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SEMI-ANNUAL SUBSIDENCE MONITORING REPORT Page 2 Surveyed high-resolution grid monitoring data for this reporting period aze 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 aze shown on accompanying Table 2. Location of the structures and monuments with respect to the Mine layout are shown on Map 17 in the permit application. Survey data for the ranch structures indicate that no subsidence is occurring. This data is consistent with previous subsidence surveys. No retreat mining operations occurred in the azea of these structures. The Newlin Creek point similarly shows no additional subsidence during the reporting period. This data agrees with preceding monitoring periods. No mining operations occurred in the area of this survey point since the mining section is closed and sealed. Survey data from the Florence Water Line indicates subsidence occurring at Monuments C, D, and I. The amount of subsidence occurring during the reporting period was minimal. The maximum measured subsidence has occurred at Monument I, totalling 3.03 feet as of the most recent survey. This value is between the permit maximum expected and worst~ase expected subsidence values of 2.79 and 4.36 feet respectively. The rate of subsidence at Monument I has decreased compazed to the previous period, and is expected to minimal in the future. During the reporting period, Monument D along the water line was destroyed by contractors while repairing County Road 15. EFCI reset and surveyed Monument D close to its original location in January 1995. There is no visual surface cracking in the vicinity of any structures. !n addition, there are no indications that subsidence due to mining is adversely affecting operation of the Florence Water Line. Subsidence monitoring of structures indicates that subsidence is occurring only at locations along the 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.