Polluted Water Can Kill You 221 



Water-borne diseases include typhoid, paratyphoid, bacillary 

 dysentery, amoebic dysentery, cholera, and hemorrhagic jaundice, 

 but the potential pathogens found in water vary with the geographic 

 location. 



SOURCES OF WATER 



As moisture particles condense into droplets in the clouds, sheer 

 weight will eventually compel the water to fall toward the ground. 

 On the way to the earth's surface the rain picks up dirt and micro- 

 organisms suspended in the atmosphere. Toward the end of a 

 prolonged shower, however, the air may be free of microorganisms, 

 and this moisture reaches the earth devoid of living things. As 

 soon as the water strikes the ground, all kinds of microbes are 

 picked up and carried along in the water. Since open reservoirs 

 are exposed to contamination carried through the air and throvigh 

 ground washings, very few natural bodies of water can be relied 

 upon to yield a supply safe for human consumption. The magni- 

 tude of the problem increases with the population to be served. 



DUG WELLS 



Securing water in rural areas involves the construction of wells 

 of one type or another, with a simple dug well being the most 

 common. The depth of such wells varies with the locality, some 

 shallow ones being hardly more than ten or fifteen feet in depth. 

 Unless a person is aware of some of the pitfalls of shallow wells, 

 such a water supply can be the cause of serious family illnesses. 

 The surface organisms that might find their way into the water 

 supply are legion in both number and types. Nevertheless, a 

 carefully constructed well with proper walls and tight seals around 

 the top to prevent the entrance of soil-surface washings, can 

 serve as a reliable supply of safe water for a limited number of 

 individuals. During prolonged periods of drought, however, the 

 water table may recede and shallow wells are subject to running 

 dry. It pavs to dig deeper than one originally figures might 

 normally be required in order to provide a reserve water supplv. 



After arriving at the maximum anticipated needs, a well can 

 be dug wide enough and deep enough to provide the desired 



