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<br />Inspection Topic Summary <br />NOTE: Y=Inspected N=Not Inspected R=Comments Noted V=Violation Issued NA=Not Applicable <br />N - Air Resource Protection <br />N - Availability of Records <br />R - Backfill & Grading <br />N - Excess Spoil and Dev. Waste <br />N - Explosives <br />N - Fish & Wildlife <br />N - Hydrologic Balance <br />N - Gen. Compliance With Mine Plan <br />N - Other <br />N - Processing Waste <br /> <br />N - Roads <br />N - Reclamation Success <br />N - Revegetation <br />N - Subsidence <br />N - Slides and Other Damage <br />N - Support Facilities On-site <br />N - Signs and Markers <br />N - Support Facilities Not On-site <br />N - Special Categories Of Mining <br />N - Topsoil <br /> <br /> <br />COMMENTS <br /> <br />This was a bond release insepction of the of the Colowyo Mine conducted by Zach Trujillo of Colorado Division <br />of Reclamation, Mining and Safety (DRMS) on July 25,2017. Colowyo Coal Company L.P. (Colowyo) has <br />requested a total of 129.6 acres located in the East and West Pit for phase I bond release (SL-11). The inspection <br />focused entirely on backfilling and grading requirements as approved in Colowyo’s PAP. Tony T ennyson <br />representing Tri-State Generation and Transmission Association (Tri-State), Angela Aalbers and Kurtis Blunt <br />representing Colowyo Coal Company (Colowyo) accompained the inspection as well as Tom Medlin of the Office <br />of Surface Mining (OSM). Representatives of the Bureau of Land Management (BLM) and the Colorado State <br />Land Board (SLB) were invited but did not attend the inspection. The weather was cloudy with intermittent rain <br />throughout the day and ground conditions were lightly saturated. Temperatures for the day were around seventy <br />degrees fahrenheit. <br />BACKFILL and GRADING – Rule 4.14 <br />Contemporaneous Reclamation 4.14.1; Approximate Original Contour 4.14.2; Highwall Elimination 4.14.1(2)(f); <br />Steep Slopes 4.14.2, 4.27; Handling of Acid and Toxic Materials 4.14.3; Stabilization of Rills and Gullies 4.14.6: <br />As noted earlier, a total of 129.6 acres have been requested for Phase I bond release. Of the 129.6 total acres, 30.7 <br />acres are in the East Pit and the remaining 98.9 acres are in the West Pit. To determine compliance with <br />Colowyo’s approved approximate original contour (AOC) in the SL-11 area, elevation data provided in the SL-11 <br />Bond Release application was compared to GPS data collected by the Division. Twenty two points were selected <br />along three transect lines approximately every 300 feet. Two transects with a total of 16 points were taken along <br />the West Pit and one transect with a total of 6 points were taken along the East Pit. These points were selected by <br />utilizing Exhibit 1 of the SL-11 application. Points were placed at selected contour elevations in ArcGIS (to try to <br />cover the majority of the area), and those points were then downloaded into a Panasonic FZ-G1 tablet computer. <br />However, it was discovered at the time of the inspection, elevations data cannot be gathered using the Panasonic <br />tablet. The Division then switched to a Trimble R10 GNSS (R10) surveying unit. Points were then navigated to <br />using the Panasonic tablet and then taken using the R10. The points collected at the site were downloaded from the <br />Trimble into Pathfinder Office and converted into a point shape file to utilize in ArcGIS. <br /> <br />The static precision of the R10 is 3.5 mm +0.4 ppm RMS and is on a localized geoid. For comparison reasons, a <br />known point was collected at the Colowyo Mine office to determine a correction factor for the elevation collected <br />with the R10. In Colowyo’s coordinate system (UTM NAD 27 Colorado State Plane) the elevation is 7262.91’ at <br />the known base station and was measured by the Division at an elevation of 7261.83’. Since the difference <br />between the two elevations is so minimal and most likely due to user error, no correction factor was added to the <br />elevation points measured for SL-11.