2015-04-08_REVISION - C2009087

• Permit No: C2009087
• IBM Index Class Name: Revision
• Doc Date: 4/8/2015
• Doc Name: Adequacy Question Response
• From: Peabody Sage Creek Mining, LLC
• To: DRMS
• Type & Sequence: SL3
• Email Name: JDM
• Email Name: DIH
• Media Type: D
• Archive: No

Peabody Sage Creek Mine July 2014
SL -3 Phase III Bond Release Request
Table 3. 2010 and 2011 Data and Sample Adequacy Summary for Allowable First Hit
Herbaceous Cover, Phase III BRB PSCM -1 and Sagebrush and Mountain Brush
Reference Areas.
Represents the ratio adjusted all hit cover values from the mountain brush RA.
2 The value in parenthesis represents allowable all hit sample adequacy. See ratio discussion.
The allowable herbaceous cover was derived from an adequate sample of all hit data from the
mountain brush reference area and then converted back to a first hit basis using the ratio of first
hit:all hit cover to arrive at the 12.8 and 21.0 allowable first hit cover values. The ratio
information was also used to address sample adequacy. Refer to page 6; Appendix G, tables G -2
and G -5 and Appendix I in the vegetation report in Attachment D.
The cover success standard for PSCM reclaimed lands is an area - weighted average of allowable
first hit herbaceous cover values determined from the mountain brush and sagebrush reference
areas. CDRMS requires sample adequacy to be assessed using first hit herbaceous cover data. In
the mountain brush, achieving sample adequacy using first hit herbaceous cover data results in
very high sample numbers as a result of high variability. The mountain brush structure is
dominated by a rather dense woody canopy, but may also have some areas of relatively open
canopy to the herbaceous understory. These characteristics contribute to the highly variable first
hit herbaceous cover data. Obviously, all hit herbaceous cover data (i.e., multiple hits combined)
E
Allowable First Hit
Area
s
N
NI,,;,,
t
Herbaceous Cover (x)
Phase III Bond Release
54.9
12.0
30
9
1.311
BRB PSCM -1 2010
Mountain Brush RA 2010
12.81
5.1
15
29(7)2
1.345
Sagebrush RA 2010
44.7
8.8
15
8
1.345
Phase III Bond Release
55.8
8.9
30
5
1.311
BRB PSCM -1 2011
Mountain Brush RA 2011
20.951
9.2
21
34(18)2
1.325
Sagebrush RA 2011
44.4
7.2
15
5
1.345
Represents the ratio adjusted all hit cover values from the mountain brush RA.
2 The value in parenthesis represents allowable all hit sample adequacy. See ratio discussion.
The allowable herbaceous cover was derived from an adequate sample of all hit data from the
mountain brush reference area and then converted back to a first hit basis using the ratio of first
hit:all hit cover to arrive at the 12.8 and 21.0 allowable first hit cover values. The ratio
information was also used to address sample adequacy. Refer to page 6; Appendix G, tables G -2
and G -5 and Appendix I in the vegetation report in Attachment D.
The cover success standard for PSCM reclaimed lands is an area - weighted average of allowable
first hit herbaceous cover values determined from the mountain brush and sagebrush reference
areas. CDRMS requires sample adequacy to be assessed using first hit herbaceous cover data. In
the mountain brush, achieving sample adequacy using first hit herbaceous cover data results in
very high sample numbers as a result of high variability. The mountain brush structure is
dominated by a rather dense woody canopy, but may also have some areas of relatively open
canopy to the herbaceous understory. These characteristics contribute to the highly variable first
hit herbaceous cover data. Obviously, all hit herbaceous cover data (i.e., multiple hits combined)
E