CHAPTER XI. 



DUG WELLS. 



Advantages and Disadvantages of Dug Wells. Dug wells, 

 because of the ease with which they may be constructed by the 

 farmer himself when other work is not pressing, require little 

 money outlay and are therefore very popular. As commonly 

 sunk, however, they are the most dangerous of all sources of water, 

 but with certain precautions, discussed below, they may be made 

 to yield satisfactory supplies. 



The merits and drawbacks of this class of wells are concisely 

 summarized in the following table: 



Dug wells. 



Advantages. 



Disadvantages. 



Ease of construction; can be located, sunk and 



cased by owner. 

 Only hand power required. 

 No outfit required. 



No expensive materials required for curbing. 

 Cheapness in soft material. 



Ease of entrance of water. 



Utilization of all water strata. 

 Utilization of small seeps. 

 Quick response to rainfall. 



Large storage capacity. 

 Accessibility for cleaning. 



Limitation to soft materials; liability to caving while being 

 dug. 



Costliness in hard rock. 



Wood curbing often used affords favorable conditions for 



the development of bacteria. 

 Slight depth to which it can be sunk. 

 Ease of entrance of polluting matter through and over top 



of curb. 



Water, not being replenished, is often stagnant. 

 Fails frequently in time of drought. 

 Must usually be at distance from house and from barns, 



privies and cesspools to insure safety. 

 Necessity for frequent cleaning; danger from gas while 



cleaning. 



Short life when curbed with wood. 

 Ease of -entrance of animals and refuse through open top. 



Importance of Proper Location of Dug Wells. Upon the 

 proper location of the dug well, both the quantity and purity of 

 the water supply, in a large measure, depend. The chief con- 

 siderations in the location of open wells and wells in which pervious 

 casings are used, in the order of importance usually ascribed to 



them by the owners, are: Cost, accessibility, convenience and 



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