2025-08-01_PERMIT FILE - C1981019

• Permit No: C1981019
• IBM Index Class Name: Permit File
• Doc Date: 8/1/2025
• Section_Exhibit Name: Rule 2 Permits -ST
• Media Type: D
• Archive: No

RULE 2 PERMITS

South Taylor – Rule 2, Page 29 Revision Date: 7/21/25
Revision No.: MR-267

Detailed soils information was collected to determine the spatial distribution, suitability, salvage depths
and volume of soils available within the disturbed area associated with the South Taylor mining area. In
addition, the mass balance in salvageable soil materials were calculated to assure an adequate supply of
suitable soil would be available for reclamation of the surface disturbance associated with the South
Taylor mining area. An overall mass topsoil balance is presented in Volume 1, Table 2.05-1.

A previous soils inventory which encompassed the majority of the disturbed area associated with the
South Taylor mining area was performed by Consolidation Coal Company (CCC, 1984). The CCC soil
inventory report includes soil series and map unit descriptions, soil map unit boundary delineations,
physicochemical properties, and recommended soil salvage depths within the South Taylor mining area,
with the exception of the southern portions of T3N, R93W Section 16 and 17. A copy of the Soil
Inventory Danforth Hills Project Rio Blanco & Moffat Counties is included in Volume 13, Exhibit 9, Item
7. Soils information presented in the existing permit document were used for the portions of T3N, R93W
Section 16 and 17 that were not included in the CCC report.

The soils were mapped according to the standards of the National Cooperative Soil Surveys. Soil series
were described and sampled in locations that were typical of the series. Soil sample collection was based
on profile characteristics such as texture, horizon arrangement and depth, coarse fragment, and other
diagnostic characteristics. Sample locations are shown on Map 5B.

Soil samples were analyzed for the following parameters:

• pH;
• Electrical Conductivity;
• Saturation percentage;
• Sodium Adsorption Ratio (SAR);
• Boron;
• Selenium;
• Particle size (texture);
• Coarse Fragments (in the field)
• Organic Matter; and
• Soluble Ca, Mg, and Na.

The soil laboratory and field data were compared with the topsoil and substitute topsoil suitability criteria
shown on Table 2.04.9-5, Soil and Soil Substitute Suitability Criteria, to determine the suitability of each
horizon and map unit. These suitability criteria were developed based on a review of Wyoming
Department of Environmental Quality (1996) and Montana Department of State Lands (1983) topsoil and
overburden suitability guidelines in conjunction with operational and sound reclamation practices for
mined land reclamation.

The soils data representing the soil series were compared to the suitability criteria provided on Table
2.04.9-5. Based on these comparisons, soil horizons that exceeded the criteria provided on the table were
identified and were considered unsuitable as a plant growth medium for reclamation. The salvage depth
for each series was from the surface to the top of the first unsuitable horizon.

Fourteen map units were identified within the disturbed area associated with the South Taylor mining
area. A summary of the limitations and estimated depth of suitable soil is provided in Table 2.04.9-6,
Summary of Soil Limitations and Salvage Depths – South Taylor Mine Area. Soil physicochemical data
from the 18 CCC soil profiles are provided in Table 2.04.9-8 for a total of 60 soil samples. Descriptions