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Energy Fuels Coal, Inc. Southfield Mine Semi-Annual Subsidence Monitoring Report (Period May 1, 1994 through October 31, 1994) Introduction This report presents a summary of all subsidence survey data and discussion of these data. The discussion of subsidence data includes comparisons of measured subsidence with the values predicted in the permit application. Subsidence data is presented on three accompanying summary tables. In addition, data from the high-resolution monitoring grid is presented graphically on two cross-section diagrams. Discussion 1. High-Resolution Grid The 23 monuments comprising the high-resolution grid are surveyed on asemi-annual basis for the purpose of determining vertical displacements and draw angle resulting from room and pillar mining. Summarized survey data for the period of this report are shown on Table 1, South Subsidence Grid. These data are also shown, in cross-section format, on Figures 1 and 2. A review of the survey data for the period of this report indicates that only minor additional subsidence has occurred in the monitoring area. This trend is consistent with previous semi-annual monitoring periods. In addition, the estimated draw angle of 26 to 28 degrees shown on Figure I is consistent with previous survey data. Ground movement in the area of the survey monuments is minimal based on the survey during the period of this report. Vertical change of the monuments since the previous survey measured only a few hundredths of a foot, indicating that the ground has consolidated and is becoming stabilized. The maximum measured subsidence occurs at Monument 15, with a total displacement of 2.26 feet. This value is less than half of the maximum predicted value of 5.40 feet presented in the permit application. The high-resolution grid monitoring data for this reporting period are consistent with previous reporting periods and within predicted values. Only minor additional subsidence is expected to occur in the area of the survey grid. 2. Structures Structures monitored quarterly for subsidence include the three Thompson Ranch buildings, the Florence city water line, and the Newlin Creek point. Summarized survey data for these structures are shown on accompanying Table 2.