CHAPTER X. 

 TYPES OF WELLS. 



Types of Wells. Because of their cheapness, convenience 

 and fancied safety, wells are by far the most popular source of 

 domestic supplies in all regions in which water is found at reason- 

 able depth. 



The following tables show clearly and concisely the character- 

 istics and methods of sinking the common types adapted to un- 

 consolidated materials. 



Types of shallow wells and conditions to which they are adapted. 



Type of well. 



Description. 



Conditions to which well is best 

 adapted. 



Dug. 



Bored. 



Punched. 



Driven. 



Wells sunk by jet process. 



Generally circular excavations, 3 to 6 

 feet in diameter, dug or blasted by 

 hand and curbed with wood or with 

 stones or bricks laid without cement. 



Bored with various types of augers 

 from 2 inches to 3 feet in diameter, 

 rotated and lifted (together with the 

 earth) by hand or horsepower. 

 Curbed with wood, cement or tile 

 sections, with open or cemented 

 joints, and more rarely with iron tub- 

 ing. 



Small holes, usually under 6 inches in 

 diameter, sunk by hand or horse- 

 power, by dropping a steel cylinder 

 slit at the side so as to hold and lift 

 material by its spring. Clay is 

 added to incoherent materials like 

 sand to bind them together so that 

 they can be lifted. 



Small iron tubes, usually il to 4 inches 

 in diameter and provided with point 

 and screen, driven downward by 

 hand or by simple hand or horse- 

 power apparatus. 



Sunk by forcing water down small iron 

 " jet pipe " inside of casing, the water 

 rising between the two with the 

 drillings. Casing sinks by own 

 weight or is forced down by jacks or 

 otherwise. Diameter usually 2 to 4 

 inches. 



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Adapted to localities where the water is 

 near the surface, especially whereat 

 occurs as small seeps in clayey mate- 

 rials and requires extensive ' storage 

 space for its conservation. Should not 

 be near sources of pollution. 



Adapted to localities where the water is 

 at slight or medium depths and to 

 materials similar to those in which 

 open wells are sunk. 



Adapted to clayey materials in which 

 water occurs as seeps within So feet 

 of surface, but not at much greater 

 depths. 



Adapted to soft and fine materials, es- 

 pecially to sands and similar porous 

 materials carrying considerable water 

 at relatively slight depths. Particu- 

 larly desirable where upper soil car- 

 ries polluting matter. 



Adapted to soft materials capable of be- 

 ing readily broken up by the water 

 jet, especially to sands, etc., carrying 

 considerable water at relatively slight 

 depths. This method is an improve- 

 ment over driven wells, which are 

 adapted to same conditions, because 

 it affords samples of materials pene- 

 trated. Quick and fairly cheap and 

 especially useful in sinking large num- 

 bers of test wells in adjacent localities. 



