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i? <br />? ? <br />?}Spoil springs will be present at both reclaimed mine areas which discharge the ma?arity of the spoil <br />water to the surface. This is an impact since no span springs existed in the premine condition, <br />C} Vince the pyrite and easily dissolved salts are washed out of the span, TDS in bath spoil springs will <br />gradually get lower until some time many years from now.. Eventually, the spoil spring water quality will <br />get better than the overburden quality. At a time much mare distant in the future and much snore difficult <br />to calculate, the span water will approach xnri.gation water quality. Time periods for this to occur are given <br />later in this section. <br />The TDS of the Np'DES D?}i discharge at the New Horizon #11'?ine fluctuates inversely in response to <br />flows during irrigation season. The overburden wells and Spoil Spring #1 fluctuate to a lesser extent. <br />S flip Water I?n iZtration rota haw-wa?? <br />water infiltration will buildup in the spoil downgradient and begin to seep into the law-wall, This spoil <br />water may enter one or more of the minor sandstone beds of the overburden Dakota Sandstone}. This <br />annual infiltration is calculated. below, assuming a 1d" thick somewhat permeable bed in the law-wall <br />strata: <br />Seepage into low-wall for the New Horizon #? I'?ine = ?l?" ft. thick permeable sandstone bed in low <br />wall}?B?OO' ft. wide seepage area}?o.l? ft. per day seepage velocity}?1.143,5ba cu. ft, to ac, ft.}?3?5 days <br />per year} ^ 7? ac.ft per year. <br />The seepage velocity could be as high as o.3 feet per day, depending upon the sandstone permeability. <br />using a worst case of ?.3 feetlday, this results in a travel of ia00 feet every ?? years. <br />?t is strongly believed that spoil water seepage into the low-wall will not have any significant impact on <br />water quality, flaw rates, well usage etc. dine to four reasons: <br />?} As described in this section, the water duality of the spoil water will be at a maximum ?% to l.t?%o <br />higher in TDS than the existing overburden water quality, which is relatively poor. Therefore,. regardless <br />of the seepage rates into the sandstone zones; the water duality will be very similar to what has been <br />consistently tested in the overburden, with a TDS from 2.8a? to 350 ppm. <br />?) Due to the low seepage rates, the movement is very slow ? l+??a feet every 10 years}. <br />3}The sandstones above the Dakota coals have historically been poor in quality and too low in flow rates <br />to provide useful wells. Apparently, for this reason, na known wells in the vicinity of the mine area have <br />been completed in the Dakota sandstone. ft is very unlikely that any new wells will be completed in the <br />Dakota sandstone in the vicinity since the Burro Canyon Formation provides significantly better water <br />duality and flow and is located only 5o to i0(1 feet deeper than the Dakota sandstone. <br />4} The local wells are completed in the Burro Canyon Formation, which is below the Dakota coals.. <br />Although this zone has significantly better quality water, these sandstones are separated from the spoil <br />by shale layers with very law permeability, therefore these aquifers should not be affected by the spoil <br />water.