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• A = 103,500 ft2 (Dakota Coal at Cross Section A) <br />A = 36,000 ft2 (Dakota Coal at Cross Section A) <br />A = 298,479 ft2 (Underburden) <br />0 = 15,255 ft3/day (Overburden through flow discharge at Crass Section A) <br />0 = 46,816 ft3/day (Overburden through flow discharge at Cross Section B) <br />0 = 9,288 ft3/day (Overburden through flow discharge at Cross Section C) <br />0 = 492 ft3/day (Dakota coal through flow discharge at Cross Section A) <br />3 <br />0 = 171 ft /day (Dakota coal through flow discharge at Cross Sectiom B) <br />3 <br />0 = 4,133 ft /day (Underburden through flow discharge) <br />Drainage from storage in the overburden aquifer also contributes to the baseflow of <br />Calamity and Tuttle Draws. To determine discharge from storage the following drain <br />equation was used as described by Lohman (1972): <br />Os = 2s ST <br />'fr t <br />• where: <br />s = saturated thickness <br />S = storage coefficient <br />T = transmissivity <br />t = time <br />3 <br />0 = 1,521 ft /day (Discharge from storage at overburden Cross Section A) <br />0 = 3,796 ft3/day (Discharge from storage at overburden Cross Section B) <br />3 <br />0 = 382 ft /day (Discharge from storage at overburden Cross Section C) <br />ey adding the overburden aquifer through flow quantity with the quantity of water released <br />from storage (inflow) and comparing it with the respective stream baseflow (outflow) the <br />values should be similar. <br />Calculations of ground water flow (inflow) from the overburden, Dakota coal and <br />u nde rburden indicate that the aquifers are discharging 77,058 ft3/day, 663 ft3/day, and <br />4,133 ft3/day, respectively through the defined cross sections. Discharge from the Dakota <br />• coal and the under burden is relatively small compared to the overburden. As seen on <br />7-16 ~Revi sed 04/11/88 <br />