2018-09-04_REVISION - C1980007 (11)

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57 XV. Subsidence Control 1. MCC has proposed a subsidence control plan in accordance with Rule 2.05.6(6) and has committed to adopting measures for reducing the likelihood of subsidence, preventing material damage, and mitigating the effects of subsidence. The Division proposes to approve the plan (4.20.1(2) and 4.20.3(1)). a. Inventory of Structures and Renewable Resource Lands Rule 2.05.6(6)(b) requires the operator to include in the permit application an inventory of structures and renewable resource lands in and adjacent to areas proposed for underground mining activities. MCC has previously provided such inventories prior to mining in an area. The inventories are in Section Rule 2.05.6(6) of the PAP. Structures identified in inventories prior to PR-10 are: the segment of State Highway 133 next to panels 18, 18A, and 19 of the mine; Forest Service roads, ditches, trails and stock ponds; and all of MCC’s mine facilities. The renewable resource lands identified in inventories prior to PR-10 inventory are water-bearing bedrock and alluvial strata in and adjacent to mining areas. Structures identified in the PR-10 inventory are: Monument Dam, Minnesota Reservoir, Cow Camp on the Dry Fork (consisting of a wood-framed building on a concrete slab, a smaller wood-framed building, and a livestock enclosure), Forest Service roads, ditches, trails and stock ponds, and MCC’s hydrologic monitoring stations. The renewable resource lands identified in the PR-10 inventory are the water-bearing bedrock and alluvial strata in and adjacent to the South of Divide area. Structures identified in the PR-12 (Dry Fork lease) inventory are: U.S. Forest Service Roads 711 and 711.5, the Deep Creek Ditch, the Minnesota Creek Ditch Rider's cabin, trails, stock ponds, and MCC's hydrologic monitoring stations. The renewable resource lands identified in the PR-12 inventory are the water-bearing bedrock units in and adjacent to the Dry Fork lease area. A thorough subsidence evaluation was completed for the Sunset Trails expansion (PR-15), which can be found in Exhibit 60e of the PAP. No new structures or renewable resource lands were added to the inventory. b. Possible Subsidence Consequences and Mitigation of Impacts Possible subsidence consequences are described in Section 2.05.6(6)(b)(I) of the permit application. Additional information is contained in a report in Exhibit 55, titled “Subsidence Evaluation for the West Elk Mine". Information for specific areas in the permit area can be found in Exhibit 60.