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Subsidence Surveys <br />• Stipulation 12 requires that five subsidence monitoring stations in Jerry Creek Canyon and <br />Coal Canyon be surveyed to detect movement or change in elevation. Two surveys were <br />conducted during 1999. Table 1 shows the results of the surveys conducted since 1996. These <br />results indicate no subsidence at any of the measured locations. <br />TABLE 1 -SUBSIDENCE MONITORING SURVEY DATA COMPARISON <br />• <br /> SUBSIDENCE MONUMENT ELEVATIONS <br />Date SM01 SM02 SM03 SM04 SM05 <br />Fa111996 4869.36 4898.68 4970.44 4985.68 5121.62 <br />04/17/97 4869.30 4898.53 4870.47 4985.74 5121.65 <br />12/18/97 4869.45 4898.71 <br />10/05/98 4869.24 4898.56 4970.27 4985.72 5121.55 <br />12/15/98 4869.23 4898.56 4970.27 4985.72 5121.55 <br />08/30/99 4869.54 4898.90 4970.65 4986.11 5121.81 <br />11 /23/99 4869.41 4898.81 4970.14 4985.97 5121.74 <br />Minimizing Subsidence <br />Both the Roadside North Portal Mine and the Roadside South Portal Mine are currently idle <br />• <br />with no immediate plans for continued operations. <br />Conclusion <br />There is no evidence of subsidence related damage caused by the mining operaton in the <br />last year. No dangerous subsidence related features were located during the surface investigation <br />or survey of the subsidence monuments. The operator was not notified that subsidence has <br />affected any structures, water supplies or environmentally sensitive areas. <br />1999 Subsidence Report Page 4 <br />12/29/99 <br />