EFFECTS OF DOMESTIC SEWAGE 



Self -Purification of Streams 



It will aid in our understanding of the general problem if brief 

 consideration is given to the effect of domestic sewage, and particu- 

 larly to the purification of streams polluted with it. One sees the 

 process carried out so commonly and often so rapidly and so well 

 that one does not stop to wonder what becomes of all the sewage 

 which day and night is being discharged into our streams from the 

 rapidly increasing city population of this country. The time was 

 for more than a century that Troy poured its sewage into the 

 Hudson river while Albany only six miles away drew from the 

 stream its drinking water, and indeed found it bright and clear and 

 unobjectionable. To consider it merely a matter of dilution is to 

 overlook the real condition. The material had been actually changed 

 and not merely diluted, so there was no sewage in the river when the 

 water reached Albany. But little by little the zone of pollution 

 extended down stream until sight and smell no less than scientific 

 study warned against the practice. The circumstances have repeated 

 themselves a score of times or more in the course of this same 

 stream, until now the noble river, that once ran unsullied from the 

 mountains to the sea, shows little of its former purity and has lost 

 much of its value to the state, if, indeed, it is not in some ways an 

 actual menace to the welfare of the region adjacent to it. 



The two questions suggested for our consideration are equally 

 interesting and important. First, how does the river get rid of the 

 human wastes turned into its waters and become again pure and 

 healthful; and, secondly, why does the process fail later, or what 

 causes the loss of the power of self purification manifested at an 

 earlier date? Pollution and purification are evidently antagonistic 

 processes; under circumstances either may become master of the 

 situation, and it behooves man to know what factors control the 

 results, that he may aid the one process or restrain the other. The 

 application of this knowledge to the Hudson in earlier times would 

 evidently have retained this stream in its original purity and wealth 

 of aquatic life, while adequate, intelligent treatment of the situation 

 may even now restore the stream to its pristine condition. C E. 

 Turner has recently made an intensive study for two years of the 



