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Requirement Require- ment Complied with? Comment citation (yes I no) T. Prevention of impacts to The postmining land uses of rangeland/wildlife, ground water CDRMS pastureland, and cropland will not use ground water. that adversely regulations Yes Consequently, any impact to ground water will not impact the 4.05.1(2) and impact the postmining land use in the permit azea. postmining land 4.05.11 use within the ermit area The disturbance to the hydrologic balance within U. Minimization of and adjacent to the permit area caused by mining disturbance to the CDRMS and reclamation at the Eagle Mines is the hydrologic regulation es minimum that can be expected from an balance within 4.05.1(1) y underground mining operation at this location. and adjacent to Use of best management practices indicates the permit area minimization of disturbance to the hydrologic balance. Mining and reclamation at the Eagle Mines have not caused impacts to the hydrologic balance outside the permit area. The probable hydrologic consequences (PHC) section of the permit application projects future impacts to be minor. In 4'h quarter 2005 Eagle's mine water discharge reached a new high for TDS of 2600 mg/I, The V. Prevention of discharge occurred as the pumps were reactivated material damage CDRMS after being idle for a few months. This mine water to the hydrologic regulation yes having TDS of 2600 mg/1 was dischazged at a rate balance outside 4.05.1(1) of 3.33 cfs to the Williams Fork River when the the permit azea receiving river water probably had TDS of less than 300 mg/ with flow of around 30 cfs. This discharge would have caused TDS in the river to rise to 530 mg/I, calculated as follows: [(30 cfs) X (300 mg/I) + (3.33 cfs) X (2600 mg/I)] / [(30 cfs + 3.33 cfs)] = 530 mg/I. The calculated 530 mg/I is well below the CDRMS material damage suspect level of approximately 700 mg/I for the Yampa River Basin. W. Requirement to The previously mentioned calculated TDS of 530 keep information mg/I in the Williams Fork River is less than the current maximum predicted in the Probable Hydrologic Consequences (PHC) section of the permit CDRMS application. Long-term (following cessation of regulations mining) mine water pumping will cease at the 2.05.6(2) and yeS Eagle Mines but there may be mine water seepage 2.03.3(1) of less than 1 cfs to the Williams Fork River through the coal seam outcrops (see DBMS Memorandum in SL-2 bond release file, dated 4/5/05). The PHC adequately accounts for this ossible see a e. Page 4