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Southfield Mine Semi-Annual Subsidence Monitoring Report Period: January 1 through June 30, 2002 Page 2 1.2 Newlin Creek Point Survey data for the Newlin Creek point show a change of -0.33 feet of subsidence, compazed to the original survey data, through the 2nd quarter of 2002. Similaz to the survey data for the ranch structures, it is not likely that any subsidence has occurred at this monument due to advance mining only. No mining operations have occurred in the vicinity of this survey point since 1982 to cause additional subsidence. 1.3 Florence Water Line Survey data obtained at the nine monuments along the Florence Water Line indicate minor or no additional subsidence occurring in the area of the water line during the reporting period. Only minor additional subsidence is anticipated along the water line since no mining has been done in the vicinity of any of the monitoring points after May 1996. The amount of measured subsidence found at the water line monuments, as compared to original data, ranged from -0.02 to -3.23 feet. The maximum measured subsidence along the water line occurs at Monument G, with a current deflection of -3.23 feet as compared to the original survey. This value is within the permit maximum expected and worstcase expected subsidence values of 2.79 and 4.36 feet respectively. Visual Observations No cracks, sink holes, or other subsidence features related to Southfield's mining operations were observed during the reporting period. Previously observed surface cracks, as seen primarily on County Road 15, have healed and not reappeared. Conclusions Subsidence monitoring of structures indicates that only minor subsidence is occurring at locations along the Florence water line, and that the magnitude of displacement is within predicted values. Only minor additional subsidence is expected to occur at the structure monitoring locations.