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<br />• <br />J <br />1.0 Hvdrabgir Data lnrrrprerarian and lmpaa Asstssmrnt Jor the Permit and Adjacrra Area: <br />cracks in subsided overburden, no variance <br />in spring flows have been recorded. At this <br />time, the hypothesis that current mining has <br />had little affect on shallow groundwatets <br />within the Barren Member appears to be <br />substantiated. <br />2.3.3 "F" Seam <br />Water levels in SOM-2-H, persistent at an <br />elevation near 7335' to 7330' from 1982 <br />through 1993, started dropping in 1994 and <br />continued to drop 35' this water year, for a <br />cumulative drop of 65' from baseline. This <br />well is located approximately 700 feet south <br />of the B-Seam Mains. Mine workings may <br />be dewatering the F-seam in the vicinity of <br />SOM-2-H. This water level drop may be <br />attributable to slope failures in the vicinity <br />of the well. Another F-seam well, SOM-16- <br />H, is located at a similaz distance from <br />mining activities and did not show a water <br />level decline. <br />bevels of manganese in SOM-16-H <br />exceeded the baseline maximum 0.04 mg/1 <br />during WY 1995. SOM-16-H exhibited a <br />maximum concentration of 0.34 mg/1. <br />Previously, elevated concentrations of <br />manganese readings were associated with <br />high concentrations of TSS and reflect the <br />sampling methodology rather than any <br />impacts from mining. Chloride <br />concentrations in SOM-2-H substantially <br />exceed domestic standards for chloride. <br />2.3.4 "E" Seam <br />The "E" Seam is located below the inactive <br />(mining) "F" Seam and above the active <br />"B" Seam. Well SOM-23-H-2, historically <br />dry, had enough moisture on the casing wall <br />to preclude accurate water level measure- <br />ments. It is located approximately a mile <br />A}{7t-95.210/OS/ I S/96(I : J8 pm) <br />south of the nearest mining activity. Water <br />elevations ranging from 7281.9' to 7503.3' <br />were observed in WY 1995. The water is <br />characterized as an alkaline, saline (TDS is <br />820 mg/1), sodium bicarbonate water of low <br />hardness. <br />2.3.5 "B" Seam <br />Well SOM-C-72-H was "lost" due to <br />through-mining in WY 1994. This loss was <br />anticipated. Sources of water and causes of <br />elevated levels are unknown. As this well <br />has no integrity as a monitoring well of the <br />"B" seam, it will be abandoned from the <br />monitoring program in the next technical <br />revision submission. <br />Well SOM-129-H, the replacement for <br />sealed well SOM-127-H dropped thirty feet <br />during the 1995 WY. It is located relatively <br />close to areas mined, and the depths of <br />water in the well validate a low permeability <br />of the B Seam. <br />Full-suite chemical analyses were run on <br />wells SOM-C-72-H, SOM-129-H and JMB- <br />12. The source of water in a well SOM-C- <br />72-H is unknown. It is moderately alkaline, <br />saline sodium (TDS of 4380 mg/1) <br />bicarbonate water of low hardness. The <br />SOM-C-72-H sample acquired 9/3/95 <br />approaches the secondary drinking water <br />standard for ch]oride of 250 mg/1. The <br />9/3/95 sample exhibited dissolved iron <br />concentrations of 0.52 mg/I, and exceeded <br />the secondary drinking water standard in <br />groundwater of 0.3 mg/1. All other <br />parameters were well below groundwater <br />standards. <br />Well SOM-129-H is a slightly alkaline, <br />excessively saline (TDS averages 2641 mg/i) <br />sodium bicarbonate water of low hardness. <br />Concentrations of dissolved iron were less <br />18 REVISED f0l08196 <br />