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Requirement <br />Regulation <br />Require- <br />ment <br />comp lied <br />with? <br />(yes / no) <br />Comment <br />Q. Parameters to be <br />analyzed in <br />Table 4.8 -13 <br />of CDRMS <br />groundwater <br />samples <br />mining <br />permit C -81- <br />010 <br />yes <br />Based on previous analysis by DRMS staff, the Third White <br />Sandstone aquifer is the only bedrock stratigraphic unit having <br />significant permeability that is in the groundwater flow path of any <br />coal spoil leachate; therefore, the Third White Sandstone is the <br />only bedrock stratigraphic unit whose ground water quality may be <br />negatively impacted by mining at Trapper. Well GP -9 monitors the <br />Third White Sandstone immediately downgradient from Trapper's <br />pits at a location where a leachate plume can be expected to form, <br />as explained in the PHC (Section 4.8.3 of the permit). Well GP -9 <br />is Trapper's ground water point of compliance for the Third White <br />Sandstone as explained on permit page 4 -242. In general, 2010 <br />data from well GP -9 does not exceed Basic Standards for Ground <br />Water for a Domestic Use classification. (This classification is for <br />the Third White Sandstone in a Specified Area that extends <br />outward from Trapper's northern permit boundary on the east half <br />of the mine to the axis of the Big Bottom Syncline, a distance <br />R. Basic Standards <br />CWQCC <br />ranging between 1/2 and 3/4 mile from the boundary.) There are <br />for Ground Water <br />regulations <br />41.4 and 41.5 <br />yes <br />exceedances of drinking water standards for Fe and Mn; however, <br />Fe and Mn exceedances also occurred in GP -9 prior to mining in <br />the area upgradient of this well. Furthermore, other hydrogeologic <br />and water quality factors (e.g., concentrations of TDS and sulfate) <br />indicate that coal spoil leachate has not reached GP -9. <br />Trapper is not expected to negatively impact water quality in the <br />Third White Sandstone aquifer outside Flume Gulch, as <br />documented previously by DRMS staff. <br />Flume Gulch alluvium could also be contaminated by coal spoil <br />leachate. The Coy well is the ground water point of compliance for <br />the Flume Gulch alluvium, as explained on page 4 -242 of the <br />permit application. Data from the Coy well in 2010 indicate no <br />exceedances of the Basic Standards for Ground Water for the <br />classification of Agricultural Use. <br />Page 3 <br />