utilizing an iPhone 13 as the surveying unit. Design <br />measurements were also taken at each point to determine channel width, channel depth, and channel material <br />(Table 1) to be checked against the SEDCAD design and as-built profiles for the ditch (Table 2). <br /> <br />Elevation point data was initially collected at the Division’s October 30th inspection. During post-processing of <br />this data, it was apparent that the device used to collect elevation points had a technical error, as elevation <br />points collected did not match recent USGS LiDAR imagery or topographic maps for the area. Initial <br />elevations were off in some locations by ~160 feet. This discrepancy did not match the observed elevation <br />profile of the Ditch and approved post-mining topography. The Division suspects that satellite access is limited <br />in the steeper areas of the valley in which Streeter Ditch is located and was producing the reading error in <br />elevation. Therefore, the Division re-tested for elevational points during a follow up November 20th inspection.