2019-01-17_PERMIT FILE - C1981008A ‎(2)‎

• Permit No: C1981008A
• IBM Index Class Name: Permit File
• Doc Date: 1/17/2019
• Doc Name: Revegetation
• Section_Exhibit Name: Section 2.05.4‎(2)‎‎(e)‎ Revegetation
• Media Type: D
• Archive: Yes

Table 2.05.4(2)(e)-1 Irrigated Pasture Reference Area Weighted Production Factor
Soil Type
Area Acres
% of Total
Assi ned Factor
Wei hted
15
2.4
35.24
1.20
0.423
81
1.4
20.56
1.00
0.206
10
1.35
19.82
1.00
0.198
77
1.66
24.38
0.80
0.195
Total
6.81
100.00
1.022
As can be seen from Table 2.05.4(2)(e)-1, the weighted average factor for the reference area is
1.022. Map 2.05.4(2)(e)-1 & 2 shows the NRCS soil types for the entire mine permit area. If an
area of Irrigated Pasture is submitted for bond release, the weighted average factor of this area
is calculated based on the areas of each soil type multiplied by the associated factor. These
numbers are added and divided by the total area to get the weighted average factor. This
weighted average factor is then divided by the reference area weighted average production
factor (1.022), and the resulting value is multiplied by the reference area production sample
mean to obtain the adjusted reference area sample mean. The production standard for that
particular reclaimed block is 90% of the adjusted reference area sample mean. For the purpose
of statistical comparisons, the reference area production sample standard deviation must be
multiplied by the same value as the sample mean.
This method has the advantage of truly accounting for the differences in soil type from one area
to another. This may not be necessary in other smaller tracts of Irrigated Pasture at other mines,
but it is important at the New Horizon Mine, since there is substantial variation of soil types.
NRCS-Montrose informed New Horizon that a few of the soil types are poor enough that they
are simply not irrigated anywhere else in Montrose County. Others, especially some in the
western part of the mine area, are better than those in the reference area.
For cover success standards, the cover in the reference area will be compared to the cover in the
reclaimed area with no weighted average adjustments for soil type.
Map 2.05.4(2)(e) - 2 shows the location of the Irrigated Pasture reference area and Attachment
2.05.4(2)(e) - 5 shows the Statistical Data of the 2007 Sampling of the Irrigated Pasture Reference
Area. Cover and Production data are included.
For Irrigated Pasture areas, vegetation cover and herbaceous production will be measured at
reclaimed sites and the reference area. Comparisons of the mean parameter values between the
reclaimed areas and the reference area will be used to determine revegetation success, as
described below. As described above in this section, the production standard is adjusted for soil
types in the reclaimed area vs. the reference area.
Page 17 October 2016 (TR -75)