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<br />resources f6rm perched groundwater aquifers which form in abandoned mine <br />• workings. It is also significant that dewatering flows which were <br />transferred to the surface water system at the Southfield mine normally meet <br />NPDES discharge effluent requirements. <br />In evaluating probable hydrologic consequences of the Southfield mining and <br />related operations on groundwater resources, overriding considerations <br />include the limited area and quantities of groundwater which will be effected <br />and the temporary nature of mining related impacts. Reductions in <br />groundwater flows, dewat~ring~of overlying mine workings, changes in <br />piezometric levels and alteration of groundwater flow patterns will be <br />addressed by natural mechanisms as the hydrologic system adjusts to <br />reestablish equilibrium. Shifts in groundwater chemistry and increases in <br />specific chemical constituents will be localized, with any changes declining <br />rapidly downgradient from the mine disturbance area as the natural effects of <br />mixing, dispersion, and dilution occur within the groundwater system. <br />Surface Water Consequences. Within the Southfield mine, loadout, and <br />• adjacent areas, surface drainage will flow to Newlin. Magpie, Second Alkali. <br />Oak and Chandler Creeks. As described in previous portions of this section <br />and in Section 2.04.7, Hydrology Description. with the exception of Oak Creek <br />these drainages have no year round base flow and are normally dry except when <br />flows occur as a result of springs snowmelt or major thunderstorm events. <br />With the exception of Magpie Creek, which was diverted by Dorchester in <br />conjunction with facility construction/installation and mine development. <br />none of the surface drainages will be directly disturbed or impacted by <br />mining and related operations. Due to flow limitations and upstream <br />diversions on both Newlin and Oak Creeks, there is no downstream surface <br />water use on any of the drainages within the immediate mine and loadout <br />areas. Downstream use does occur on Hardscrabble Creek, Coal Creek, and the <br />Arkansas River. However, as previously noted, lack of consistent base flows <br />and resulting dry streambed conditions limit the effective hydrologic <br />connection between the mine area and downstream drainages. <br />• <br />C:1TM19601VOL.2IREC.PLN <br />09/30/994:49pm Wp51/cmc 2.05.6.46 Revised - 9/30/94 <br />