Laserfiche WebLink
Seneca 11 Mine June 2011 <br />SL-5 Phase 11 Bond Release Request <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 (32.2% 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. The hypothesis of reclamation success was tested using a parametric test of the <br />"reverse null" hypothesis. This was conducted using the following expression (CDRMS 2005 <br />revised rule, 4.15.11 (2)(c)): <br />z-Q <br />tc _ <br />S- <br />x <br />Where: Y = Bond Release Block Sample Mean <br />Q = 90% of Standard <br />S_ = Standard error of mean [ s l -NFn ] <br />x <br />S = Sample standard deviation <br />n = Sample size <br />t,: = Calculated t value <br />tr = Table t value (alpha = 0.2) see Rohlf and Sokal 1969 <br />If t, is greater than the 1-tailed t table value for alpha error probability of .20, with (n-1) degrees <br />of freedom then Ho is rejected, and revegetation was deemed successful. <br />A one-sample t-test of the assertion that the 2010 Phase II BRB allowable cover is <br />indistinguishable from 90% of the standard is as follows: <br />tc = (40.0 - 32.2) /(9.39 / sgrt 21) = 3.76 <br />Since critical t = 0.860 (one-tailed, alpha = 0.2, 20 df and t, is greater than this critical value, the <br />"reverse null hypothesis" is rejected and reclamation success for Phase II is demonstrated. <br />10