2011-12-22_REVISION - M1982155

• Permit No: M1982155
• IBM Index Class Name: REVISION
• Doc Date: 12/22/2011
• Doc Name: Response to Adequacy Review
• From: Blue Earth
• To: DRMS
• Type & Sequence: AM1
• Email Name: BMK
• Media Type: D
• Archive: No

Aspect
Mining Operation
Disturbed
Area
(acres)
A
Active mining face and highwalls (½H: 1 V) to be cut and filled at
3H:1 V slopes, graded, topsoiled, and seeded; 2,000 ft x 79 ft
4.0
B
Pit bottom to be graded with overburden, topsoiled, and seeded
15.0
C
Stockpile areas to be tilled and seeded
11.5
D
Roads and other miscellaneous disturbances for grading and
seeding
0.5
Total Disturbed Area
31.0
Mr. Berhan Keffelew
. RE: Schmidt Construction Company M- 1982 -155
December 21, 2011
concurrent reclamation will be used (31 disturbed acres). Specifically, 4,000 feet of
exposed highwall and average pit depth of 30 feet in the original submittal verses
2,000 feet of exposed highwall and average pit depth of 25 feet in the revised submittal.
Note: There was an error in the revised application for the reclamation cost per acre
calculation. In Exhibit D, Mining Plan, the disturbed area calculated in the mining
aspects table is 31 acres. However, in Exhibit L, Reclamation Cost, 49 acres is used for
the disturbed area. If the correct disturbed acreage is used (31 acres) in the reclamation
cost estimate, the reclamation cost per acre is $4,691 instead of the reported $2,968.
Adequacy review comments regarding reclamation techniques, reliable quantities of
overburden available for reclamation, and estimated reclamation costs illustrates
reclamation techniques and cost estimates used for the proposed amendment area need to
be more consistent with the existing Fountain Pit operation. This is especially important
if estimated reclamation costs for the amendment area are used to estimate the existing
Fountain Pit operation reclamation bond. Reclamation techniques used at the existing
Fountain Pit and proposed for the amendment area include:
• Concurrent reclamation,
• Average pit depth 25 feet,
• Mining face and highwall — cut and fill slope creation during reclamation,
• Reclaimed slopes at 3H:1 V or flatter (slope length = 79 feet),
• Available overburden used for slope and pit bottom cover (average depth = 1- foot), and
• Topsoil cover at 4 inches or greater, depending upon availability.
Aspects table from Exhibit D, Mining Plan:
The table illustrates a point in time where the mining disturbance could be at its
maximum. With such a relatively small site, it is assumed that the mining disturbance
will be at its greatest if the pit is mostly mined. During this scenario, no reclamation will
have been performed on the active mining face (1,000 feet), approximately 500 feet of
highwall on both sides of the mining face, and about half of the pit bottom.
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