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PROPOSED DECISION - Canadian Strip/Phase II Bond Release <br />October 1, 1990 <br />Page 5 <br />In summary, since modeling shows that post-mining sediment generation is <br />less than in the Dre-mining situation and since the field observations <br />document that erosion at the site would not be disruptive to the <br />Dost-mining land use, the Division finds that both the '79-'81 reclaim <br />and the 1987 reclaim at Canadian Strip are eligible for Phase II Bond <br />Release. <br />The second condition which must be met for Phase II Bond Release regards <br />the successful establishment of vegetation, per Rule 3.03.1(2)(b). The <br />Division considers that the vegetative cover standard must be met, as <br />this parameter relates directly to erosional stability of a site. <br />Wyoming Fuel Company utilizes a reference area in establishing their <br />vegetation standards. Rule 4.15.7(2)(c) states that sampling should be <br />valid at the 90% confidence level with a 0.10 alpha probability on a <br />one-sided error test. <br />Sampling was performed by both the Division and Wyoming Fuel in 1989 and <br />1990. The Division did not sample the reference area in 1989 and was <br />unable to verify the results submitted by the operator as part of the <br />Bond Release request on March 1, 1990. The Division's 1990 evaluation <br />confirmed the Wyoming Fuel data from 1989 as shown by the information <br />found in Table 5; the areas reclaimed between T979 and 1981 do meet the <br />vegetative cover standard, while the area reclaimed in 1987 does not. <br />TABLE 5: Comparison of Cover Sampling Data <br />CMLRD WYOMING FUEL <br />Date of Percent Date of Percent <br />Sampling Cover Sampling Cover <br />T989 <br />'79-'81 8/21/89 27.3% 9/22/89 68.4% <br />'87 8/2l/89 32% 9/22/89 60% <br />Reference N.D. N.D. 9/22/89 69.8% <br />1990 <br />'79-'81 8/7-8/90 48% 8/6-8/90 44% <br />'87 8/7-8/90 40% 8/6-8/90 44% <br />Reference 8/7-8/90 50.2% 8/6-7/90 57% <br />Species diversity evaluations were derived from the data recorded as part <br />of the cover analysis. The species diversity standard found in the <br />permit application states that standard would be met when there are six <br />principal species of which three will be cool season grasses, two will be <br />shrubs and one will be a forb. Cool season grasses will contribute 7% to <br />