Laserfiche WebLink
Between August 3, 1977 and September 21, 1981, and subject to provisions of Interim (Initial) <br />Program and the similar 1976 Colorado Act (BRB -2), quantitative cover and production data will be <br />used as a basis for discussion, but no formal (statistical) hypothesis testing will necessarily be <br />• undertaken. The coal regulations have required two years of quantitative sampling to demonstrate <br />compliance with success standards, since August 15, 1980. As such, the success criteria for each of <br />Blocks 2, 3, 4 and 5 will be demonstrated for at least two of the last four years of the liability period, <br />in accordance with Rule 4.15.7(5). Block 1 will require only 1 year of sampling to demonstrate <br />compliance. <br />Sample Adequacy Determination <br />After fifteen (15) cover samples in a BRB or reference area, sanple adequacy will be evaluated based on total live foliar <br />cover by vascularplants using the fallowing expression: <br />t <br />n = �dxy <br />where: <br />n = minimum sample size <br />s = Sample variance (n -1 degrees of freedom) <br />d = Precision (0.10 for cover and production; 0.15 for woody plant density) <br />x = Sample arithmetic mean <br />t = The ((X =.10) t -table value for a 1 tail t -test, n -1 degrees of freedom (infinite <br />degrees of freedom may be used if n >30) <br />n = Sample size <br />After at least thirty (30) production samples in BBB -3 or a reference area, sample adequacy will be evaluated initially <br />bared on green weight values (and later based on oven -dry weight values) using the above formula. Adequacy results <br />will ultimately be based on oven -dry weight data. <br />Hypothesis Testing Approaches <br />• For BRB -3, in which formal hypothesis testing will be pursued, the following procedures will be <br />followed: <br />Cover and Production <br />Cover and production data will be used to test the following hypotheses <br />Percent absolute (foliar) first hit herbaceous vegetation cover of BRB -3 > 90% of TWICE the <br />weighted absolute (foliar) first hit herbaceous vegetation cover from the reference areas (weighted <br />based on 83% original extent of Mountain Brush / Aspen and 17% original extent of Sagebrush). <br />The factor of 2x the reference area first hit herbaceous cover of the reference areas is explained in <br />Appendix 13 -15, Historical Approaches to Testing for Successful Reclamation. <br />Total annual herbaceous production of BRB -3 ? 90% of weighted total annual herbaceous <br />production from the reference areas (weighted based on 83% original extent of Mountain Brush / <br />Aspen and 17% original extent of Sagebrush). <br />The Mountain Brush /Aspen and Sagebrush Reference Areas will be sampled for adequacy first to establish the <br />standards for comparison against subsequently collected reclaimed area values. If after 15 cover or 30 production <br />samples have been completed in BBB -3, sample adequacy has been achieved and the reclamation area mean total <br />herbaceous foliar cover and herbaceous production are above 90% of the reference area - derived standard, an affirmative <br />indication of reclamation cover success will be asserted. <br />ESCO Associates 13 -13 -6 TR40 *01/07 <br />• <br />