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2.2 Determination of Ground Cover <br />Ground cover at each sample point was determined utilizing the point-intercept methodology as <br />illustrated on Exhibit 1. As indicated in this figure, Cedar Creek utilizes state-of-the-art instrumentation it <br />has pioneered to facilitate much more rapid and accurate wllection of data. A transect of 10 meters <br />length was extended in the direction of the next sampling location from the flagged center of each <br />systematically located sample point. At each one-meter interval along the transact, a "laser point bar" <br />was situated parallel to, and approximately 4.5 feet vertically above the ground surface. A set of 10 <br />readings was recorded as to hits on vegetation (by species), litter, rock (>2mm), or bare soil. Hits were <br />determined at each meter interval by activating a battery of 10 low-energy specialized lasers` situated <br />along the bar at 10 centimeter intervals and recording the variable intercepted by each of the vertically <br />projected narrow (0.02' focused beams (see Exhibit 1). In this manner, a total of 100 intercepts per <br />transact were recorded resulting in 1 percent cover per intercept. (Second hits on understory vegetation <br />were not collected owing to the managerial nature of collected data.) All reclaimed area vegetation as <br />well as reference area vegetation (including both herbaceous and shrub strata) were subject to sampling. <br />This methodology and instrumentation facilitates the collection of the most unbiased, repeatable, and <br />~ precise ground cover data possible. <br />2.3 Sample Adequacy Determination <br />Sampling of the individual units was restricted to 10 samples (20 for reference areas) for cover due <br />to the managerial nature of collected data. However, for informational purposes, sampling adequacy <br />(nm~„) has been calculated for each variable in each sampling unit in accordance with the Colorado <br />guideline (April 18, 1995) formula for sample adequacy when statistical testing is not required, as <br />follows: <br />nmm = ~r252) ~ (O.l.Y)2 <br />Where: n =the number of actual samples collected with a minimum of SO in each unit; <br />t = the value from the t distribution for 90% confidence with n-1 degrees of freedom; <br />sz ° the variance of the estimate as calculated from the initial samples; <br />z =the mean of the estimate as calculated from the initial samples. <br />""` Lasers utilized for this instrument are state-of-the-art and of specialized design to emit a unique eledro-magnetic <br />wavelength visible under full sunlight, a condition previously not possible with portable low-energy lasers. <br />CEDAR CREEK ASSOCIATES, INC. Page 7 SNOWCAP COAL COMPANY <br />Revegetation Evaluation - 2006 <br />