TYPICAL ALKALI WATERS 



233 



like that of the upper San Luis Valley, Colorado, - - the 

 waters of which all contain larger or smaller quantities of 

 sodium carbonate, which permit of rough classification. 

 Irrigation well waters seldom change in composition as 

 do open streams because the water is not subject to the 

 various factors causing fluctuations. 



To show the seasonal fluctuations in the salt content of 

 rivers, analyses of the Salt and Gila Rivers of Arizona (8) 

 are given in Tables XXIII and XXIV. These are excep- 

 tional variations but illustrate how little a single analysis 

 might mean. The Sevier River, Utah, shows a somewhat 

 less fluctuation because not influenced by flood waters. 

 This is shown in Table XXV (33). 



Table XXIII. Seasonal Variation in Salt Content of Salt River, 

 Arizona, Expressed as Parts Salt per Million of Water 



Date 



(a) Aug. i-Sept. 1, 1899.. 



(b) Sept. 2-Sept. 9, 1899. 



(c) Sept. 10-Oct. 9, 1899. 



(d) Oct. 10-Oct. 17, 1899. 



(e) Oct. 18-Dec. 30, 1899. 



(f) Feb. 17-May 30, 1900 



(g) June i-Aug. 4, 1900. . 



Total 

 Salts 



724 

 1 100 

 1142 



952 

 1026 

 1069 

 1391 



Composition of the Waters 



Na 



122 

 183 



274 



309 

 327 

 407 



CI 



279 



315 



441 



409 

 437 

 594 



SO4 



979 

 481 

 727 



748 

 764 

 919 



CO3 



iS4 



802 



117 

 "5 

 131 



Ca 



679 

 102 



724 



402 

 437 

 651 



Mg 



174 

 233 

 279 



284 

 292 

 328 



K 



129 

 141 

 109 



153 

 123 

 112 



SiOs 



206 

 in 



583 



465 

 529 



355 



(a) High and low summer water. Average of four weekly composites 

 of samples taken daily. 



(b) Summer flood water. , One weekly composite of daily sample taken. 



(c) High and low summer waters. Average of four weekly composites 

 of daily samples. 



(d) Winter flood water. One composite of daily samples taken. 



(e) Low winter water. Average of ten weekly composites of daily 

 samples. 



(f) Low winter water. Average of thirteen weekly composites of daily 

 samples. 



(g) Very low summer water. Average of eight weekly composites of 

 daily samples. 



