THE IRRIGATION AGE. 



393 



DRILLING 30-INCH WELLS FOR IRRIGATION 



By F. W. PARK 



FIGURE 1. General view of the equipment used to drill 30-inch wells near Plainview, Tex. Only the lower part 

 of the derrick is shown. 



IRRIGATION by pumping is rapidly extending to 

 1 all parts of the United States. In many localities it 

 is feasible to pump from rivers or streams, or from 

 open pit wells, and, wherever conditions permit, these 

 sources of supply are usually more economical than 

 deep bored wells. There are, however, immense areas 

 in which water in sufficient quantity to irrigate is not 

 found on or near the surface but may be obtained 

 within practical pumping distance from deep bored 

 wells. In many of these wells, the water rises to 

 near the surface, so that the pumping lift is not great. 

 To a large number of present and prospective irriga- 

 tors, therefore, the most economical method of obtain- 

 ing a water supply from deep wells should be of in- 

 terest. 



The first consideration in a deep well water supply 

 is the type of pump that will be most reliable and 

 economical. The well should then be made to accom- 

 modate this type of pump. It should be remembered 

 that in irrigation by pumping the cost of pumping is 

 continuous and the well that is adapted for installing 

 the most economical type of pump is nearly always 

 the cheapest through the saving it effects in cost of 

 pumping. 



Trfere are three principal types of pumps used in 

 deep well pumping; the deep well plunger pump, the 

 air lift and the deep well turbine centrifugal pump. 



Deep well plunger pumps are now made with single 

 acting, double acting and triple acting water cylinders, 

 with two stroke cylinders and with two or more double 

 acting water cylinders mounted on a single line of 

 plunger rods. Some of these are very reliable and 

 economical for general purpose pumping, the best of 

 them having all bronze cylinders and bronze ball 

 valves. For irrigation pumping, wells are usually 

 pumped at or near capacity and the water nearly al- 

 ways contains a considerable amount of sand or grit 

 which will rapidly destroy the valves in any plunger 

 pump. For this reason plunger pumps are not gener- 

 ally considered desirable for irrigation pumping. 



The air lift will deliver more water from a deep 

 drilled well than any other type of pump but requires 

 a deeper well in which to operate and more power to 

 deliver a given quantity of water than any other pump. 

 The air lift requires three feet of submerged depth of 

 the air pipe for each foot of actual lift so that if the 

 actual lift to the surface is 100 feet the air pipe must 

 extend 400 feet in the well. Various manufacturers 

 claim comparatively high efficiencies for their air lift 

 pumping systems and many laboratory tests have been 

 made showing efficiencies of 25 to 33 per cent, but 

 tests made of actual installations at Waukesha, Wis., 

 in 1911 by the University of Wisconsin showed effi- 

 ciencies of only 16 to 18 per cent. It has been dem- 



