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:. Energy Fuels Coal, Inc. Southfield Mine III IIIIIIIIIIIII III ~~ APR3p~~ Division of Ming~ls B G SEMI-ANNUAL SUBSIDENCE MONTCORING REPORT Period: January 1, 2000 -June 30, 2000 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 are shown on attached Table 2, Current Report Data. Field surveys are conducted on the structure monuments shown on Table 1. EFCI will survey the South Grid monument network after mining operations have permanently ceased, as approved in the permit. EFCI performed two quarterly subsidence surveys of the structures shown on Table I during the reporting period. The surveys were completed using conventional EDM equipment for both horizontal and vertical control. Discussion of the subsidence data, and any current visual observation information, is shown below. 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 aze 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, compared to original data, ranging from +0.10 to +0.14 feet. A survey error on the 2nd quarter survey resulted in the unusual horizontal change for the North House and Barn as shown on Table 1. No subsidence is expected since mining has not occurred below the ranch area that would cause subsidence. in addition, there aze no physical indications of subsidence on or near the monitored structures.