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Southfield Mine Semi-Annual Subsidence Monitoring Report <br />Period: January 1 through June 30, 2003 <br />Page 2 <br />1.2 Newlin Creek Point <br />Survey data for the Newlin Creek point show a change of -0.30 feet of subsidence, compared to <br />the original survey data, through the 2nd quarter of 2003. Similar to the survey data for the ranch <br />structures, it is not likely that any subsidence has occurred at this monument due to advance <br />mining only. No mining operations have occurred in the vicinity of this survey point since 1982 <br />to cause additional subsidence. <br />1.3 Florence Water Line <br />Survey data obtained at the eight monuments along the Florence Water Line indicate minor or no <br />additional subsidence occurring in the area of the water line during the reporting period. Only <br />minor additional subsidence is anticipated along the water line since no mining has been done in <br />the vicinity of any of the monitoring points after May 1996. The amount of measured subsidence <br />found at the water line monuments, as compared to original data, ranged from -0.10 to -3.20 <br />feet. <br />The maximum measured subsidence along the water line occurs at Monument I, with a current <br />deflection of -3.20 feet as compared to the original survey. This value is within the permit <br />maximum expected and worst~ase expected subsidence values of 2.79 and 4.36 feet respectively. <br />Visual Observations <br />No cracks, sink holes, or other subsidence features attributable to Southfield's mining operations <br />were observed during the reporting period. Previously observed surface cracks, as seen primarily <br />on County Road 15, have healed and not reappeared. <br />Conclusions <br />Subsidence monitoring of structures indicates that only minor subsidence is occurring at locations <br />along the Florence water line, and that the magnitude of displacement is within predicted values. <br />