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COLORADO <br />�/ Division of Reclamation, <br />® Mining and Safety <br />Department of Natural Resources <br />1313 Sherman Street, Room 215 <br />Denver, CO 80203 <br />Memorandum <br />Date: August 14, 2020 <br />To: Rob Zuber, DRMS <br />From: Janet Binns, DRMS <br />RE: Keenesburg Mine, C1981-028, TR47 Review <br />I have conducted a review of .Coors Energy Company's application to revise the seasonality requirement of <br />the species diversity success standard for the Keenesburg Mine, TR47. The post -mining land use is <br />Rangeland. <br />CEC provided extensive justification and supporting information regarding the propriety of the proposed <br />reclamation success standard for species diversity for the Keenesburg Mine. The approved seed mix is <br />heavily weighted to the establishment of warm season grass species, and minimizes the potential for <br />cool season grass establishment. <br />The NRCS Ecological Site Descriptions (ESD) also show a preponderance of the Deep Sand ESD and <br />Rolling Sand ESD, as having a higher percentage of warm season grass species. Continuous grazing <br />with inadequate time for recovery will favor more shrubs, short grasses and unpalatable species in both <br />of these ESDs. The Osgood Reference area was heavily dominated by Sand sage (2000 to 2004 <br />sampling) demonstrating that the OSRA may not have been indicative of a properly managed range site. <br />Based upon the 30 plus years of meteorological data (temperature and precipitation) for the mine site, <br />the weather patterns favor establishment and sustaining of a warm season grass dominant community. <br />The OSRA measured the presence of Green needlegrass in the 1994 to 2004. CEC provided forage <br />value discussion regarding the warm season and cool season species present. The data demonstrated <br />that the warin season grass species present in the reclaimed parcels were providing significantly greater <br />forage value that of the cool season grass species. It is logical to conclude from the supporting <br />documentation provided by CEC that the forage value contributed by cool season grass species versus <br />warm season grass species in the reclamation would be insignificant. By removing the seasonality <br />requirement in the species diversity success standard, reclamation success on the reclaimed parcels at <br />the Keenesburg Mine will still be adequately demonstrated, and the post mining land use of Rangeland <br />is not diminished. <br />The Division finds that the change to the seasonal requirement for the species diversity standard for the <br />Keenesburg Mine still meets the requirement of Rule 4.15.8 (6). <br />of • cOto <br />1313 Sherman Street, Room 215, Denver, CO 80203 P 303.866.3567 F 303.832.8106 http://mining.state.co.us <br />Jared Polis, Governor I Dan Gibbs, Executive Director I Virginia Brannon, Director <br />'1876 <br />