2013-10-17_PERMIT FILE - C1982056A (4)

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Mining District. When the outcrop was perpendicular to the face, cracking of the outcrop occurred with no spalling. When the outcrop was parallel to the panel then cracking and spalling of the outcrop occurred. Based upon the above factors Twentymile does not anticipate any rock fragments entering Middle Creek. The limited amount of outcrop and the panel orientation will minimize spalling of the outcrop. NORTHERN MINING DISTRICT (PR 99 -05) Additionally, mining will continue to the north; this will result in subsiding Fish Creek and its alluvial valley floor, two man -made impoundments, feeder ditch, Twentymile Sandstone, Routt County Road 33, and the Union Pacific Railroad Track. -Each will be discussed below. Land Use Pastureland and rangeland are the predominant land uses in the Northern Mining District. Historically, some of the areas, i.e. part of Section 21, have been identified as cropland. Recently, however, the decision was made to return it to pastureland as it is the more appropriate use for these lands. The land use patterns are presented in Map 3, Premining Land Use. The reason for returning these areas to pastureland is that the previous landowners had broken out pastureland and rangeland and planted grain crops. This was done typically in response to governmental programs. Presently a federal program exists which compensates landowners returning these marginal cropland areas to grasslands. TCC is not involved with this program but has acquired lands, which were enrolled in the CRP program. TCC has elected to keep these areas in grass or plant them back to pastureland. The current land uses in the surrounding area also demonstrate that previously marginal croplands have been returned to grasslands. Therefore, it is TCC's opinion that pastureland was and is the appropriate use for these lands in and around its affected areas. Existing Structures Aquifers The Twentymile Sandstone outcrops along sections of the Foidel and Middle Creek drainages. The Twentymile Sandstone is a large regional aquifer located throughout northwest Colorado. There are no known water supply wells completed in the Twentymile Sandstone in the vicinity of the mine. County Road 33 TCC plans to subside Routt County Road 33, which is a two -lane asphalt road; refer to Map 23B, Structures and Renewable Resources, for location when longwall mining commences in Panel 12 Right within the proposed five - year permit term (1998- 2003). Twentymile has undermined and subsided Routt County Road 33 where it overlies panel 9, 8, 7, and 6 Right. TCC monitored the road while mining and subsidence were occurring and cracking was observed in the road. The cracks were of limited size, i.e. maximum width 2 — 3 inches, and extended into the road shoulder. In reference to Panel 12 Right, TCC enlisted the services of SubTerra, Inc. to evaluate the potential for rocks to reach RCR No.33. The results of his investigation are presented in Exhibit 7F -1, Rockfall Hazard Assessment — Pond 12 Right. TCC will follow the recommendation presented in this Exhibit. Powerline The powerline that is located to the north of the 18 Right Gateroad is outside of the area to be subsided during mining associated with the proposed five year permit term (1998 -2003) and the angle of draw form the 16 Right longwall panel. The powerline is adjacent to a gateroad, however, TCC's extensive mining experience indicates that the powerline will not be impacted. The reasoning for this is two -fold, the first being limited extraction APPROVED JUN 2 b 2000 PR 99 -05 2.05 -181.5 5/03/00