78 THE FARM WATER SUPPLY 



Having been provided by nature with the best of ground 

 water, what kind does the average farm household use for 

 drinking and other domestic purposes? An examination of 

 many farms will show that the well has been located with 

 more regard for convenience than health. A common situa- 

 tion is within fifty feet of a sink-drain, a privy-vault, or a 

 barn-yard, and sometimes the well is surrounded by all three. 

 Usually a curb or embankment prevents any surface-wash from 

 entering the well ; but it does not appear to be borne in mind 

 that a large part of the rain-fall soaks into the earth, carrying 

 with it the soluble constituents of animal and kitchen wastes 

 with which it came in contact on the surface, sooner or later to 

 reach the well. 



The waters from such wells have almost always been found 

 to leave much larger amounts of solid residue than those from 

 unpolluted springs, and contain a higher proportion of chlor- 

 ine, because salt is abundant in all animal excretions and 

 kitchen slops. The waters are usually hard, since lime is also 

 an important constituent of animal wastes. High chlorine at 

 a distance from the ocean, may be considered in this state, a 

 sure indication of sewage pollution, and in most sections hard 

 water should be regarded with suspicion. The four forms of 

 nitrogen compounds in these waters give a larger aggregate 

 than in pure spring-waters, but the relative proportions of free 

 ammonia, albuminoid ammonia, nitrites and nitrates, vary widely 

 in diflerent samples. They all come from animal and vegetable 

 matter dissolved in the water, and show the stages of decompo- 

 sition which such matter has reached. These stages depend 

 upon the character of the soil and the amount of contamination. 



Free and albuminoid ammonias are usually high where the 

 soil either permits free pollution or hinders the oxidation of the 

 organic matter. Nitrates are high when the soil favors the 

 rapid oxidation of the organic matter. Consequently, waters 

 containing much free and albuminoid ammonia arising from 

 sewage, would be dangerous ; but if the nitrogen were present 

 only in the form of nitrates, the sewage would have been oxi- 

 dized to harmless mineral matter. Nitrites being an interme- 

 diate stage in the destruction of organic matter are looked upon 

 as suspicious constituents of water if not dangerous. 



