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<br />Requirement Require- <br />ment Complied with? <br />Comment <br /> citation (yes / no) <br /> The disturbance to the hydrologic balance within <br />U. Minimization of and adjacent to the permit area caused by mining <br />disturbance to the CDRMS and reclamation at the Eagle Mines is the <br />hydrologic <br />regulation <br />yes minimum that can be expected from an <br />balance within <br />4.05.1(1) underground mining operation at this location. <br />and adjacent to Use of best management practices indicates <br />the permit area minimization of disturbance to the hydrologic <br /> balance. <br /> Mining and reclamation at the Eagle Mines have <br /> not caused impacts to the hydrologic balance <br /> outside the permit area. The probable hydrologic <br /> consequences (PHC) section of the permit <br /> application projects future impacts to be minor. <br /> In 4~h quarter 2006 Eagle's mine water discharge <br /> had TDS concentration of 900 mg/1, similar to <br />Prevention of <br />V past years. (An all-time high of 2,600 mg/1 <br />. <br />material damage CDRMS occurred in 2005 when the pumps were reactivated <br />to the hydrologic regulation yes after being idle for a few months.) This mine <br />balance outside 4.05.1(1) water was discharged at a rate of 3.0 cfs to the <br />the permit area Williams Fork River when the receiving river <br /> water probably had TDS of less than 300 mg/ with <br /> flow of around 30 cfs. This discharge would have <br /> caused TDS in the river to rise to 355 mg/l, <br /> calculated as follows: [(30 cfs) X (300 mg/1) + (3.0 <br /> cfs) X (900 mg/1)] / [(30 cfs + 3.0 cfs)] = 355 <br /> mg/l. The calculated 355 mg/I is well below the <br /> CDRMS material damage suspect level of <br /> approximately 700 mg/1 for the Yampa River <br /> Basin. <br />W. Requirement to The previously mentioned calculated TDS of 355 <br />keep information mg/1 in the Williams Fork River is less than the <br />current maximum predicted in the Probable Hydrologic <br /> Consequences (PHC) section of the permit <br /> CDRMS application. Long-term (following cessation of <br /> regulations mining) mine water pumping will cease at the <br /> 2.05.6(2) and yes Eagle Mines but there may be mine water seepage <br /> 2.03.3(1) of less than 1 cfs to the Williams Fork River <br /> through the coal seam outcrops (see DRMS <br /> Memorandum in SL-2 bond release file, dated <br /> 4/5/05). The PHC adequately accounts for this <br /> ossible see a e. <br />X. Adequacy of CDRMS <br />ground water regulation yes <br />monitoring 4.05.13(1) <br />rogram <br />Y. Adequacy of CDRMS <br />surface water regulation yes <br />monitoring 4.05.13(2) <br />ro ram <br />Page 4 <br />