WATER SOLVENT ACTION OF WATER, ETC. 51 



open well and the chain and bucket should be discarded 

 and a pump with a closely fitting well cover which does 

 not leak, should be installed. Arrangements should be 

 made for the removal of waste water and to prevent the 

 seepage into the well of surface water. This can be accom- 

 plished, preferably, by the use of cement, or a brick and 

 mortar structure may be employed. In both cases the 

 foundation should be laid well below the surface of the 

 ground, as in Fig. 15, and upon this foundation the well 

 cover should be placed. The well which is to supply the 

 family with drinking water should not be located in the 



O 





Water-tight 

 Curb 



^Water-proofed 

 Portland Cement 





FIG. 15. Proposed method of protection of dug wells. 

 Bulletin 549, U. S. Dept. Agr.) 



(Farmers' 



barnyard or near any of the sources of possible infection 

 already mentioned in connection with spring water. No 

 drains or sewer pipes should run near the well for fear of 

 pollution, contamination, or possible infection with disease 

 organisms. 



(c) Deep Wells. Where practicable, artesian wells, Fig. 

 16, furnish our best source of water-supply. These wells 

 may vary in depth from one hundred to twenty-five hundred 

 feet. Where a flowing well can be obtained it will usually 

 prove to be the best and most economical water-supply. 



After having seen to it that the drinking water-supply is 

 as free as possible from infection, the factors that make for 



