2019-02-08_PERMIT FILE - C1981019A

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 2/8/2019
• Doc Name: Volume 1 Rule 4
• Section_Exhibit Name: 4.01 Throuugh 4.30
• Media Type: D
• Archive: Yes

RULE 4 PERFORMANCE STANDARDS
Composite soil and overburden samples were taken from each treatment at each mine. Overall,
the soils (topsoil and spoil) at all three -mine sites have good physical and chemical properties.
Soil pH ranges from 6.9 to 7.8, macronutrients appear to be adequate for sustained plant growth,
organic matter contents are relatively high (3.7% to 6.3%), salt levels are low (EC ranges from 0.6
to 1.6 mmhos/cm and SAR ranges from 0.3 to 1.8), cation exchange capacity (CEC) is in a normal
range, and textures are clay loam and sandy clay loam. Overall, topsoil and spoil at all mine sites
have favorable characteristics and provide a suitable plant growth medium.
At Colowyo, soil pH ranges from 7.5 to 7.8, macronutrients appear to be adequate for sustained
plant growth, organic matter contents are relatively high (3.7% to 4.8%), salt levels are low (EC
ranges from 0.6 to 1.2 mmhos/cm and SAR ranges from 0.3 to 1.6), cation exchange capacity
(CEC) is in a normal range, and textures are clay loam and sandy clay loam. The detailed soil and
overburden analysis for the Colowyo Mine is provided below.
Parameter
Plot la
Plot 2b
Plot Y
Plot 4d
Plot 5e
pH
7.5
7.5
7.5
7.7
7.8
% OM
4.1
4
4.8
4.1
3.7
NH4-N mg/kg
4.9
4.6
6
6.1
8.7
NO3-N mg/kg
24.1
19.1
22.3
13.7
18.1
P mg/kg
15
9.6
12
7.8
29
K mg/kg
191
210
201
95.1
105
Ca meq/L
4.9
4.1
4.4
3.5
5.5
Mg meq/L
2.6
1.6
2
2.4
4.1
Na meq/L
0.8
0.6
1.3
1.9
3.5
K meq/L
0.2
0.5
0.4
0.2
0.2
EC mmhos/cm
0.7
0.6
0.7
0.7
1.2
SAR
0.4
0.3
0.8
1.1
1.6
CEC meq/100g
26.8
22.1
22.9
27
23.3
% Sand
41
51
48
39
41
% Silt
23
23
23
23
25
% Clay
36
26
29
35
35
Texture
clay loam
sandy clay loam sandy clay loam
clay loam
clay loam
aPlot 1 = 18 inches of topsoil, strip seeding in alternate rows.
bPlot 2 = 6 inches
of topsoil
and surface
manipulation, seeded
with native
shrubs and low
competitive forbs.
°Plot 3 = 6 inches of topsoil, strip
seeding in
alternate rows.
dPlot 4 = Non-topsoiled spoil, strip
seeding in alternate rows.
ePlot 5 = Non-topsoiled spoil, seeded with unpalatable native shrubs and low competitive forbs
and grasses.
To evaluate the impact from wildlife browsing, elk proof fencing was constructed on one-half of
each treatment.
Colowyo Mine Specific Field Trial
Rule 4 Performance Standards 4-52 Revision Date: 11/27/18
Revision No.: TR -129