individual analyses over a period of a year. 

 The concentration of a dissolved constituent 

 is not inversely proportional to flow on a 

 direct basis. During high-flow periods, the 

 concentration of a constituent per unit 

 volume of flow is less than during low-flow 

 periods . 



Perhaps a better method of constituent 

 comparison between time periods could be 

 made on the basis of annual pounds dis- 

 charged, providing there was not a great 

 difference in the yearly discharge between 

 the time periods. Since the mean annual 

 flows in these two periods under comparison 

 are close, table 32 has been prepared to 

 show the constituents discharged during 

 these two periods in 10-^ tons per year. On 

 this basis, the percent increase in constit- 

 uents between 1910-11 and 1954-57 was: 

 Total alkalinity 46; calcium plus magnesium 

 54; sodium plus potasfium 29; total solids 

 48; and total hardness 39 percent. Iron 

 values were substantially the same while 

 sulfate decreased 70 percent. This compari- 

 son method gives higher-percentage increases 

 for most of the constituents. 



In summary, the activities of man in 

 the Wenatchee River Basin between 1910-11 

 and 1954-57 has increased the dissolved 

 constituents in the river, on am overall 



basis, of about 40 percent and the color 

 and turbidity have perhaps doubled. 



CHANGE IN DISSOLVED CONSTITUENTS 

 BETWEEN RIVER STATIONS 



The specific conductance of a natural 

 water indicates the total concentration of 

 the ionized constituents and it usually 

 correlates closely with the dissolved solids 

 or residue in the water. Determinations 

 for specific conductance are rapid, precise 

 and the sample is not consumed or altered. 

 Table 33 gives the average ratio (of a 

 large number of individual determinations) 

 between dissolved solids sind specific con- 

 ductance for stream stations in the survey 

 area. Values shown for the Wenatchee River 

 are subject to error (solids values too 

 high) since they were computed on the basis 

 of total and not dissolved solids. (Uni- 

 versity of Washington quality tests were 

 made for total solids and not for dissolved 

 and suspended solids.) 



Since individual specific conductance 

 values are subject to less error than are 

 individual solids determination, the ratios 

 of dissolved solids to specific conductance 

 from table 33 were used with specific con- 

 ductance values from tables 6 to 21 to get 



Table 33. — Ratio of dissolved solids to specific conductance — 



1/ 



Stream 



Columbia River at Grand Coulee 



Columbia River at Maryhill Ferry 



Yakima River at Cle Elum 



Yakima River at Kiona 



Snake River at Central Ferry 



Snake River at Kings Hill 



Wenatchee River at Lake Wenatchee — 



2/ 



Wenatchee River near Wenatchee — ■ 



2/ 



\/ Using U.S.G.S. data for yearly-weighted-average values. 



2/ Using University of Washington data with total solids 

 where turbidity was less than 10. 



Ill 



