2011-09-07_REVISION - C1994082 ‎(2)‎

• Permit No: C1994082
• IBM Index Class Name: REVISION
• Doc Date: 9/7/2011
• Doc Name: Adequacy Review Responses
• From: Seneca Coal Company
• To: DRMS
• Type & Sequence: SL3
• Email Name: SLB
• Email Name: SB1
• Media Type: D
• Archive: No

Area
Total All Hit Cover (x)
s
N
min
t
Phase II Bond Release
Block
58.4
15.87
29
21
1.313
Aspen ERA
159.1
21.1
15
11
1.345
Mountain Brush ERA
117.7
11.1
16
14
1.341
Sagebrush ERA
66.7
10.9
17
15
1.337
Steep Mountain Brush
ERA
43.5
4.96
15
15
1.345
Area
Allowable All Hit
Herbaceous Cover (x)
s
N
n
t
Phase II Bond Release Block
45.02
15.87
29
21
1.313
Aspen ERA
87.3
21.1
15
11
1.345
Mountain Brush ERA
40.6
11.1
16
14
1.341
Sagebrush ERA
35.8
10.9
17
15
1.337
Steep Mountain Brush ERA
17.5
4.96
15
15
1.345
•
•
•
Yoast Mine SL -3
Phase 11 Bond Release Request
February 2011
Table 2. Sample Adequacy Summary for Total All Hit Cover, Phase II Bond Release
Block and Extended Reference Area (ERA), Yoast Mine.
Table 3. Sample Adequacy Summary for Allowable All Hit Herbaceous Cover, Phase II
Bond Release Block and Extended Reference Area (ERA), Yoast Mine.
Sample point locations for the 2010 vegetation sampling used in the Phase II bond release
evaluation study are shown on Maps 1 and 2 of the 2010 Yoast Mine vegetation monitoring
report (February 2011) prepared by ESCO Associates and included in Attachment E.
The revegetation success evaluations determined that the mean allowable all hit herbaceous
cover in the Phase II bond release block was less than the cover standard (described
previously). Since the cover sampling met sample adequacy after a minimum of 15 samples
were collected, statistical testing using a one - sample t -test was made using the following
equation to test the hypothesis of reclamation success for cover (CDRMS 2005 revised rule,
4.15.11 (2)(b)):
t _ Q —
x
Where: x = Bond Release Block Sample Mean
Q = 90% of Standard
s x = Standard error of mean [ S / J ]
S = Sample standard deviation
n = Sample size
4 = Calculated t value
t = Table t value (alpha = 0.1) see Rohlf and Sokal (1969)
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