2015-12-10_INSPECTION - M1984185

Home Browse Search

PERMIT #: M-1984-185 INSPECTOR’S INITIALS: AME INSPECTION DATE: December 10, 2015 Page 2 of 9 OBSERVATIONS This was a normal monitoring inspection of the Ellis Allen Pit (Permit No. M -1984-185) conducted by Amy Eschberger of the Division of Reclamation, Mining and Safety (Division). Mr. John DeWitt and Mr. Mark McHone represented the operator, Lincoln County during the inspection. The site is located approximately 14.5 miles north of Genoa, Colorado. Access to the site is off of Co Rd 31. The site is situated on the South Fork of the Arickaree River, which only flows during heavy storm events. When carrying water, the river flows eastward. The affected land is owned by Ellis Allen. The approved post-mining land use is rangeland. This is a 110c operation permitted for 8.2 acres (see enclosed Google Earth image of site) to mine sand and gravel for use in county road maintenance. This is an intermittent operation. The approved permit area includes a section of the Arickaree River (to the south) where material is mined from the creek bed, and a portion of a ridge (to the north) where clay is mined from the top of the ridge. Material excavated from the river channel is stockpiled in the relatively flat area just north of the river. The approved rec lamation plan for this site includes grading all disturbed slopes to a 3H:1V gradient or flatter, ripping any compacted areas of disturbed land outside of the river bed, replacing topsoil at an average depth of 6 inches across disturbed land in the clay pit area, and revegetating all disturbed land outside of the river bed with a rangeland seed mixture. If there is not enough topsoil on site for reclamation, additional topsoil will be imported from county road ditch cleaning operations. The Division recently approved a Technical Revision (Revision No. TR-04) on 03/30/2015 to update the mining plan map and reclamation plan map to more accurately define the permit boundary using GPS coordinates. This was part of the county’s recent initiative to make sure all of their permitted sites are in compliance with regards to properly delineating the approved permit boundaries. At the time of the inspection, the weather was partly cloudy and breezy, and no standing water was observed on site. The creek bed was dry. A permit sign was posted at the main site entrance off of Co Rd 31 (Photo 1). The permit boundary was properly delineated with metal posts (Photo 2). The site was not active at the time of the inspection, and no equipment was stored on site. However, according to the operator, the site is active every year, which is in compliance with its intermittent status. The Division observed a shallow depression (approximately 2 feet in depth) in the river bed where material was extracted and pushed up to the northern bank (Photo 3). This depression was approximately 300 feet in length down the river channel. Outside of this depression, the river bed appeared to be relatively flat and even. The river channel upstream and downstream (Photo 4) of the mining area appeared to be preserved, showing no evidence of erosion. Two material stockpiles were stored in the flattened area north of the river (Photo 5). All disturbed slopes have been graded to a 3H:1V or flatter gradient. The ridge side north of the river exhibited some erosional damage in the form of rilling (Photo 6) and a few small gullies (Photo 7). The Division recommends the operator continue to monitor this slope and repair erosional damage as needed to help protect slope stability. Native grasses (primarily sand dropseed, blue grama, and buffalograss) are volunteering across most of the disturbed land outside of the river bed (Photos 8 and 9), including across the material stockpiles, except for on portions of the ridge side where vegetative cover is patchy. The clay pit area at the top of the ridge (Photos 10 and 11) appeared to have been reclaimed, as it was graded to nearly flat and had a good establishment of native grasses (e.g., sand dropseed, blue gramma, western wheatgrass, buffalograss) and a few shrubs (primarily yucca and broom snakeweed). Remaining topsoil was left in small low- lying mounds along the eastern edge of the reclaimed clay pit area (Photo 12). These small topsoil mounds have a good establishment of grass cover which makes them blend in fairly well with surrounding topography. As long as the operation does not re-disturb the top of the ridge, this portion of the permit area appears to have been reclaimed in accordance with the post-mining land use of rangeland. Overall, the site appeared to be stable. No problems were observed.