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• Both the reclamation and reference areas were gridded and numbered. Grid cell size was 100 <br />feet X 100 feet. These grid cells were placed contiguously by hand on maps of 1:4,800 scale. <br />Sample locations were selected from the numbered grid cells. The SCC-assigned numbers of <br />samples for a given parameter in a given area reFlected previously experienced sample variability <br />or the level of precision required in a given area. Random numbers from a table were used to <br />select grid cells, in the middle of which a sample point was placed, and recorded on the field <br />maps. These sample points were located as accurately as possible in the field using aerial and <br />topographic maps and pacing from known locations. Cover and woody plant density transects <br />were located and oriented using a blind throw of a meter stick. Final location of each herbaceous <br />production quadrat was accomplished with a blind throw of the sampling hoop made from the <br />origin of the associated cover/woody plant density transect. At each cover/woody plant density <br />sampling location, the slope (percent) and aspect of the site (in degrees not corrected for <br />magnetic declination) were determined and recorded, as was the orientation of the transect (in <br />degrees not corrected for magnetic declination). <br />Sample Adequacy Calculations <br />Sample adequacy calculations parameter estimation without hypothesis testing were carried out <br />using the formula as prescribed by the Colorado Mined Land Reclamation Board for parameter <br />estimation without hypothesis testing (CMLRB 1995): <br />tz sz <br />Nmin= ----_----- <br />~d X ~2 <br />where: <br />• t° =one-tailed t-value with (n-1) degrees of freedom, a=0.10 <br />s2 =sample variance <br />d = 0.1 (level of precision or desired detectable reduction) <br />x =sample mean <br />Confidence Limits <br />Confidence limits for comparisons to reference area and technical standards were calculated <br />using a 1-tailed t-value for alpha error probability of 0.10 at (n-1) degrees of freedom multiplied <br />by the standard error of the mean of the sampled area. <br />C.I. = t, s <br />~In <br />Performance Standards <br />COVER: A cover performance standard was calculated in accordance with procedures contained <br />in the Yoast permit document. The all hit herbaceous cover in the Sagebrush Reference Area <br />sampled was 30.8 percent. This was corrected to 30.7 percent for stratification differences, as <br />per permit-specified procedure. Although quantitative sampling of reclaimed areas was <br />conducted at Yoast Mine in 1999 for. purposes of monitoring and not for the purpose of bond <br />• release, a line that demarcates 90 percent of this standard (30.7 x 0.9 = 27.6%) has been placed <br />on Figure 1 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 />