aee 



CONTENTS 



Introduction 1 



Scope of the study 4 



River basin characteristics 14 



Columbia River Basin 14 



Wenatchee River Basin 20 



Sources of pollution 20 



Water quality changes in a river 21 



Impoundmemt of water 21 



Return flows from irrigation 22 



Domestic sewage and industrial wastes 22 



Soil erosion 22 



Water quality effects on fish life 22 



Field sampling and analytical procedures 23 



Reliability of water quality data 25 



Hydrogen ion concentration (pH) 25 



Dissolved oxygen * 26 



Station 38, Columbia River below Vantage 26 



Ammonia and carbon dioxide 26 



Presentation of water quality data 26 



Analysis of data 91 



General discussion 91 



Columbia River at McNary Dam 91 



Snake River at mouth 91 



Columbia River at Pasco 92 



Yakima River at Enterprise 92 



Yakima River above Thorp 92 



Wenatchee River near mouth 92 



Crab Creek near mouth 92 



Columbia River below Vantage 93 



Columbia River at Rock Island Dam 93 



Nason Creek near mouth 93 



Chiwawa River near mouth 93 



Wenatchee River below Plain 93 



Wenatchee River in Tumwater Canyon 93 



Columbia River at Beebe Orchard Bridge 93 



Lake Wenatchee 94 



Water temperatures 94 



Water quality changes from upstream to downstream locations . . 102 



Water quality change, 1910-11 to 1954-57, Wenatchee River . . . 102 



Change in dissolved constituents between river stations .... Ill 



Effect of proposed impoundments on future water quality .... 112 



Summary 113 



Acknowledgments 114 



References 114 



111 



