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• Professional Paper 708, Ground Water Hydraulics, by L. S. Lohman. <br />Transmissivity (T), storage coefficient (S), and coefficient of <br />permeability (K) are calculated on the attached graph. <br />From the data presented above, the recharge, storage and discharge <br />characteristics of the alluvial aquifer can be described. The alluvium <br />is recharged during high flow when the river level is higher than the <br />water table. Storage occurs in the interstices between particles, which <br />is approximately 20 percent of the volume in the alluvium. Discharge <br />from bank storage occurs during low flow when the gradient of the water <br />table draws water from the alluvium. This occurrence is demonstrated by <br />the water table contours and flow lines shown on the attached map, Flow <br />is from east to west, and using the product of permeability times the <br />area of discharge times water table gradient, the average flow rate is <br />2,2]6,000 gallons per day in winter months. <br />Groundwater chemistry is indicative of the source of water and the rock <br />• surrounding.it. The analyses of three samples collected on February 13, <br />1982 are given in the attached table. Water from the office well, taken <br />after 75 minutes of pumping, is probably recent snowmelt due to its <br />purity and low salinity. Samples taken from the two house wells near <br />the contact between the alluvium and the Mancox Shale show a significant <br />increase in salinity derived from weathering of the shale, which <br />underlies the alluvium. Drainage from hlesaverde Formation, which is <br />mainly sand and coal, would not contain the same level of salinity. <br />In summary, the surface facilities area rests on a cover of clayey <br />material over alluvial sand and gravel. The alluvium is highly <br />permeable and contains water from snowmelt and free river flow in winter <br />months. The river and alluvial water are mostly pure, except for <br />salinity derived from the underlying ~4ancos Shale. <br />• <br />