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5. The duration of subsidence effects at each structure is expected to be between 25 and 35 -days. <br />6. In the case of the Archer -Hayden and Craig -Hayden -Steamboat lines, the length of the traveling <br />subsidence profile means that each structure will react independently which should for the most part <br />eliminate the potential for complex interactions. <br />7. Subsidence, tilt and strain magnitude at each Archer -Hayden and Craig -Hayden -Steamboat structure are <br />predicted to be lower than previously experienced by WAPA's line that crossed the Eastern Mining <br />District and by these two lines when they were previously undermined by 19 -Right in the Northern <br />Mining District. <br />8.5. Water Wells <br />The evaluation presented in Section 7 predicts impacts to wells completed in the Wolf Creek Seam and its <br />immediate overburden. Minor impacts may also occur in shallow overburden wells but are likely to be minor <br />with recovery within one year after undermining. <br />8.6. Monitoring Requirements <br />As noted in the introduction, Twentymile Coal, LLC has collected and submitted a large amount of subsidence <br />data from monitoring coal extraction in the Wadge Seam. They have also monitored subsidence of the Power <br />Lines, Fish and Foidel Creek and the Energy Spur railroad track during sequential undermining. We recommend <br />that monitoring both ground subsidence and structure response continue focusing on verifying the predictions <br />made herein. Additional monitoring requirements associated with each of the evaluated structures <br />21 <br />