other coastltuents have shown an increase. 

 Twelve million acre-feet of Impounded water 

 have been added to the Columbia River aui 

 Its tributaries above Pasco since I9IO. 



Columbia River at Maryhill and 

 Cascade Locks , Figures k^ and "^JB , 

 Table 1? : 



The 1910-11 data were obtained at 

 Cascade Locks ^ 60 miles downstream frcm 

 Maryhill, location of the 1952-53 sampling 

 8tati(»i. Between these two sampling sta- 

 tions, the Deschutes, Hood, Klickitat, 

 White Salmon, and Wind Rivers are tributary 

 to the Columbia River. The combined flow 

 frcn these tributaries is about 6 percent 

 of the Colimibla River flow. Since this is 

 a small percentage, the water quality of 

 the Columbia River at Maryhill will not 

 differ significantly from that at Cascade 

 Locks. These tributaries carry less dis- 

 solved material thsui does the Columbia 

 River at this location. 



The mean river discharge in the two 

 periods under comparison differed by less 

 than 4,000 c.f.s. All constituents in- 



creased excepting for silica and iron, 

 ■niese may have shown a decrease in the k2- 

 year period because of the precipitation 

 of collodlal silica and iron in the up- 

 stream reservoirs constructed subsequently 

 to 1910. Seme of the silica may have been 

 taken up In the cells of diatoms whose 

 abundance has been increased with the con- 

 struction of reservoirs. Seventeen mm ion 

 five hundred thouseuid acre -feet of im^pounded 

 water have been added to the Columbia River 

 above The Dalles since I910. 



Between the periods under comparison, 

 the upstream irrigated acreage increased by 

 76 percent, the upstream watershed popula- 

 tion by 6k percent and an industrial waste 

 population equivalent of 1,813,000 persons 

 was added. This increase in waste addition 

 and irrigation return flows resulted in the 

 following percentage increase in constitu- 

 ents (based on yearly weighted averages, 

 table 2k): Alkalinity - 52; hardness - kO; 

 dissolved solids - 32; sulfate - 70; calcium 

 plus magnesium - 33; sodium plus potassium 

 38; color - k^; chlorides - 52; and nitrate 

 - 80. Silica showed a 23 percent and Iron 

 a 50 percent decrease in the same 42-year 



Table 17. —Water quality comparison. 



Columbia River at Cascade Locks (60 miles below Karytill), 1911-12. 



In P.P.!?. 



Jan. 



Feb. 



Mar. April May Jung July Atig. 



S«pt. 



Oct. 



Hot. 



Deo. 



Tines Sampled 2333333 3 



Flow X 1,000 c.f.s. 81 110 82 l8l 372 522 305 



Total Alk. 63 51 61 US 39 Ui 51 



Total HardiMss 67 S3 60 SO U? U7 55 



Dissolved Sollda no 110 113 98 78 72 79 



Sulfate (SOj,) Ui 10 13 10 8 9 ID 



Silica 16 20 20 19 12 12 10 



Iron O.Oli 0.0k 0.05 0<,2li 0.11 0.10 0.06 



C« + Kg 23.9 18.U 21.3 17.9 17.6 17.U 20j» 



H« • 3A K 11.0 9.0 12.0 9oU 7.5 5.8 6.6 



Chlorld. (C1-) li.6 3.6 6.0 3.5 2.2 1.5 1.5 



Nitrate (HO3-) 0.35 0.56 0.55 O.I18 0.26 0.29 0.26 



Color 9 3U ID 27 13 10 5 



U 

 180 



61 



59 



91 



12 



11 

 0.0l» 



21.6 

 9.7 

 1.9 

 0.59 



10 



3 



129 

 59 



71 

 92 

 13 



10 

 Ojj 



2U.3 

 6.8 

 2.0 

 O.I1S 



3 

 85 

 61i 

 71 

 105 

 13 

 lit 



0.01 

 2U.7 



10.0 

 3.6 



0.50 



1 



3 



78 

 66 



73 

 lU 



lU 



12 

 0.02 



25.6 

 9.5 

 U.7 

 0.81 

 1 



3 

 70 

 6b 



68 

 111 



15 



li. 

 O.CQ. 



23.8 

 9.8 

 I1.I 

 0.S7 

 2 



Golmnbia River at Maryhill Ferrj' (60 miles above Cascade Lock) 

 19?2-S3 (U.S.G.S.) 



Tines Sanpledl 

 Plow X 1,000 c.f .a 

 Total AUt. 

 Total Hardness 

 Dissolved Solids 

 Sulfate (SOi,-) 

 Slllqa 

 Iron^ 

 Ca ♦ Mb 

 Ha ♦ 3A K 

 Chloride (CI") 

 Mltrate (NO--) 

 Color3 



3 



138 



78 



89 

 lli9 



17 



15 

 O.ID 



30.5 

 9.9 

 5.3 

 1.2 



22 



3 



156 



68 



7U 

 135 



H* 



11 

 0.1' 



25.8 

 9.0 

 1.0 

 0.9 



32 



3 

 252 

 62 

 63 

 133 

 D. 

 6.5 

 0.07 

 22.5 

 8.U 

 2.9 

 0.5 



22 



3 



510 



73 



6U 

 135 



111 

 7.5 

 0.03 



22.6 



13.U 

 2.8 



0.5 

 25 



3 



320 



66 



71 

 U6 



17 

 8.0 

 0.02 



25.1 

 5.8 

 2.2 

 0.3 

 7 



3 

 156 



80 



76 

 100 



20 

 8.6 

 O.OU 



26.7 



12.9 

 U,3 

 O.li 

 6 



3 



119 



75 



80 

 111 



26 



11 

 0.07 



28.2 



10.1 

 Ii.2 

 1.0 



5 



2 



86 

 86 

 95 

 92 

 27 

 U 



0, 

 33 

 13.1 



6.5 



0.9 



h 



02 



1 

 85 

 90 

 98 

 120 

 26 

 13 



0.02 

 Hi 

 lii.2 



6.9 



1.1 



h 



3 



81 



89 



99 

 118 



20 



16 

 0.02 



35 



12.6 

 6.1 

 X.h 



10 



1 U.S.O.S^, sanplesi each sample represents ccnposlte of 10 or more dally samples 



2 Flow at the Dalles, Oregon 



3 Taken fron 1951-52 D.S.O.S. Water Quality Data 



73 



