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8 <br />of the existence of surface flows. <br />I The thickness of the blow sand overlying the Laramie is variable but <br />1 is sufficient to hold a large quantity of capillary water. This observa- <br />{~ tion, coupled with the small annual precipitation relative to the poten- <br />t /1 tial evapotranspiration, makes it unlikely that significant recharge to <br />the Laramie through the sand exists. This sand is not known to yield <br />water to wells except in conjunction with the stream deposits in Ennis <br />Draw. <br />Ground water exists in the coal seam of interest and in the over- <br />I <br />1~ <br />.Y <br />i <br />burden. The saturated thickness of the overburden is some 65 ft. Lateral <br />movement of this water is toward the northeast in the study area and <br />undoubtedly discharges into the sands and stream deposits in Ennis Draw <br />to the north and east of the project site. Ground water in neither the <br />coal yor overburden is known to provide a water supply for any purpose <br />in the study area. <br />III. Pre-Flining Subsurface Hydrology and Water Quality in Detailed Study <br />Site <br />A. Geology <br />A map of the study area is shown in Figure 3. The study site covers <br />about six square miles and includes Sections 25, 26, 35, and 36. The <br />land is gently sloping to the northeast toward Ennis Draw which is located <br />on the eastern boundary of the study area and generally runs in a north- <br />south direction. <br />A preliminary look at geophysical logs suggested that it would be <br /> <br />impractical to identify individual aquifers in the overburden sequence. <br />It was, therefore, decided to treat the coal, overburden and the over- <br />lying sand as individual potential aquifers. An east-west cross-section <br /> <br />