Laserfiche WebLink
Vegetation Type <br />Allowable Herbaceous <br />Cover on a first -hit basis 1 <br />% of Pre - mining Area <br />Mountain Brush <br />15.1 <br />83.0 <br />Sagebrush <br />44.7 <br />17.0 <br />Seneca II Mine <br />SL -5 Phase II Bond Release Request <br />2010 Sagebrush Reference Area First -hit Allowable herbaceous cover 44.7 x 2 = 89.5% <br />90 percent of the Cover Standard = 0.90 [0.83 X (30.2) + 0.17 X (89.5)] = 36.2% <br />tc = (40.0— 36.2) /(9.39 / sqrt 21) = 1.85 <br />10 <br />June 2011 <br />' Herbaceous cover adjusted by subtracting noxious weeds and annual /biennial plant cover in <br />excess of 10% of the remainder. <br />2 Highest possible value with 90% confidence as explained above and detailed in Attachment <br />E. <br />2010 Mountain Brush Reference Area First -hit Allowable herbaceous cover 15.1 x 2 = 30.2% <br />The 2010 Phase II bond release block (BRB) sampling at thirty random locations resulted in <br />cover data that exceeded 90% of the standard (36.2% allowable cover). The figure for allowable <br />cover in the 2010 Phase II bond release block (BRB) (40.0 %) is the result of subtracting tree, <br />shrub and non - herbaceous cover (1.5 %), perennial noxious weed cover (0.95 %) and "excess <br />annual /biennial cover" (2.0 %) from the observed first hit total vegetation cover of 44.4 %. <br />The cover value for the Phase II bond release block (BRB) was greater than the cover success <br />standard. <br />A t -test of the (reverse) null hypothesis that the 2010 Phase II BRB allowable cover does not <br />exceed 90% of the standard (i.e. is indistinguishable from it) was conducted using the expression <br />from CDRMS 2005 revised rule, 4.15.11 (2) (b)) as follows: <br />Since critical t = 0.860 (one - tailed, alpha = 0.2, 20 df) and tc is greater than this critical value, the <br />null hypothesis (that the mean is indistinguishable from the standard) is rejected, and the <br />alternative hypothesis that the reclaimed area mean is indeed larger than the standard is accepted <br />and reclamation success for Phase II bond release is demonstrated. <br />