SOURCES AND SAFETY OF UNDERGROUND SUPPLIES 47 



Atlanta, Ga., which finally had to be abandoned. For this reason 

 wells drilled in broken and jointed igneous rocks in cities and 

 other thickly populated regions are liable to pollution. Waters 

 from such wells, if they are to be used for drinking, should be 

 tested occasionally to determine whether they are polluted or 

 not. 



