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map(s), and timetable(s) sufficient to describe the azeal extent of the proposed undereround workines and the • stratum to be affected. RESPONSE The mine openings are located in the NE'/. of the NE'/. of Section 32, TSN, R86W, Routt County, Colorado. Currently, these portals provide the sole openings to the mine for men and materials, utility services and ventilation. Additionally, another portal was driven northeast of the original portals. This portal provides man and natural access into the mine. This portal is shown on Map 23, Mine Plan. The other openings into the mine include the Fish Creek Borehole and ventilation shaft. These two facilities are shown on Map 26, Fish Creek Borehole Area Facilities and Access Road. Surface disturbances are discussed under the response to 2.05.3(3) below. Disturbance boundaries are defined by posts with bright fluorescent paint, fenced areas, orange surveyor markers, or the site being fenced in. Production of coal began from the portal slopes. A set of envies were driven toward the north (1~' Main North). The 1" Main north will be developed approximately 8,000 feet to the north. Once this initial development has been completed the north mains will be angled to the west and driven to the north permit boundary. At a point approximately 1,850 feet north of the portals, a new set of mains (l~' Main West) was turned off toward the west and were developed approximately 4,700 feet. Approximately 500 feet to the north of the 1" Main West a second set of mains will be driven. These mains will be developed approximately 2700 feet to the west. During the initial 2700 feet, the mains typically will consist of six entries. Depending upon conditions, the number of entries may vary, up to a maximum of seven. Once development has progressed to this point, the 6-7 entries will be necked down to a three entry gate road system for the remainder of the panel. • A set of submains will be driven from l~' left heading and will extend approximately 3000 feet to the south. These submains will consist of 5 entries and the gate roads for panels 7 through 9 will be developed from them to the west. These submains are shown as I" South submains on Map 23. The first set of 6 longwall panels will be developed to the west from 1" Main North. These panels will extend until they reach either of two anticipated faults or until the 25° angle of draw line from the panel reaches the buffer zone of Fish Creek, whichever comes first. An estimated 12.3 million tons will be recovered from this first block of Longwall panels. In order to explore and assess the fault zone on the west end of the panels, TCC wishes to extend the l~', 2"" and 3rd Left entries beneath the Fish Creek AVF. These entry extensions will be similar in nature to the previously approved 2"d West Main entries, which were identified in the 1986 Findings of Compliance Document as having no potential adverse impacts upon the AVF. This determination is further supported by a Wilson Pillar Stability Analysis which yielded a safety factor of 2.2 for the anticipated 35'x 80' pillar design of the proposed extensions. TCC does not anticipate any major inflows to be encountered during the proposed extensions, but should excessive inflows be encountered TCC will seal the affected entry extension. TCC also plans to partially extend Panels 5 and 6 beneath the designated Fish Creek AVF. While extension was not contemplated in the original Foidel Creek mine plan, mining experience indicates that subsidence associated with longwall extraction beneath the designated AVF area will not result in significant surface impacts. In order to objectively assess potential impacts on the designated AVF due to proposed panel extension, TCC completed subsidence projections and evaluated related effects. The subsidence projections are based on existing available subsidence data for TCC's ongoing longwall operations and reflect an increase in panel width for Panel 6 from 625 feet (current panel width)to 850 MR 99-166 2.05-12 APPROV~0 tf~V o ~ 1g~9 10/4/99