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Semi-Annual Subsidence Monitoring Reps <br />Period: January 1, 2000 -June 30, 2000 <br />Page 2 <br />1.2 Newlin Creek Point <br />Survey data for the Newlin Creek point show a change of +3.98 feet of subsidence, compared to <br />the original survey data, through the 2nd quarter of 2000. Survey error on the 2nd quarter survey <br />is indicated by the abnormal values for both the vertical and horizontal change as shown on Table <br />1. Similar to the survey data for the ranch structures, above, it is not likely that any subsidence <br />has occurred at this monument. No mining operations have occurred in the vicinity of this survey <br />point since 1982 to cause additional subsidence. <br />1.3 Florence Water Line <br />Survey data obtained at the eight monuments along the Florence Water Line indicate no <br />additional subsidence occurring in the area of the water line during the reporting period. The <br />amount of measured subsidence at these monuments, as compared to original data, ranged fmm <br />0.0 to 3.06 feet. No recent mining has been done in the vicinity of monitoring locations that <br />would cause additional subsidence. <br />The maximum measured subsidence along the water line occurs at Monument G, with a current <br />deflection of 3.06 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 new surface cracks have appeared on the surface of the Newlin Creek light-use road south of <br />the topsoil pile area. Previous tension cracks continue to heal as a result of weathering during the <br />reporting period. <br />No other cracks or other subsidence related features were observed during the reporting period. <br />Previously observed surface cracks, primarily on County Road 15, have healed and not <br />reappeared. <br />Conclusions <br />Subsidence monitoring of structures indicates that subsidence is occurring only at certain locations <br />along the water line, and that the magnitude of displacement is within predicted values. Only <br />minor additional subsidence is expected to occur at the structure monitoring locations. <br />