2020-03-31_PERMIT FILE - C1981019A ‎(6)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 3/31/2020
• Doc Name: Volume 1 Rule 4
• Type & Sequence: TR136
• Section_Exhibit Name: 4.01 Through 4.30
• Media Type: D
• Archive: Yes

RULE 4 PERFORMANCE STANDARDS
herbaceous competition, seed mixes were designed so that shrubs contributed the majority of the
seed mix. Two seed mixes were evaluated at each mine:
• a native grass, forb and shrub seed mixture and
• a seed mixture of unpalatable native shrubs and low-competitive native grasses and forbs.
At each mine,one treatment included alternating strips seeded with only the shrub/forb component
of the mix. At Seneca Mine, treatments included seedling transplants, for tall shrub species that
have proven to be particularly difficult to establish from seed.
Typical topsoil replacement depths varying from 12 -20 inches creates an ideal environment for
grass establishment. Therefore,the depth of topsoil on the plots was varied to evaluate shrub and
forb response to topsoil depths ranging from 0 to 20 inches.
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 P Plot 2" Plot 3` 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
Rule 4 Performance Standards 4-52 Revision Date: 1/22/20
Revision No.: TR-136