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Keenesburg Strip Mine (C-1981-028) MT-07 <br /> <br /> <br />Page 2 <br /> <br /> <br />Section I - Mine History and the Environment <br /> <br />Mine Status and History <br /> <br />The Keenesburg Strip Mine is nearing the final phases of reclamation. <br /> <br />Coal extraction operations began in 1980 and ceased by 2001. During active surface coal extraction, <br />the Number 7 Seam of the Laramie Formation was mined. <br /> <br />Reclamation work previously included the controlled disposal of ash and mine waste rock as a portion <br />of the backfill of mine pits. The importing of ash was completed by CEC in April 2016. <br /> <br />Some information on the mine’s environment, operations, and reclamation activities are provided <br />below. More detailed information about the mining and reclamation operations can be found in the PAP <br />on file at the Division offices, located at 1313 Sherman Street, Room 215, in Denver, Colorado. <br /> <br /> <br />Description of the Environment <br /> <br />The Keenesburg Strip Mine is located on private lands within Weld County, Colorado. It is <br />approximately six miles north/northeast of the town of Keenesburg within Section 25, Township 3 <br />North, Range 64 West of the 6th Principal Meridian. (A very small portion of the site is in Section 36 <br />of T3N, R64W.) <br /> <br />The current permit boundary contains approximately 226 acres. According to the 2018 Annual <br />Reclamation Report, approximately 443 acres have been disturbed over the life of the mine, and <br />approximately 263.7 acres have been previously approved for Phase III bond release. <br /> <br />Geology, Soils and Topography <br />The permit area is located on level to gently rolling topography consisting of fine sand, which is wind- <br />deposited material overlying weathered residual shale. The sand varies in depth from about 5 feet to <br />20 feet, is highly to moderately permeable, and is highly susceptible to wind erosion. The flat-lying <br />Number 7 coal seam was overlain by 60-180 feet of overburden consisting of yellow-brown and gray <br />to blue gray soft carbonaceous shale and clay interbedded with sandstone and shaley sandstone. At the <br />base of the Laramie formation is the Fox Hills member, a cross-bedded gray to buff sandstone, which <br />is slightly or well cemented. <br /> <br />Surface and Groundwater <br />Because of the low relief and deep, well-drained soils, there is virtually no surface runoff. No streams, <br />springs or seeps exist in the area. All water flows subsurface through aeolian deposits to Ennis Draw, <br />a topographic swale (ephemeral drainage) located along the eastern boundary of the permit area. Ennis <br />Draw appears to be a complex, braided, ancient stream bed that has been covered by windblown sand. <br />The draw discharges several miles to the north into Box Elder Creek.