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New Horizon Mine: 2007 Vegetation Sampling for Phase 2 Bond Release <br />• Comparison of Measured Parameters. The following summarizes CDRMS regulations and <br />guidance on comparing vegetation measurements at reclaimed lands to standards for purposes <br />of determining adequacy for Phase 3 bond release. (rec) =reclaimed area, (ref) =reference <br />area. Minimum sample size of n = 15 is required at each site. <br />1: If mean (rec) equals or exceeds Q, and if sample adequacy exists at (rec) and (ref), then <br />revegetation is successful. If mean (rec) is less than Q, then statistical hypothesis <br />testing is required, as follows. <br />2. If sample adequacy exists at (rec) and (ref), use aone-sample "standard null" t-test. A <br />one-sample test assumes that the reference area mean is a "standard" rather than a <br />sample mean, and does not require an evaluation of the variance of the reference area <br />mean or other statistical complications inherent in two-sample tests. The null hypothesis <br />being tested is that the mean (rec) is equal to or greater than Q. If the null hypothesis is <br />NOT rejected, revegetation is successful. <br />3. If sample adequacy does NOT exist at (rec) but does at (ref), use aone-sample "reverse <br />null" t-test. However, CDRMS requires a minimum of n = 30 at (rec), and that mean (rec) <br />is greater than Q. The reverse-null t-test is one-sided with alpha = 0.20. The null <br />hypothesis being tested is that the mean (rec) is less than or equal to Q. If the null <br />hypothesis is rejected vegetation is successful. <br />4. If sample adequacy does NOT exist at (ref), use atwo-sample "reverse null" t-test with <br />Satterthwaite approximation of standard error and degrees of freedom. The test <br />• requires a minimum of 30 samples in the (rec) and (ref), and that mean (rec) is greater <br />than Q. The reverse-null t-test is one-sided with alpha = 0.20. The null hypothesis being <br />tested is that the mean (rec) is less than or equal to Q. If the null hypothesis is rejected <br />vegetation is successful. <br />2.0 PROCEDURES <br />2.1 Study Areas <br />Areas to be studied were determined by WFC. Study sites are shown on the attached map <br />figures, and included the following areas: <br />1. Irrigated Pasture Reference Area (7.2 acres). This area adjacent to (east of) the New <br />Horizon Mine is owned by WFC and leased to an operator who irrigates the property and <br />grazes horses on the property in winter. The reference area was first established in 2007 <br />and the vegetation has not been studied before. <br />2. Irrigated Pasture Reclaimed, Phase 3 (128.6 acres). This area is in its first year of eligibility <br />for Phase 3 vegetation measurement. WFC is also applying for Phase 2 bond release on <br />this area. <br />3. Irrigated Pasture Reclaimed, Phase 2 (240.0 acres). This area includes the Phase 3 <br />Irrigated Pasture reclaimed lands described above, and additional reclaimed lands eligible <br />• for Phase 2 measurement but not yet eligible for Phase 3 measurement. <br />BIO-Logic Environmental 5 <br />November 12, 2007 <br />