| OCR Text |
Show shown in Figure 21. Twenty years ago, the salt concentration was relatively uniform, as shown in Item 1 of Figure 21. With the completion of the causeway in 1959, the South Arm elevation is up to two feet higher than the North Arm. The North Arm salt concentration has increased from 21 percent to 25 percent while the shallow South Arm brines ( above 4175 foot elevation) contains only about 11 percent salt and deep South Arm brines contain 23 percent salt. The deep South Arm brines, which look and smell much like sewage, have been found unsuitable for commercial production of salt. The stratified condition has probably resulted from the two- directional flow of brine through the permeable causeway and through its two 15- foot culverts. Shallow south brines flow northward through the culverts while north brines flow southward at depth. One theory indicates that a condition of equilibrium will soon be reached. The South Arm shallow brines will remain at about ten percent salt while the deep south brines will remain the same in both salt concentration and volume. The North Arm brines will remain at 25 percent salt. This " equilibrium theory" is depicted by Item 2. Another theory, depicted in Item 3, states that, if the causeway remains unchanged, the shallow South Arm brines will decrease in salt concentration by one- half every eighteen years ( at constant Lake elevation) resulting in a concentration of only 2.5 percent by the year 2012. This " fresh water theory" also projects that the dense, deep south brines will increase in volume with little mixing occurring between the deep and the shallow brines. A third theory projects that dense and shallow layers of brine will form in both the South and the North Arms of the Lake. This " two- layer |
