52 ILLINOIS ACADEMY OF SCIENCE 



To prevent the evils of stream pollution gaining too 

 great headway, central governmental control backed by in- 

 telligent public opinion is essential. The moulding of an 

 intelligent public opinion is, however, a rather difficult matter 

 for even among persons who have given considerable thought 

 to sanitary subjects, there exist gross misconceptions as to 

 the logical and practicable way to treat the problem of stream 

 pollution. There has been a tendency to permit sentimental- 

 ity to get the upper hand and this has resulted in giving wide 

 currency to some extravagant demands that are wholly im- 

 practicable. There is, however, a group of sanitary engin- 

 eers who have come into intimate contact with actual prob- 

 lems relating to the prevention of stream poUu'tion and among 

 these engineers there has gradually come about a unanimity 

 of opinion regarding certain essential factors relating to the 

 stream pollution problem. It will be the object of this paper 

 to present these opinions and the statements made will be 

 largely based upon recent careful inquiries among sanitary 

 engineers and others interested in sanitation. 



The subject may best be treated by first considering in 

 a broad way what the functions of a stream really are. Hav- 

 ing reached a satisfactory conclusion upon this point, it will 

 be possible to consider certain special uses of streams with 

 respect to stream pollution. 



General Functions of Streams. 



One extreme view of the functions of streams is that 

 they are provided by nature for conveying water to the popu- 

 lations that live upon their banks to be used freely for all 

 purposes for which water may be needed and that, therefore, 

 no one has a right to defile streams by discharging into them 

 impurities which may injure health, reduce the value of the 

 water in the stream for any purpose or add to the discomfort 

 of the water user at points lower down upon the stream. 

 Further, it is argued that common decency damands that a 

 community dispose of its excrementitious matter in some 

 other way than by passing it on to neighbors- 



The other extreme view is that streams are our natural 

 drainage courses and that they were provided by nature for 

 carrying ofif all the wastes of human activity and that to de- 

 prive persons of the right to so use streams is an injustice. 



In point of fact both of these views contain elements of 

 right, and yet both are wrong. The proper conception of a 

 stream recognizes the dual function of watering and draining 

 the country through which it passes. Some pollution of 

 streams is inevitable ; for with increased density of popula- 

 tion, increased cultivation of the soil and increased numbers 

 of urban communities it is practically impossible to prevent 



