2* The main stem oxygen block appears to be a distinct 

 entity quite unrelated to the pollutional loading of the major 

 tributaries. Vftiatever pollutional overloading; received by the 

 major tributaries apparently is quite well stabilized before it 

 reaches the main Willamette. 



3. To the extent that data obtained by spot sampling provide 

 a representative base for calculations, it may be concluded that an 

 overall reduction exceeding fifty percent of the 1949 oxygen-consuming 

 waste loading of the main stem Willamette must be effected to maintain 

 a minimum dissolved oxygen concentration of five parts per million 

 throughout the river. As the primary treatment of domestic sewage will 

 not provide the degree of pollution abatement required, the use of the 

 Willamette River by fall-ohinook salmon must await sufficiently increased 

 minimum river flows that may be provided by the Corps of Engineers* 

 Willamette Valley Project and/or the effective treatment of a signifi- 

 cant fraction of the oxygen- consuming industrial wastes. 



4. Available data will not permit more than an extremely gross 

 prediction of the minimum degree of pollution abatement required to 

 eliminate the oxygen block of the lower Willamette, This point is of 

 considerable interest to the communities end industries of the Willamette 

 Valley for, presumably, neither are anxious to finance a greater degree 

 of pollution abatement than conditions warrant. A detailed study of the 

 sources, magnitude, and subsequent effects of the pollution loading of 

 the river, coordinated with that of the absorption capacity of many 

 reaches of the river under varying conditions of flows and temperatures 

 is a prerequisite to any accurate analysis of the Willamette pollution 

 problem and its effective and most economical solution. 



LITERATUHE CITED 



1946. Craig, J. A., and L. D. Townsend. An Investigation of 

 Fish-Maintenance Problems in Relation to the Willamette 

 Valley Project. U. S. Fish and Wildlife Service, Washington, 

 D, C», Special Scientific Report Number 33, 78 pages. (Mimeo- 

 graphed) • 



1945. Dimick, R, E., and Fred Merryfield. The fishes of the Willamette 

 River System in Relation to Pollution. Oregon State College, 

 Engineering Experiment Station, Corvallis, Oregon, Bulletin 20, 

 58 pages. 



1950» Fish, Frederic F., and Robert R. Rucker. Pollution in the 

 Lower Columbia River Basin in 1948-with Particular Reference 

 to the Willamette Basin. U» S. Fish and Wildlife Service, 

 Washington, D. C, Special Scientific Report - Fisheries 

 Number 30, 22 pages. (Mimeographed). 



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