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<br />I <br /> <br />I <br /> <br />A comparison of three Yellow Creek Dam possibilities is shown on slide <br />No.5. It has been assumed that a storage factor of two would be <br />sufficient for regulation, so that the capacity of Yellow Creek Dam <br />equitable to the 60,000 acre-feet system would be 138,000 acre-feet. <br />This dam would be 240 feet high with a crest length of 1,690 feet and <br />contain 5.8 million cubic yards. The resultant reservoir would have a <br />water surface elevation of 6,019 feet above sea level, and would cover <br />about 2,000 acres. <br /> <br />The possibility that the Yellow Creek system could be optimized through <br />sharing with other potential users on the White River has been seriously <br />contemplated. Preliminary negotiations have been held with the Yellow <br />Jacket Conservancy District, the Colorado River Water Conservation <br />District, the Bureau of Reclamation, and others. Depending on the <br />fruitfulness of these discussions, the eventual Yellow Creek Dam might <br />be as large as 428,000 acre-feet, which is the amount granted by our <br />conditional storage decree. <br /> <br />As I mentioned earlier, the de-watering and underground water utilization <br />program is an important phase of our planning. Early estimates by others <br />of the ground water yield from a system designed to de-water an open pit <br />capable of producing 50,000 barrels of oil per day from Tract C-a range <br />between 7 cfs, which is about 5,000 acre-feet per annum, to 85 cfs, <br />which is about 6l,000 acre-feet per annum. Studies based on our recent <br />pump tests and hydrological analyses indicate that the de-watering rate <br />required for a 50,000 barrel per day plant would be in the lower range <br />of these numbers. If the well system were expanded to include a ground <br />water development system of wells on tract, designed to yield as much <br />of the ground water in the vicinity of the tract as is reasonably <br />attainable, the water yield is anticipated to increase. <br /> <br />The quality of water encountered in the long term pump tests on tract <br />was found to average some 1,000 milligrams of total dissolved solids <br />per liter in the upper aquifer and about 2,500 milligrams of total <br />dissolved solids per liter in the lower aquifer. In holes to the north- <br />east of the tract, water ranging up to 22,000 milligrams of total dis- <br />solved solids per liter was encountered. Fortunately, a beneficial use <br />can be made of even this poor quality water, because it can be used for <br />moisturizing the spent shale prior to compaction. When utilized in this <br />fashion, there would be no return flow of this water to the surface <br />streams since it will be locked in to the shale pores. In the event <br />that small amounts might run off during flood stages, a small holding <br />pond will be provided near the tract to retain any saline water tempo- <br />rarily, either from surplus ground water production or from flood runoff. <br />This saline water will be recycled to the spent shale, either for evapo- <br />ration on the surface or for use in the compaction as mentioned before. <br /> <br />In view of these facts and the fact that ground water use is obviously <br />the most economical, we plan to utilize ground water to the maximum <br />practicable extent. In our view, it is good sound policy to use the <br />ground water resource to coincide with the development of the oil shale <br />resource, particularly that water which must be extracted to de-water <br />the mine. Nevertheless, uncertainties remain concerning quantities of <br /> <br />-49- <br />