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<br /> <br />Requirement <br />Requirement <br /> <br />citation Require- <br />ment <br />complied <br />with ? <br />es / no <br /> <br />Comment <br /> Ground water points of compliance are not warranted for the West Elk Mine because the mine does <br /> not have the potential to cause what is considered a negative impact to the quality of ground water <br /> under CWQCC Regulation 41.5(C)(6)(b)(i). CWQCC Regulation 41.5(C)(6)(b)(i) indicates an <br /> exceedance of ambient ground water quality would constitute a negative impact and CWQCC <br /> Regulation 41.5(C)(6)(b)(ii) requires the use of water quality data subsequent to January 31, 1994 for <br /> estimating ambient quality because West Elk's operations preceded that date. <br /> In addition, the mine does not have the potential to negatively impact the quality of ground water in <br /> bedrock units because of the low permeability of those units (see following discussion). <br /> Rollins Sandstone -Although the Rollins Sandstone lies directly beneath the mined sequence, high <br /> head and low intergranular permeability in this unit precludes its invasion by water from the mine <br /> workings; therefore, the mine does not have the potential to degrade ground water in the Rollins <br /> Sandstone. Flow from the Rollins into the mine workings is more likely to occur than flow from the <br /> workings to the Rollins. <br />P. Basic CWQCC <br />Standards for <br />Ground Water regulations <br />41.4 and 41.5 yes Sandstone and coal beds within the mined sequence - Holes drilled to these units produce <br /> significant volumes of methane gas, indicating the porosity is saturated with gas and water. The gas <br /> saturation precludes domestic or agricultural use of the water from these units. Leachate migration <br /> from the mine workings to these sandstone or coal beds would not further impair the use of the water <br /> in these beds; therefore, the mine does not have the potential to negatively impact water quality in <br /> these beds. <br /> Barren Sandstone - This unit directly overlies the mined sequence. The unit is outside the flow path <br /> of leachate discharged from the mine workings, should a discharge occur; therefore, the mine does <br /> not have the potential to degrade water quality in this unit. <br /> North Fork Alluvium - The mine has the potential to significantly increase TDS in North Fork <br /> alluvium (see analysis attached to DRMS's review summary of 2004 annual hydrology report), but <br /> such an increase would not constitute a negative impact under CWQCC Regulation 41.5(C)(6)(b)(i) <br /> because this regulation requires the use of water quality data subsequent to January 31, 1994 for <br /> estimating ambient quality. <br />Page 4