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monitoring, the need for further reclamation work, whether pollution of surface or subsurface water is <br />occurring, and the probability of future occurrence of such pollution. Impacts to ground water and surface <br />water are described below. <br />Ground Water Impacts <br />Ground Water Quantity-The pits at the Marr Mine would have disrupted the potentiometric surface in <br />an area that extends beyond the perimeters of the pits. Full recovery of the potentiometric surface can be <br />expected outside of the pits. Water table (unconfined) conditions would develop inside the backfilled pits. <br />Formation of significant surface spoil springs is not expected at the Marr Mine; therefore, there will be no <br />loss of ground water flows to surface waters. <br />Bedrock ground water-Ground water in overburden and the coal seam has been monitored for more <br />than 10 years in three wells that are located downgradient from the pits: 79-1, 79-2, and 79-3. Spoil <br />leachate has been monitored for more than 10 years in spoil well SP-01. Leachate from the spoil well is <br />an alkaline, sodium bicarbonate water with TDS consistently around 1300 mg/l. Chloride content has <br />always been less than 70 mg/l. Ground water from the three overburden wells is also an alkaline sodium <br />bicarbonate type of water, with TDS concentrations in the range 1100 - 4300 mg/l. The overburden <br />water contains significantly more chloride than the leachate, generally 200 - 2500 mg/l, compared to the <br />less than 70 mg/1 in the leachate. This difference in chloride content indicates spoil leachate has not <br />migrated to the overburden well locations. The overburden wells are inside the SL-04 bond release <br />areas; therefore, leachate has probably not migrated beyond these areas and it is unlikely adverse <br />impacts to bedrock ground systems have occurred inside or outside the SL-04 bond release areas. <br />Alluvial ground water-Alluvium within the area of influence of the mine is laterally discontinuous and <br />of limited areal extent (less than 300 acres in aggregate). The only water from the Marr Mine that could <br />reach the alluvium would be surface runoff. Spoil leachate is not likely to reach the alluvium because <br />significant spoil springs are not expected to form and the pits were not excavated in alluvium of <br />significant areal extent. The quality of surface runoff has been of a quality that is incapable of degrading <br />alluvial ground water, as indicated by more than 10 years discharges of surface runoff from pond F <br />where the discharges have been alkaline, with low TDS, TSS, and iron content. No mine impacts to <br />alluvial ground water have been found in 10 years of data from downgradient alluvial monitoring wells <br />at the main part of the mine (AO-2/AO-2A) or at the loadout(AP-1 and AP-2). <br />Ground Water Points of Compliance-DRMS previously concluded the Marr Mine does not have the <br />potential to negatively impact ground water quality and, therefore, a ground water point of compliance is <br />not warranted (Memo to DRMS Hydrology file, dated 6/13/07). The determination was based on the <br />mine pits' position on the west flank of the Johnny Moore syncline where water table (unconfined) <br />conditions exist inside the pits, resulting in a hydraulic gradient sloped toward the pits. The previous <br />discussion of ground water quality indicates the Marr Mine is in compliance with the Basic Standards for <br />Ground Water (CWQCC regulations 41.4 and 41.5). <br />Surface Water Impacts <br />The approved post-mining land use of the SL-04 bond release areas is rangeland. Based on historical <br />monitoring data at Marr's sediment control ponds, Marr's surface water can be expected to be alkaline and <br />Marr Mine SL4 13