230 CONSERVATION OF GROUND WATER 



to get water out of the ground. The well-drilling industry can 

 now obtain large quantities of water from fine-textured 

 materials for which the only treatment years ago would have 

 been a sad shake of the head, and the water can be lifted 

 economically from depths which would once have been con- 

 sidered excessive. The overdevelopment of ground-water res- 

 ervoirs in many localities today would not have been possible 

 but for the successful development of pumps, casings, screens, 

 and new drilling techniques by the industry. Some might 

 argue that this very success must result in a decline in well 

 drilling because the industry, like whaling, is exhausting the 

 resource upon which it is dependent. Actually, however, only 

 a small proportion of the nation's important ground-water 

 reservoirs can be considered "overdeveloped" (see Plates II 

 and III), and the rest of the country still offers vast opportuni- 

 ties for ground-water development. In addition, the industry 

 can look ahead to another field of great promise, hardly ex- 

 plored as yet, in the use of wells for recharge of ground-water 

 reservoirs. 



For the development of a ground-water reservoir, involving 

 the interrelationships of many wells, a substantial volume of 

 technical research in a few areas has resulted in far better 

 understanding of the hydraulics of ground-water movement. 

 But the application of these principles to other ground-water 

 reservoirs must await the collection of essential basic hydro- 

 logic data. For an individual well a substantial amount of 

 hydrologic data may be obtained as drilling progresses, and 

 particularly where the well is to be one of several to serve the 

 needs of a single user, there is need for analysis of these data 

 to determine the relationships among the wells. Several pro- 

 gressive drilling contractors, private consultants, cities, and 

 industries have set up technical staffs to meet this need. 



Comprehensive analysis of the characteristics and potential 

 development of an entire ground-water reservoir has gener- 

 ally been by public investment, intended to provide funda- 

 mental data to all water users, and the task is usually per- 

 formed by hydrologists of Federal, state, or local governmen- 



