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Revision of Keenesburg Mine Predictive Equations for Vegetation Cover and <br />Herbaceous Production Revegetation Success Criteria <br />Coors Energy Company (CEC) commissioned Michael Savage (Savage and Savage) to <br />conduct a further review and analysis of the development of the original predictive <br />equations for revegetation success criteria for vegetation cover and herbaceous production <br />that were approved by the Colorado Division of Reclamation, Mining and Safety <br />(CDRMS) under Technical Revision 37 (TR37). Based on the current requirement of <br />CDRMS that Colorado Department of Agriculture noxious listed plant species (listed <br />species) not be included in any comparison of revegetated /reclaimed areas and <br />revegetation success criteria for vegetation cover or herbaceous production to assess <br />reclamation success; Mr. Savage reanalyzed and recalculated the predictive equations, <br />removing the offending species where they have been included in the original data <br />employed to develop the predictive equations and therefore, the final revegetation success <br />criteria for the Keenesburg Mine. <br />CDRMS first informed CEC that listed species could not be counted in the comparison of <br />reclaimed area vegetation cover or total herbaceous production during the review of <br />Phase III bond release application SL -06. Subsequently, CDRMS staff commented on the <br />inclusion of listed species in the 2011 monitoring of reclaimed and revegetated areas at <br />the Keenesburg Mine (2011 AHR Report). <br />Without acknowledging the merit of the CDRMS interpretation, the more significant <br />issue is that the revegetation success criteria developed for the Keenesburg Mine <br />(predictive equations for vegetation cover and herbaceous production) were developed <br />with the inclusion of the now prohibited listed species, thereby creating an inherent <br />inequality. When discussed with CDRMS, this inherent inequality was acknowledged, <br />and the parties agreed to reevaluate and recalculate the predictive equations to reflect <br />discounting of listed species. <br />Method of Development of the Original Predictive Equations <br />And Subsequent Revegetation Success Criteria <br />The first step in revising the predictive equations was to review the data and revisit the <br />specifications and negotiations that led to the finalization and approval of TR37 (wherein <br />the predictive equations were developed to replace use of the Osgood Sand Reference <br />Area). The suite of data that were used as well as the conditions and restrictions that <br />were employed, were obtained from the record of sampling at the Osgood Sand Reference <br />Area between the years 1994 and 2005, and correspondence and meeting records between <br />CDRMS, CEC, and Savage and Savage. <br />In development of the predictive equations and the subsequent revegetation success <br />criteria for vegetation cover and herbaceous production, a measurable parameter to <br />compare the two vegetation parameters was developed. In this case it was determined <br />that seasonal precipitation, specifically, total precipitation measured at the mine site from <br />September to the following calendar year July (August was not included as sampling <br />Coors Energy Company Keenesburg Mine <br />Response to CDRMS 2011 AHR Review: Revision of Revegetation Criteria <br />Page 1 <br />