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A monitoring plan for the Archer -Hayden powerline was approved by the powerline <br />operator and incorporated into Exhibit 7e-7 of the PAP. No significant damage or <br />interruption of power was experienced during the subsidence of the Archer -Hayden, <br />Western Area Power Administration, Tri-State and Public Service powerlines. <br />With PR -10, TC proposes to undermine and subside portions of the Yampa Valley <br />Electric Line serving the mine located above the SRT, 6RT and 7RT Longwall panels <br />in sections 15, 14 and 11 in Township 5 North, Range 86 West. Twentymile Coal <br />Company has undermined and subsided powerlines in the EMD and NMD without any <br />significant damage or disruption of service. Twentymile Coal anticipates the <br />powerlines overlying Longwall panels 5RT, 6RT and 7RT proposed with PR -10 will <br />react in the same manner; however a monitoring and control plan is included in the <br />PAP. TC may reroute power in the unlikely event the powerline is temporarily <br />impacted. Once the line is stabilized, power would be restored to the line. <br />Existing Residences/Structures <br />Three residences were undermined and subsided during the mining of Eastern Mining <br />District longwall panels 6R and 5R. One residence is occupied year-round; one is <br />inhabited on a limited basis, while the third was vacant and owned by Twentymile <br />Coal. <br />Twentymile Coal has a subsidence agreement with the owners of the residences not <br />owned by Twentymile Coal. Twentymile repaired subsidence damage to the smaller <br />residence and replaced the larger residence. Persons living in the larger residence <br />were relocated while mining and structure replacement occurred in the fall of 1999 and <br />spring of 2000. <br />Foidel Creek/Middle Creek <br />No specific subsidence control plan is proposed for Foidel Creek or Middle Creek. <br />Recommendations presented in Exhibit 7i, Subsidence Effects on Streams, call for <br />channel morphology to be evaluated if headcutting or incising of the channel occurs <br />for more than 400 feet from the point of origin of the headcut. Any proposed <br />mitigation would be based on the results of this evaluation. <br />Portions of Foidel Creek will be subsided by mining proposed with PR -10. Exhibit 7K <br />submitted with PR -10 presents the subsidence evaluation and predictions for both <br />Foidel and Fish Creek. TC has previously undermined these creeks before <br />successfully and expects them to react in a similar fashion. <br />Fish Creek <br />Twentymile Coal Company proposes to undermine and subside Fish Creek and its <br />associated alluvial valley floor. Further discussion of subsidence of the Fish Creek <br />and its AVF is discussed in Section XVIII, Operations on Alluvial Valley Floors, <br />found beginning on page 37. Exhibit 7K submitted with PR -10 presents the <br />Page 38 of 52 <br />