2019-01-09_PERMIT FILE - M2019001 (3)

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EXHIBIT L Reclamation Costs In order to calculate maximum potential reclamation liability to the State, we have selected a point in time where reclamation costs could be at a maximum. It is assumed that the time of maximum mining disturbance will be almost midway through mining activities. During this scenario, no reclamation will have been performed on the active mining face nor the near vertical side slopes on both sides of the mining face. Reclamation of the pit in the southern portion of the site will be about half way complete. This portion of the pit will need to be backfilled and graded to let stormwater flow freely through the reclaimed site. During mining, backfilling of the pit will progress in one area such that final grade will be achieved and the backfilled area can be topsoiled and revegetated prior to beginning backfilling in another area. However, in the maximum potential reclamation liability scenario, approximately half of the pit area (30.5 acres) will require additional backfill, grading, topsoiling, and seeding to create a final pit floor grade that will drain stormwater freely. The active mining area will include the active mining face, un-reclaimed pit side slopes, and un-reclaimed active mining area pit floor. This active mining area will be separate from the pit in the southern portion of the site described above. The active mining face will be near vertical with a maximum length of 1,000 feet and an average height of 10 feet. In front of the active mining face, an area 100 feet wide will have been pre-stripped in anticipation of mining (2.3 acres). In addition, a maximum 500 feet of un-reclaimed pit side slopes may be adjacent to each end of the active mine face. These side slopes will also be near vertical with an average height of 10 feet. Framed by the active mining face and pit side slopes, the pit floor (11.5 acres) will be un-reclaimed, contain overburden, raw material, and product stockpiles and, when needed, the portable processing facility and asphalt plant may be located here. During normal reclamation, the mining face and active pit side slopes would be backfilled to a minimum 3H:1 V slope. However, if mining stops at this maximum potential reclamation liability point, the mine face and pit side slopes will not be adjacent to the permit boundary and the highwalls can more efficiently be dozed to the required 3H:1V or flatter slope. Following dozing, the areas will be rough graded in preparation for topsoil/overburden growth medium placement, final grading, and seeding for revegetation. The active mining pit floor will receive only enough topsoil/overburden backfill to establish a growth medium for revegetation. In addition to the active mining area, parts of the mine pit in the southern portion of the site will need to be backfilled, graded, topsoiled, and revegetated. To generate the material necessary to complete backfilling of the pit so that it will drain freely, additional material will need to be harvested from the un-mined portion of the site. Topsoil/overburden material will first be stripped from the material harvest area (78 acres) and stockpiled. Then the underlying overburden will be removed and used to finish backfilling the pit. Finally, the topsoil/overburden material will be replaced over the material harvest area to establish a growth medium for revegetation. Miscellaneous disturbed areas at the point of maximum potential reclamation liability will include the scale house area, internal haul roads, and the main site access road. These areas will Lazy Two Pit DBMS 112 Permit Application Page 23