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Mine Area No. 3 <br />In 2010 the mean total percent cover was found to be 32.40 %, total perennial cover was found to be <br />22.6 %. In 2011, the mean total percent cover was found to be 35.72 %; total perennial cover was found <br />to be 26.56 %. For this area, a comparison was made to a weighted average of the mean total perennial <br />cover found within Sagebrush Reference Area A and Sagebrush Reference Area B. The success <br />standard was 18.78% and 18.48% mean total perennial cover in 2010 and 2011 respectively. By direct <br />comparison, Mine Area No. 3 exceeded the success standard. The dominant grass species found in 2010 <br />was Needle and Thread, Blue Grama and Indian Ricegrass. The dominant forb found at the site was <br />Scarlet Globemallow and Russian thistle. In 2011 the dominant grass species found at the site were Blue <br />Grama, Indian Ricegrass and Needle and Thread. The dominant forb found at the site was Scarlet <br />Globemallow and Russian thistle. Annuals and noxious weeds did not count toward revegetation <br />success for cover. Although some portions of the reclamation still retain a higher percentage of annuals <br />than is often seen in a permanent stand eight years or older, removing that portion of the cover value <br />attributed to annual and biennial species, the reclaimed area still exceeds the weighted reference area <br />standard. <br />In 2010, six perennial species met the required relative cover percentages set for the species diversity <br />success standard. The warm season perennial grasses that met the criteria were Blue Grama and James <br />Galleta (Hilaria jamesii). The cool season perennial grasses were Indian Ricegrass, Bottlebrush <br />Squirreltail and Needle and Thread. The perennial forb was Scarlet Globemallow. The species diversity <br />success standard was met for Mine Area No. 3 in 2010. In 2011, six perennial species met the required <br />relative cover percentages set for the species diversity success standard. The warm season perennial <br />grasses that met the criteria were Blue Grama and James Galleta. The cool season perennial grasses <br />were Indian Ricegrass, Bottlebrush Squirreltail and Needle and Thread. The perennial forb was Scarlet <br />Globemallow. The species diversity success standard was met for Mine Area No. 3 in 2011. <br />Production was significantly higher in Mine Area No. 3 than the reference areas. In 2010 average <br />perennial production was found to be 204.5 lbs /acre. The weighted success standard for this mine area <br />was found to be 85.75 lbs /acre. In 2011, the average perennial production was found to be 235.7 <br />lbs /acre. The weighted success standard was found to be 142.6 lbs /acre. The sample size was adequate <br />and by direct comparison, Mine Area No. 3 exceeded the success criteria for production. <br />In conclusion, both Mine Area No. l and No. 3 have met or exceeded the revegetation success standards <br />for vegetation cover, production and species diversity. <br />Protection of the Hydrolo2ic Balance <br />Rule 3.03.2(2) requires the Division to evaluate hydrologic impacts prior to releasing reclamation <br />liability. This evaluation must consider whether pollution of surface or subsurface water is occurring <br />and the probability of future occurrence of such pollution. The Division's evaluation is summarized <br />below. <br />Based on review of monitoring records, annual hydrologic reports, and supplemental water quality <br />data provided by the operator at the Division's request, the Division finds that the Hamilton Mine has <br />Page 12 of 16 <br />