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All production samples were returned to the lab for drying and weighing. Drying occurred at 105° C <br />until a stable weight was achieved (24 hours). Samples were then weighed to the nearest 0.1 gram. <br />Total weights for each sample site were compiled and converted to pounds per acre prior to success <br />determination. <br />2.4 Determination of Woody Plant Density <br />Belt transects were co- located with the ground cover transects to obtain a reasonable estimate of <br />the woody plant density of the mine site. At each of the sample sites, a 2 -meter wide by 50 meter or 4 <br />meter by 25 meter long belt transect (depending on the distance to the next sample point) was <br />established in the direction of the next sampling point (typically in a cardinal compass direction). Then <br />within each belt, all woody plants (shrubs, trees, sub - shrubs, and succulents) were enumerated by <br />species. Determination of whether or not a plant could be counted was dependent upon the location of <br />its main stem or root collar where it exited the ground surface with regard to belt limits. As with ground <br />cover transects, if the edge of a unit was reached before a belt was complete, it was deflected 90° in the <br />appropriate direction to facilitate completion. <br />2.5 Sample Adequacy Determination <br />Sampling within each revegetation unit was evaluated with 97 or 125 samples (20 or 30 for <br />reference areas) for cover, production, and woody plant density as described in Section 1.1. For bond <br />release applications, the typical procedure is that sampling must continue until an adequate sample, nmin, <br />has been collected in accordance with the Cochran formula (below) for determining sample adequacy, <br />whereby the population is estimated to within 10% of the true mean (p) with 90% confidence. If <br />adequacy is attained, direct mathematical comparisons are allowed in Colorado. If adequacy is not <br />attained, a "reverse- null" "t- test" of the means would be required (assuming a minimum sampling effort). <br />When the inequality (nmin <_ n) is true, sampling is deemed adequate; and n min is determined as <br />follows: <br />nmin = (t / (O.1x) <br />Where: n = the number of actual samples collected; <br />t = the value from the one - tailed t distribution for 90% confidence with n -1 degrees of <br />freedom; <br />S 2 = the variance of the estimate as calculated from the initial samples; <br />R = the mean of the estimate as calculated from the initial samples. <br />Cedar Creek Associates, Inc. 12 Snowcap Mine - 2011 <br />Phase III Bond Release Evaluation - Year 1 <br />