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FLORENCE WATER LINE STRUCTURE Survey data for the Florence water line monuments is on Table 2, Subsidence Monitoring Data Summary. The data indicates only minor subsidence occuring at the eight monument locations. Measurements indicate vertical displacements ranging from 8.31 to A.68 feet, with the exception of Monument 'E', below. These values are not consistent with previous surveys, and probably the result of a surveyed benchmark error. The maximum total subsidence of 1.98 Eeet occurs at Monument 'E',which is the only monument located above a retreat mined area of the mine. This amount of subsidence is well below the maximum subsidence predicted in the permit application. The next monitoring period should indicate subsidence values consistent with previous monitoring periods. Only minor additional subsidence, resulting from material consolidation, is expected to occur at this location. SOUTH SUBSIDENCE GRID Data collected from surveys of the high-resolution grid (South Grid) ar.e presented on Table 1, Subsidence Monitoring Data Summary. In addition, total displacement data is presented graphically, in cross section form, on Figures 1 and 2. A review of the data indicates total the area of the 23 monuments ranging from maximum subsidence occurred at monument expected center of the subsidence trough. draw is estimated to range from 29 to 29 cross section Figure 1. subsidence occuring in e.ea to 2.20 Eeet. The 15, located near the The apparent angle of degrees as measured on The apparent angle of draw and maximum subsidence agree favorable with the subsidence predictions in the permit applica- tion. The angle of draw range in the permit area was predicted to be 2B to 25 degrees based on probable subsidence ranging from 1.46 to 3.22 feet. The permit contains a projected worst case vertical subsidence range of 1.46 to 6.48 feet. The rate of subsidence Eor all monuments continues to be minor, consistent with semi annual report periods Eor the past two years. The data suggests that small surface deflections are resulting from material consolidation rather than subsidence. It is predicted, therefore, that only minor additional ground move- ment will occur in the South Grid area.