2020-08-10_PERMIT FILE - M1984041

• Permit No: M1984041
• IBM Index Class Name: PERMIT FILE
• Doc Date: 8/10/2020
• Doc Name: Adequacy Review - Preliminary
• From: American Gypsum
• To: DRMS
• Email Name: SJM
• Media Type: D
• Archive: No

in e manner appropriate to water conditions encountered during drilling. Potential
drilling areas are identified On Drawing OO; and
Develop the new East Pit, including removing an average overburden depth of 20 feet.
The East Pit would be excavated toon anticipated pit floor elevation Of0ROO feet amno|
as shown on Drawings 08 and 09. Additional drilling may be required to further explore
the gypsum depth (potential drilling areas shown on Drawing OD). Drilling permits
(including drill hole Plugging and reclamation) would be obtained prior to drilling and
drill holes would be plugged in a manner appropriate to water conditions encountered
during drilling.
Material hauling:
Haul gypsum to American Gypsum's wallboard plant or existing on-site stockpiles;
Haul overburden and intnaUurden to new road construction areau, on-site otonage, or to
inactive pit areas for progressive reclamation; and
Haul iOtnabundeO to in-pit storage areas (inactive 3r88S of the pits) and maintaining
stockpiles.
Progressive(or concurrent)reclamation (Drawings O6 andO8):
BmcKfi|| inactive pit areas with overburden and intnabumdento 2.5H:1Vover8i| o|Opee
where possible.
Final reclamation (Drawings 11 throuQh13`:
Regnadeany areas within the Upper Pit, East Pit. or 8CC88S roads associated with the
proposed disturbance area (listed above)to 2.5H�W slopes or flatter, achieving 3H:1V
vvhena possible;
Remove Culverts and associated hpnap collars/aprons through road or000inga, including
excavating road fill to pre-construction topography to expose culverts, re-establishing
natural drainages at pre-construction grades, and regrading remaining road fill to
2.5H:1Voroha||ovvec
.
Install riprap or other erosion protection measures where necessary (such as re-
established native drainage ch@nne|s); and
RevegetatediSturbed areas.
Drawing 04 shows types and locations of disturbance associated with the proposed Modification.
2.3 Period of Operation
Mining in the Upper Pit is ongoing: based on current mining rates (approximately 500.000tpy)'
mining in the Upper Pit can continue to support American Gypsum's wallboard plant needs for an
additional 15 to 25 years (depending on the quality of gypsum encountered). For the East Pit,
clearing and grubbing/overburden namoove| is anticipated to begin in 2021. The East Pit is
expected to Support mining activities for an additional 26 years (duration may vary depending on
the quality[f gypsum enCountered).
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