HOW LOCAL SUPPLIES ARE USED 211 



In larger houses where more water is used the difficulty in 

 pumping is the chief obstacle to the continued use of well water, 

 and it is this difficulty which is often the determining factor in 

 securing the introduction of water from the public works. The 

 convenience of having the water in the pipes under pressure 

 more than compensates for the rates that are collected. On the 

 other hand, in recent years improvements in small automatic 

 electrically driven pumps, with the general presence of electric 

 current at moderate rates available for driving them, have made 

 it possible to continue the use of well waters in many large 

 houses in outlying or suburban districts where the ground 

 water is of good sanitary quality. 



With industrial establishments the cost of pumping is often 

 of controlling importance. If a separate pumping station has 

 to be maintained and additional men must be employed to 

 operate it, the operating cost will be considerable and will 

 not be warranted unless the consumption of water is rather 

 large. Most industrial establishments, however, have steam 

 plants always in service. When the pumping can be done in 

 the establishment, the pump being located in some convenient 

 corner and looked after by men otherwise employed, the cost 

 of pumping is low relatively, and if a supply of local water is 

 readily available it may pay to pump it, even though the quan- 

 tities used are not very great. 



The cost at which water from the public works is supplied 

 is an important element in determining the extent of use of 

 local supplies. If water from the public works is from a nearby 

 lake, and is supplied at a very low cost per thousand gallons, 

 there is less inducement to use local supplies. If, on the other 

 hand, the water of the public supply is brought from costly 

 impounding reservoirs at a great distance, and necessarily costs 

 much more per thousand gallons, there is inducement to con- 

 tinue and extend the use of local sources of supply. 



Amount of Local Supplies. Exact statistics are difficult to 

 secure. It was estimated many years ago that at Berlin, Germany, 

 the use of water from local sources, that is, from wells in the 

 gravel under the city, exceeded the output of the public works. 



