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EXECUTIVE SUMMARY <br />Quantitative vegetation monitoring of Reclamation Areas 23, 29, 30, and 31 revegetated <br />between 2002 and 2009 at the Coors Energy Company (CEC) Keenesburg Mine, was <br />conducted in August 2012. Vegetation cover by species, herbaceous production, and <br />species composition were sampled. Comparisons were made between total vegetation <br />cover and total herbaceous production means from the reclamation areas and predicted <br />values calculated from the approved final revegetation success equations, based on on- <br />site precipitation from September 2011 to July 2012. Predictive equations approved in <br />Technical Revision 37 (TR37) establish the final revegetation success criteria for total <br />vegetation cover and total herbaceous production for the mine. <br />The sample means for total vegetation cover from Reclamation Areas 23 and 29 in 2012 <br />(32.00 and 30.60 %, respectively) met the current final revegetation success value of 32.47 <br />percent total vegetation cover by being greater than 90% of the cover standard. The <br />sample mean for total vegetation cover from Reclamation Area 30 met the current final <br />criterion for total vegetation cover after statistical evaluation. Reclamation Area 31 <br />vegetation cover did not meet the current final revegetation success criterion after <br />evaluating the means using a Student's t -test. <br />The mean total herbaceous production values from the reclamation areas (Area 23, 143.0 <br />g /m Area 29, 93.2 g /m Area 30, 124.1 g /m and Area 31, 77.5 g /m were greater <br />than 90 percent of the predicted 84.7 g /m total herbaceous production success criterion, <br />thereby meeting the final success criterion for total herbaceous production this season. <br />Species composition of the reclamation areas was also evaluated from a final success <br />criterion perspective. Reclamation Areas 23 and 29 had three qualifying warm season <br />graminoids, but each lacked a qualifying cool season graminoid to meet the final species <br />composition criterion. Reclamation Area 30 had four perennial warm season graminoids <br />and two perennial cool season graminoids, thereby exceeding the final species <br />composition requirements. Reclamation Area 31 had one perennial warm season <br />graminoid and two perennial cool season graminoids meeting the species composition <br />requirements this season, but lacked two qualifying perennial warm season graminoids to <br />satisfy all requirements of the final revegetation success criteria for species composition. <br />During the review of the 2011 vegetation monitoring report, the Colorado Division of <br />Reclamation, Mining and Safety (CDRMS) expressed concern that certain plant species <br />listed as weeds by the Colorado Department of Agriculture were included in total <br />vegetation cover and total herbaceous production reporting. CDRMS dictated that these <br />species not be included in evaluations for revegetation success. As these ineligible <br />species were included in the establishment of the standards from TR37, CEC requested <br />that the revegetation success standards for vegetation cover and herbaceous production be <br />revised to reflect removal of the ineligible species from the final revegetation success <br />criteria. This revision of the success criteria is underway (Technical Revision 43). This <br />monitoring report will represent the results of the monitoring with respect to the <br />revegetation success criteria currently in effect. Data will continue to be presented so as <br />Coors Energy Company Keenesburg Mine Page 5 <br />2012 Revegetation Monitoring Report <br />