CHAPTER XIV 

 WATER SUPPLY AND SEWAGE DISPOSAL 1 



171. Sources of water supply. One of the most important 

 problems confronting the people of cities is the matter of 

 proper water supply. It is an important problem because the 

 health of the people is to a great extent dependent upon it. 

 There must be enough water to serve the purpose of cleanli- 

 ness and for drinking and other uses, and its quality must be 

 such that it may be used without danger. One of the most 

 serious afflictions that.can befall a city is scarcity of water in 

 the hot summer weather. 



To find a suitable supply for a city is not easy. In the 

 country or small villages dependence is placed upon wells or 

 occasionally upon springs. In a city this source is not prac- 

 ticable. It would be extremely difficult to secure from wells 

 a supply sufficient for a large city, and furthermore the soil 

 in cities becomes so filled with various waste materials that 

 the waters from surface wells would hardly be suitable for 

 use. The only other available sources of supply in most cases 

 are lakes or rivers. A great many American towns pump their 

 water from rivers. We shall see later some of the objections 

 to this source of supply. 



The waters of large lakes are among the purest we have, 

 provided only that impurities are not introduced into them 

 from the shore. 



172. Importance of pure water. The importance of pure 

 water lies very largely in its relation to disease. We have 

 learned that many sorts of bacteria are commonly found in 

 water, and that no water is entirely free from them unless it 



1 See footnote at beginning of Chapter XIII. 

 154 



