2016-12-12_PERMIT FILE - C1981019A ‎(2)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 12/12/2016
• Doc Name: Permits
• Section_Exhibit Name: Volume 15 Rule 2
• Media Type: D
• Archive: Yes

RULE 2 PERMITS
Drill Hole C-04-36
Unsuitability range in feet:
SAR > 15 = 19.9 feet
Se>0.3=5.15 feet
B>5.0=0 feet
Sat <25 or >80 = 85.6 feet
Mo > 1.0 = 0 feet
Total Drill Hole Depth = 610.6 feet
Total Percentage of unsuitable material:
SAR = 19.9 feet/610.6 feet = 3.2590894202%
Se = 5.15 feet/610.6 feet = 0.84343268916%
B = N/A
Sat = 85.6 feet/610.6 feet = 14.018997707%
Mo = N/A
No Special Handling Procedures will be required for the overburden in the Collom Area (please see
Section 2.04.6 — Exploration Test Boring Results Summary). It was discussed between the Division of
Reclamation, Mining and Safety (DRMS) and Colowyo that suspect levels of the Sodium Adsorption
Ration (SAR), Selenium (Se), Boron (B), Saturation % (Sat), and Molybdenum (Mo) need to be
addressed in more detail to determine that Special Handling Procedures, that are outside the normal pit
operational procedures, will not be needed in the Collom expansion area. Review of the analysis
spreadsheets in Exhibit 6, Item 9 demonstrate minimal instances of analyses for pH, electrical
conductivity, nitrate as N and Acid -Base potential being outside of the suitable range for the four drill
holes analyzed above.
Based on similarities between overburden suitability analysis results in the Colowyo existing permit area
and the Collom permit expansion area, and on previous discussions between CDRMS and Colowyo,
suspect levels of Sodium Adsorption Ratio (SAR), Selenium (Se), Boron (B), Saturation percent (Sat),
and Molybdenum (Mo) will not need to be addressed in more detail to determine if Special Handling
Procedures, that are outside the normal pit operational procedures, will be needed in the Collom area.
Historically, beginning around 1983, Colowyo initiated overburden monitoring in both the pit
(truck/shovel materials) and on regraded overburden. See CDRMS Permit Exhibit 6, Item 4 as described
in the associated January 4, 1983 Colowyo memo to Dan Mathews, CDRMS, for an overview of this
initial program. Starting in 1990, Colowyo eliminated the in -pit sampling program. Sufficient data had
been collected to indicate that all weathered overburden material (ie within — 50 feet of the ground
surface) was suitable for replacement onto the reclaimed surface prior to topsoil replacement. Three
revisions were submitted to the Division and approved on January 24, 1984, August 17, 1983, April 24,
1990, and PR -02 respectively. The following summarizes the requirements of the current regraded
overburden (backfill) sampling program and supersedes all previous commitments. It is based on the
following limitations of the earlier program.
Placing weathered overburden material onto reclamation areas prior to final regarding, and
Sampling regraded overburden at a density of one composite surface sample per 5 acres of
regraded spoil.
The regrading of overburden is an event that takes place sporadically during the year. Once backfill areas
are regraded, but prior to topsoil replacement, the new locations are identified and sampled. A life -of -
mine sampling grid has been established on 500 -foot centers, and each sample location on the grid
corresponds to a letter/number combination as established on the sampling map. Using this grid interval,
Collom — Rule 2, Page 81 Revision Date: 11/16/16
Revision No.: MR -166