2009-10-30_PERMIT FILE - C1982056A (5)

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unanticipated changes resulting from the undermining of the creeks. The survey will be completed during favorable (i.e. not ice-covered) low flow periods before and after the mining episode. • Face Extension and Gateroad Development fl'R 99-33) TCC will continue to follow the monitoring plan presented in permit revision 904. There are no new structures which warrant a modification to the existing plan. NMD (Panels 12 Right through 16 Right)(PR 99-05) As was proposed in the Eastern Mining District application (PR 97-04), TCC is not planning on establishing further subsidence monuments except as described below. The ongoing subsidence monitoring work has demonstrated that TCC's subsidence predicfions were conservative and provided acceptable descriptions of expected subsidence. Any further subsidence monitoring work would just be further verification of these predictions and is not warranted. Uuion Pacific Railroad (formerly Southern Pacific) The monitoring will continue until the face is 1,500 feet past the tracks. In the event there are grade changes, which could disrupt traffic, the railroad tracks will be repaired accordingly. The anticipated repair would focus on re- leveling the track and/or having a slow speed restriction on during that time period. The monitoring and repair of the track will occur until mining of panels 12 through 16 of the Northern Mining District have been completed. The monitoring and repair will occur periodically throughout the time the track is undermined along the track- traversed portions of the panels. During the repair of the track, it is anticipated additional ballast will be required to re-level the track. This will be replaced on an as needed basis. Either Twentymile or Union Pacific will stockpile additional ballast for the repair work. • A Yampa Valley Electric Powerline services a railroad relay overlying the 14 Right Panel. The line is a single pole construction and TCC does not propose any formal monitoring of the line. TCC's prior experience with these types of lines indicates subsidence does not significantly impact them. There is a baclFUp power source at the relay in the event the line were damaged, this power would be available at the relay. In the event the line were damaged TCC would repair it and return electric service to the relay. Fish Creek and Foidel In addition to the pre and post-mining longitudinal profiles of the respective creeks, TCC will survey the pool areas that develop over each of the panels located beneath the creeks. The results ofthe survey will be incorporated into the appropriate semi-annual subsidence report. TCC will utilize the hydrologic monitoring plan presented in Exhibit 4e-7 to determine the impact from subsidence in Fish Creek. In general, the details of the plan are as follows: The monitoring plan will be a dynamic one in that sites will be established in panels that eventually will be subsided and destroyed and replaced by a downstream station. Prior to destruction of a site the replacement site will be installed tofacilitate a smooth transition to it. For example, surface station 1002 will be lost during the mining of the 13 Right longwal] panel. The replacement site will be installed in the SW/4, SE/4 of section 17, TSN, R86W. The replacement site will be monitored at the same frequency and for the same parameter as station 1002. Alluvial well 006-AW 2 may be lost also when longwal] panel 13 Right is mined. The replacement well will be established in the SW/4, SE/4 of Sectionl7, TSN, R86W. This well will be monitored as per the same frequency and for the same parameters as we11006-AW-2. Refer to the above. Additionally, Fish Creek will be surveyed before and after longwall mining of a panel to program a channel profile. The profile will be compared to determine if there are unanticipated changed resulting from the undermining of the creek. The surveys will be performed during probable low flow period before and after the mining episode. MR 02-179 2.05-191.4 08/06/02