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Show CHAPTER II HISTORICAL DEVELOPMENT AND USE OF GREAT SALT LAKE Background Information In general, the historical development of Great Salt Lake ( Figure 1) has proceeded as a sequence of uncoordinated activities without an established overall management plan or strategy to maximize the total public benefit from the resources of the lake. Even so, the use of the resources of Great Salt Lake has played, and continues to play, an important role in the economic and social development of Utah. Extraction of salt from Great Salt Lake was established by the Mormon settlers soon after their arrival in Utah in 1847. They are responsible for pioneering the use of evaporation ponds for the removal of salt from the Great Salt Lake brine. The procedure which they used for recovering table salt ( sodium chloride), which is essentially the same process used today, consists of filling a pond with brine, allowing the brine to concentrate to a particular density where sodium chloride precipitates out, and then draining the rest of the brine from the pond. This process leaves a layer of almost pure sodium chloride in the bottom of the pond. The brine of Great Salt Lake contains a variety of other salts more valuable than sodium chloride. At present there are two companies, National Lead Industries, and Great Salt Lake Minerals and Chemicals Corporation, extracting minerals other than common salt from the lake. National Lead Industries plans to produce magnesium metal ( 45,000 tons/ year), liquified chlorine ( 81,000 tons/ year), and gypsum ( 48,000 tons/ year). Great Salt Lake Minerals and Chemical Corporation plans to produce magnesium chloride ( 300,000 tons/ year), potash ( potassium sulfate) ( 200,000 tons/ year), sodium sulfate ( 100,000 tons/ year), lithium chloride ( 5,000 tons/ year), and bromine ( 2,500 tons/ year). The lake contains additional salts of magnesium, sulfur, and potassium which may become economic to produce in the future. The completion of the Southern Pacific Transportation Company's causeway across Great Salt Lake in 1957 has resulted in a drastic change in the brine concentration characteristics of the lake. Since construction of the causeway, the brine in the northern arm of the lake has remained near saturation, while the brine south of the causeway is found to be less concentrated than before constructions. The main cause of this difference is that the southern end of the lake is fed by over 95 percent of the surface water inflow to the lake. The northern arm receives most of its inflow as brine from the southern end through the causeway. The major effect of this brine difference has been on the mineral extraction industries. The plants which intake brine from the northern arm of the lake receive brine which is already near saturation, while the plants receiving brine from the southern arm are fearful that the concentration of the brine will be diluted to a point where economic operations are not feasible. Whe- lan and Stauffer ( 1972) investigated the cost of equalizing brine concentration in the lake by: ( 1) removing 1,500 feet of fill and replacing it with a bridge or trestle; ( 2) pumping brine from the south arm to the north arm; or ( 3) removal of 65 feet of fill and diverting the Bear River to the north end. Alternately, freshening of the south arm could continue and a pipeline constructed to furnish brine from the northern arm to National Lead and the south arm salt companies. The importance of proper management of this resource is perhaps more fully appreciated when it is realized that the minerals contained in Great Salt Lake have an estimated value of over 90 billion dollars ( Searle, 1973). The exploration for oil in and around the north arm of Great Salt Lake has received attention atvarious times since the turn of the century. The presence of oil was established with the discovery of natural oil seeps at Rozel Point. Attempts to produce oil within the lake have resulted in only marginal success to the present time. Recent leases have been granted to Amoco and Wolfe for oil and gas exploration and drilling within the boundaries of Great Salt Lake. The effects this undertaking will have on other lake uses has not been established. The Dow Chemical Company ( 1973) prepared a report for the Division of Water Resources, Utah Department of Natural Resources, on the feasibility of locating an industrial complex in the Wasatch 5 |
