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iz Energy Fuels Coal, Inc. Southfield Mine SEMI-ANNUAL SUBSIDENCE MONTCORING REPORT Period: January 1 through June 30, 2002 Introduction The semi-annual subsidence monitoring report compares field survey monitoring data to permit predictions for inventoried structures. Summarized survey data are shown in attached Table 1, Semi-Annual Subsidence Monitoring Data. These data show location and orientation of monuments and structures for the reporting period. Additionally, the original survey data and current quarterly survey data for all subsidence monitoring locations aze shown on attached Table 2, Current Report Data. Field surveys are conducted quarterly on the structure monuments shown on Table 1. EFCI will conduct a survey of the South Grid monument network only prior to bond release for the area containing the monuments, as approved in the permit. EFCI performed two quarterly subsidence surveys of the structures shown on Table 1 during the nVporting period. The surveys were conducted using differential GPS equipment for both horizontal and vertical control. Discussion of the subsidence data, and any current visual observation information, is shown below. Discussion 1. Structures Structures monitored quarterly for subsidence include the Thompson Ranch buildings, the Florence City water line, and the Newlin Creek point. Summarized survey data for these structures are shown on accompanying Table 1, Semi-Annual Subsidence Monitoring Data Summary. Location of the structures and monuments with respect to the Mine layout are shown on Map 17 in the permit application. Discussion of survey monitoring data compared to permit predictions for inventoried structures follows below. 1.1 Thompson Ranch Structures Survey data for the reporting period indicate vertical changes, compazed to original data, ranging from 0 to -0.03 feet. These data are consistent with values obtained during previous monitoring periods which show that little or no subsidence has occurred in this azea. No subsidence is expected since only advance mining utilizing lazge support pillars occurred below the ranch azea. in addition, there are no physical indications of subsidence on or near the monitored structures.