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<br /> <br />Requirement <br />Require- <br />ment <br />citation Require- <br />ment <br />complied <br />with ? (yes <br />/no <br /> <br />Comment <br /> Ground water points of compliance are not warranted for the <br /> West Elk Mine because the mine does not have the potential to <br /> cause what is considered a negative impact to the quality of <br /> ground water under CWQCC Regulation 41.5(C)(6)(b)(i). <br /> CWQCC Regulation 41 S(C)(6)(b)(i) indicates an exceedance of <br /> ambient ground water quality would constitute a negative impact <br /> and CWQCC Regulation 41.5(C)(6)(b)(ii) requires the use of <br /> water quality data subsequent to January 31, 1994 for estimating <br /> ambient quality because the West Elk Mine originated before <br /> that date. <br /> In addition, the mine does not have the potential to negatively <br /> impact the quality of ground water in bedrock units because of <br /> the low permeability of those units (see following discussion). <br /> Rollins Sandstone -Although the Rollins Sandstone lies directly <br /> beneath the mined sequence, high head and low permeability in <br /> this unit precludes its invasion by water from the mine <br /> workings; therefore, the mine does not have the potential to <br />P Basic CWQCC degrade ground water in the Rollins Sandstone. Flow from the <br />Standards regulation Rollins into the mine workings is more likely to occur than flow <br />for Ground s yes from the workings to the Rollins. <br />Water 41.4 and <br /> 41.5 Sandstone and coal beds within the mined sequence - Holes <br /> drilled to these units produce significant volumes of gas, <br /> indicating the porosity is saturated with gas and water. The gas <br /> saturation precludes the use of the water from these units. <br /> Leachate migration from the mine workings to these sandstone <br /> or coal beds would not further impair the use of the water in <br /> these beds; therefore, the mine does not have the potential to <br /> degrade water quality in these beds. <br /> Barren Sandstone - This unit directly overlies the mined <br /> sequence. This unit is outside the flow path of leachate <br /> discharged from the mine workings, should a dischazge occur; <br /> therefore, the mine does not have the potential to degrade water <br /> quality in this unit. <br /> North Fork Alluvium -The mine has the potential to <br /> significantly increase TDS in North Fork alluvium (see attached <br /> analysis), but such an increase would not constitute a negative <br /> impact under CWQCC Regulation 41.5(C)(6)(b)(i) (see <br /> recedin ex lanation). <br />Q. Restoration <br />of ground <br />water CDMG Mining in the permit area cannot be expected to significantly <br />rechazge to regulation yes decrease infiltration of snowmelt or runoff into the subsurface. <br />approximate 4.05.1 1(3) Monitoring data do not show an impact on recharge. <br />premining <br />rate <br />Page 4 <br />