2013-04-19_REPORT - C2009087 ‎(7)‎

• Permit No: C2009087
• IBM Index Class Name: REPORT
• Doc Date: 4/19/2013
• Doc Name: 2012 Testing For revegetation Success for Phase III Bond Release Year One of Two
• From: Peabody Sage Creek Mining, LLC
• To: DRMS
• Permit Index Doc Type: Reveg Monitoring Report
• Email Name: JDM
• Email Name: DIH
• Media Type: D
• Archive: No

Vegetation Parameter
Values
Reverse Null Approach
Mean
N
Lower 80%
conf limit
70 % of
Standard
Pass ?
Yes / No
2012 BRB PSCM -2
Woody Plant
Concentration Area
Density
2068.5
53
1653.9
1400
Yes
Since critical taw = 0.850 (one - tailed, alpha = 0.2, 52 df) is not exceeded by t reclamation success for
concentration area woody plant density for Phase III BRB PSCM -2 in 2012 is NOT demonstrated using
this parametric reverse -null t -test.
Since sample adequacy was not achieved in the Woody Plant Density Concentration Area, and
revegetation success for woody plant density was NOT demonstrated using a reverse -null t -test, an
alternate non - parametric reverse null approach (a Quantile Test, see Gilbert 1987, Conover 1980) was
used, as set forth in CDMG 2005 revised rule, 4.15.11 (3)(a) (Table 2):
1
L = p(n + i) — Z [rap (1 02
Where:
L= order statistic corresponding to the one sided lower 80% confidence limit
p = 0.5 (e.g. the 0.5 quantile, or median)
n = sample size
Z = 0.842 (the t -table value for infinite degrees of freedom for 1 sided test; alpha = 0.20)
Table 2. Reverse Null Approach Based on the Median Evaluating the Woody Plant Density
Concentration Area (see calculations in Table 1 -3)
Since the lower 80% confidence limit is greater than 70% of the shrub concentration standard of 2000
stems per acre (1400), reclamation success for concentration area woody plant density for Phase III in
BRB PSCM -2 2012 is demonstrated.
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