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I • n =number of primary units actually sampled <br />M =total number of sample elements (secondary units) that exist within each primary unit and are <br />potentially to be sampled <br />m = number of secondary unit elements (2 m X 50 m sample transects) actually sampled within <br />each primary unit <br />Confidence Limits <br />Confidence limits for comparisons to reference area based performance standards and technical <br />standards were calculated using a 1-tailed t-value for alpha error probability of 0.10 at (n-1) <br />degrees of freedom multiplied by the standard error of the mean of the sampled area. <br />C.I. = t, s <br /> Jn <br />• Performance Standards <br />COVER: A cover pertormance standard was calculated in accordance with procedures contained <br />in the Seneca II permit and is based on twice the weighted average of herbaceous cover in the <br />Mountain Brush and Sagebrush reference area. An acreage weighted reference area <br />comparison based on the relative acreage of each pre-disturbance plant community was used. <br />Weighting was based on Mountain Brush Reference area as 83 percent and Sagebrush <br />Reference area as 17 percent of pre-mining vegetation cover. Although quantitative sampling of <br />reclaimed areas was conducted at Seneca II Mine in 2001 for purposes of monitoring and not for <br />the purpose of bond release, a line that demarcates 90 percent of this standard has been placed <br />on Figure i for illustrative purposes. It is presumed that when sampling for bond release does <br />occur and when the parameter mean for a bond release block is at least 90% of the calculated <br />success standard or approved technical standard, then revegetation will be considered <br />successful for that parameter. <br />The calculation of 90 percent of the cover performance standard appropriate for 2001 sampling is <br />demonstrated below. <br />