172 DOMESTIC WATER SUPPLIES FOR THE FARM 



a material improvement in odor and taste follows the application 

 of the treatment. The cost is slight and the process easily and 

 quickly applied, although a second treatment is sometimes re- 

 quired. With the possible exception of trout, fish are not likely 

 to be affected by copper sulphate in the amounts used in the 

 treatment. 



Bacteria. By far the greater part of the bacteria in water 

 are of a harmless nature. Nevertheless water frequently becomes 

 polluted with disease-producing bacteria, the removal of which is 

 imperative if the supply is to be used for drinking purposes. 



A treatment which has been applied with good results in many 

 instances consists in adding chloride or hypochlorite of lime to 

 the water. Both of these substances are powerful germicides, 

 and I part of the chemical to 7000 parts of water will destroy 

 practically all the bacteria present. 



In practice, one pound is commonly used to each 33,000 gal- 

 lons or 4500 cubic feet. It is dissolved and fed into the reservoir 

 as in the copper-sulphate treatment. If thoroughly disseminated, 

 it does its work within half an hour. The cost of the treatment 

 is very slight. 



The chief objection to the treatment lies in the fact that the 

 chlorine set free in the process remains in solution and gives a 

 very objectionable taste to the water. This, however, may be 

 removed by drawing the water through a thin layer of iron turn- 

 ings before use. 



