164 DOMESTIC WATER SUPPLIES FOR THE FARM 



less of the well, the waters should be at once looked upon with 

 suspicion. 



It is true that the roiliness or turbidity may result from a dis- 

 turbance of the soil at the very bottom of the well and be en- 

 tirely harmless; but, on the other hand, it may be an indication 

 of the entrance of polluted surface waters at the top. The cause 

 should, in any case, be investigated. 



The development of an unusual taste should likewise be looked 

 into at once. Often, especially in driven and other tubular wells, 

 the taste will be at once recognized as due to iron, and may be 

 dismissed from the mind as harmless. At other times a woody 

 taste is noticed. This may come from peaty matter in the soil 

 and be unavoidable, but if from wooden curbings, these should be 

 replaced by iron, stone or tile; for, although perhaps not always 

 absolutely unsafe, decaying wood in contact with the water is far 

 from desirable. 



The most dangerous pollution is that coming from the dis- 

 charges of man or animals, which seep through the ground from 

 the privy, cesspool or barnyard into the well. It is by such 

 pollution that the typhoid fever on the farm is frequently caused. 

 Sickness does not result from the use of polluted waters in every 

 instance, for the development of the more serious diseases requires 

 the transmission of the specific disease bacteria in addition to the 

 usual sewage bacteria accompanying filthy seepages. It is hardly 

 necessary to say that, even when specific disease germs are absent, 

 the use of polluted water, really a diluted form of sewage, is both 

 obnoxious and risky. 



Analyses and Bacteriological Examinations. When there is 

 any cause for suspecting pollution or for doubting the wholesome- 

 ness of a well water it is highly desirable that a sanitary examina- 

 tion of the water be made at once. 



Pollution in well waters is commonly indicated by the presence 

 of abnormal amounts of chlorine, usually derived from the urine 

 of animals, by the presence of organic matter in the state of 

 active decomposition, and by the presence of sewage bacteria. 



