_INSPECTION - C1992080 (13) - Laserfiche WebLink

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Carbon Junction channel. The reconstructed section of the channel was in good shape with large rock riprap in place and the two 5 `/2 -foot diameter culverts extending underneath the haul road. Vegetation debris and sediment has been washed into the channel,but the culverts contained little sediment,indicating no recent significant flow through the culverts. Sediment control. The vegetative cover established on the disturbed areas of the Carbon Junction Mine appears to be effectively controlling erosion. With the exception of one gully on the reclaimed North Pit slope (see discussion of Slides and Damage), no significant gullies or sediment fans were found on the site. Erosion on the disturbed areas of the site appears to be occurring at a rate similar to adjoining undisturbed lands. The base of the North Pit reclaimed slope is contoured to act as a grass filter for trapping sediment in runoff coming off of the slope where the south half of the North Pit was approved as a small area exemption in TR-14. This grass filter terrace was in good condition. Backfilling and Grading Backfilling, grading, topsoil replacement, and revegetation appeared to have been completed in all areas within the permit area except topsoil stockpiles 4 (north of Pond 1), 7 (southeast of Pond 2), and 8 (south of Pond 1); the two sediment control ponds(1 and 2); the diversion ditch that extends approximately 500 feet along the eastern and southern edge of the Equipment Storage Area; the collection ditch that extends approximately 500 feet along the east side of the paved haul road, southwest of Topsoil Stockpile#7; and boreholes 17-1, 94-1, and 95-1. Support Facilities No problems were found in the Equipment Storage Area at the south end of the permit area. Equipment previously stored there has been removed from the site, supporting a finding for Phase I release of bond held for equipment removal. Topsoil Stockpiles 4(immediately north of pond 1)and 8(immediately south of pond 1)were well-vegetated,are not gullied, and do not have weed problems. Topsoil replacement depths in the bond release area were previously verified during the June 2008 inspection in the Equipment Storage Area and in the Permanently Reclaimed Spoil Area. All locations had more than one foot of topsoil, consistent with the approved reclamation plan. Replaced topsoil depths in the North Pit area were observed during topsoil replacement in 2006 and were found to be more than the one-foot required thickness. Revegetation The areas that were backfilled, graded,topsoiled, seeded, and mulched in summer 2006 had initially developed a nurse crop of sterile wheat/oat hybrid, a product called Regreen. This nurse crop has since given way to a good cover of wheat, orchard, brome, and rye grasses. Yellow sweet clover was especially abundant throughout the site, as it is elsewhere in western Colorado this year. Standing cover, vegetative litter, and rock cover appeared adequate for erosion control in the bond release area. There were a few areas of less than 1/4 acre where vegetative cover appeared either significantly less than or greater than 50%, but overall the cover in the bond release area appeared consistent with cover sample data reported in the bond release application(>60%), after taking plant dormancy into account. 5