J 74 ILLINOIS STATE ACADEMY OF SCIENCE 



ment and growth of population have resulted in a load 

 of sewage or industrial waste that the streams can no 

 longer carry with due regard to public health or to the 

 use of the streams for stock on the farm". It is but 

 simple justice to say that several of these cities are 

 taking steps that may lead to the installation of disposal 

 plants. Decatur and Elgin are leading the way, and my 

 own city is agitating this question. One of the chief 

 difficulties is in getting the people to vote the necessary 

 funds. • 



In the 1923 report of the proceedings of the annual 

 meeting of the civil engineers of the State is found an 

 address by Paul Hansen who enumerates 103 disposal 

 plants, and makes the comment that many of the plants 

 are neglected, ten of them abandoned and eleven over- 

 loaded, disclosing that efficiency in many instances is far 

 from maintained. 



Thus is the run off from practically one-third of the 

 rainfall, expedited by tiling and sewers, seriously affect- 

 ed, and the citizens of our State are being deprived of 

 many billions of gallons of water annually. Cities are 

 finding it increasingly difficult to find a stream of suffic- 

 ient size to serve as a supply, when impounded, owing 

 to the unsanitary condition which may extend even to 

 the watershed. 



Judging from the reports at hand it is the common 

 practice of cities to create a reservoir on a' stream and 

 empty the sewage into the. stream at some point below 

 the reservoir. The next town below finds itself short of 

 water and becomes aware that the city above is using 

 the river for a sewer. But it builds its dam, and erects 

 an extensive purifying plant, expecting that chlorine and 

 other chemicals will protect the lives of the people, and 

 in turn conveys its sewage to a point below its dam, 

 thus contaminating the water for the next town below. 

 This goes on for the length of the stream. The health 

 of each of these places depends upon the efficacy of the 

 purification plant, and any imperfection in this that 

 causes raw water to get into the distributing system is 

 likely to result in serious epidemics. Some of our Illi- 

 nois cities have had sad experiences along this line. Pol- 



