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Show QUALITY OF UNDERGROUND WATER. 33 to March, 1897, Salt Lake City was supplied with natural gas from this source, the total yield being approximately 150,000,000 cubic feet. But the supply finally became insufficient and the field was abandoned. Gas continues to be found in various parts of the valley and possibly other fields similar to that north of Salt Lake City may yet be found; but there is little reason for expecting much better results than already obtained and it is impossible to predict the localities where such supplies may be found. The water of Utah Lake represents the varied sources of its supply; part is derived directly from surface streams, another part from seepage, still another portion from springs, and the whole is concentrated by evaporation. The analysis by the Bureau of Soils on page 30 shows the present condition of the water. Sodium predominates, magnesium and calcium are subordinate, and the corresponding salts are principally sulphates and chlorides. Comparison with an analysis of Utah Lake by F. W\ Clarke twenty- one years earlier affords interesting data. a The total solids . have increased from 308 to 1,353 parts per million, and the character of the water has changed from a preponderating sulphate solution to one containing large amounts of chlorides; the sodium has increased remarkably and magnesium is now in excess of calcium. These changes appear to be mainly due to man's occupancy of the region. The streams have been diverted for irrigation and an increasing supply has reached the lake as seepage after passing through the alkaline soils of the lowlands. Evaporation in the shallow lake also has tended to concentrate its waters. The composition of the water of Great Salt Lake has been the subject of much investigation, and a list of the more important analyses is given on page 34. The lake receives the drainage of an enormous area, but by far the greater part of its supply is derived from the WTasatch Mountains, from Bear, Weber, and Jordan rivers. The mineral content of Great Salt Lake is the result of the concentration of a vast body of water during a long period of time, in which Lake Bonneville has given place by evaporation to the present lake. Great Salt Lake is shallow, and the seasonal and annual fluctuations in its level cause considerable differences in volume, with consequent changes in composition of the water. These changes are indicated by the increase of salinity from 13 per cent in 1873 to about 24 per cent in 1892. In August, 1892, the water of Great Salt Lake contained 238 parts per thousand of total solids, consisting of predominating sodium and smaller amounts of magnesium, potassium, and calcium, in the order named, the corresponding salts being chlorides and sulphates. The water of the lake is thus a concentrated brine, and in the winter months the point of saturation for sodium sulphate is actually reached and crystals of mirabilite & are deposited. The critical point for calcium carbonate is passed, so that, in spite of its abundance in the waters that supply the lake, none has been found in it. Apparently calcium carbonate is precipitated soon after entering the dense body of water. a Cameron, F. K., Jour. Am. Chem. Soe. vol. 37, 1905, p. 113. fcTalmage, J. E., " Great Salt Lake, Present and Past," 1900, p. 64. IRR 157- 06 3 |