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-24- <br />2 <br />Salt Loading <br />Sediment and flow control facilities such as sediment ponds and <br />diversion ditches which detain water will have the effect of increasing <br />the concentration of total dissolved solids in the water due to <br />evaporation. Hlso, any water pumped from the pits into surface <br />drainages to facilitate operations may contain relatively high levels of <br />dissolved salts. While this is difficult to quantify, the result nay be <br />to increase dissolved salt levels in streams draining the mine property. <br />Using data from Williams Uraw, the Division has made the following <br />estimate: <br />The average salt discharge of 172.3 grams per day tunes 62 <br />days gives an assumed annual salt discharge of 10.7 kilograms <br />per year from the Kerr mine plan area within Williams Draw. <br />Considering the respective amount of disturbed area tributary to <br />each of Bolton, Bush, Williams, Sudduth and Mann Draws, the total <br />amount of salt loading on receiving streams is estimated to be <br />about 78.7 kilograms per year. <br />This can be broken down into the amount of loading on each <br />individual stream: <br />Bolton Draw 9U.5 kilograms/yr. <br />Bush Draw 3.9 kg/yr <br />Williams Draw 10.7 kg/yr <br />Sudduth Draw 2.7 kg/yr <br />Mann Draw 16.1 Kg/yr <br />Canadian River 123.9 kg/yr <br />After reclamation is completed and the sediment ponds are removed, <br />salt loading should drop to natural levels. <br />3. Change in surface water ion balance <br />Data collected by the Kerr Coal Company indicates a change from a <br />calcium-bicarbonate type baseline water to a sodium-bicarbonate and <br />magnesium-sulfate type affected water. These changes, along with <br />the anticipated salt loading, could cause the water quality to be <br />somewhat less suitable for stock water or irrigation. SAR values <br />would be increased. <br />None of these changes, including salt loading, would be significant <br />enough to affect surface water usage. Surface water quality would <br />still be well below recommended stock water standards for total <br />dissolved solids (7000 mg/1). Affected surface waters, like the <br />baseline waters, would classify as medium salinity, low alkali <br />hazard irrigation waters. <br />Surface water chemistry should return to baseline conditions after <br />pH dewatering has ceased, the pits have been backfilled, graded, <br />and topsoiled, and sediment ponds are removed. <br />