2019-12-30_REVISION - M2019054 (44)

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Exhibit J Skull Creek Sand Project Mining & Backfill Sequence Prior to mining, all recoverable soils within the affected area will first be salvaged (between 2"- 6") and stored in windrow stockpiles surrounding the various operational areas as depicted on Map D-3. Mining will then commence by excavation of the exposed Dakota outcrop within Pit E-1. Once the outcrop has been removed, alternating blocks of overburden and Dakota Sandstone will be excavated until the pit bottom is reached. Access to the pit bottom will be accomplished by temporary ramps built into the progressing pit highwall to the west. Overburden spoil from Pit E-1 will be hauled out of the pit and placed on the SPRS for eventual rehandle and backfill into the final pit void of Pit E-5. Following the completion of Pit E-1, concurrent in-pit backfill will be utilized to avoid ex-pit haulage and to expedite reclamation. Once concurrent backfill has begun, each successive pit will be mined from East to West in the same manner with the overburden being placed in the previously mined pits up to the designed final reclamation topography (See Exhibit E). When mining of Pit E-5 is complete, the SPRS will be fully re-excavated and hauled back to the pit for final reclamation. Map D-1 also depicts the approximate timing and production for full excavation of pits E-1 to E- 5. This timing assumes a first year at half capacity and a second year at full production. Product Streams Aside from the Dakota Sandstone, all other materials will be considered waste and placed in backfill for reclamation. Surface Water There are not any surface water diversions or impoundments anticipated on the project site. Explosives The use of explosives onsite for mining or reclamation activities is not anticipated. However, if explosives are needed, UMC will first complete and geodetic survey and generate an amendment with DRMS prior to any blasting. 7 12/23/19