THE SANITARY EVALUATION OF PRIVATE 

 WATER SUPPLIES 



By Ralph L. France, Assistant Research Professor of Bacteriologjy. 



Introduction 



Water is a prime factor in the support of all forms of life. While not 

 classified as a food, yet it is a necessary item in the diet. The value 

 of an abundant and pure water supply has been known from remote times. 

 Hippocrates, some four hundred years before the beginning of the Chris- 

 tian era, wrote that a polluted water should be boiled and filtered before 

 it was used for drinking — certainly a most up-to-date piece of advice. 



Centers of population spranp: up around places where water was avail- 

 able. Where it was not available, extraordinary means were taken to 

 transport it. In Egypt and India today are to be found ruins of what 

 must have been great hydraulic works. Some were constructed at least 

 two thousand years before Christ. The great aqueducts of Rome were 

 built some few years before the Christian era. When one reflects that 

 these works of antiquity were constructed before the advent of steam, 

 electricity, and explosives, one is impressed with the great intelligence 

 and perseverance exhibited by these early engineers. 



The fact that water can intensify and spread certain diseases was sus- 

 pected long before the discoveries of Pasteur and the germ theory of 

 disease. As the knowledge of bacteriology and sanitation has been ad- 

 vanced by new discoveries, the number of epidemics caused by contam- 

 inated water has been gradually reduced. In spite of the present advanced 

 knowledge in sanitation and water works practice, some epidemics of 

 typhoid and dysentery still do occur. In most cases they can be traced 

 to a lack of alertness, or a lack of proper application of modern knowledge, 

 on the part of those responsible for the purity of the supply. 



It is the object of this bulletin to discuss rural private water supplies, 

 laying particular stress on the possibilities of their becoming contaminated 

 with disease producing bacteria; to explain the type of test used in the 

 laboratory to detect contamination; and to analyze the results of more 

 than 1,000 tests made during the past ten years on rural private water 

 supplies located in this State. 



Classification of Water 



"For practical purposes water may be classified as clean, polluted, or con- 

 taminatcd. (1) A clean water is one which at all times is free from contam- 

 ination or pollution, and safe for human consumption, as determined by 

 laboratory analysis, sanitary survey, and continued use. (2) A polluted water 

 is one which has suffered impairment of physical properties through the 

 addition of substances causing turbidity, color, odor, or taste. (3) A 

 contaminated water is one which carries potential infection by reason of the 

 addition of human or animal wastes, or has been rendered unwholesome 

 by poisonous chemical compounds." (Rosenau — Preventive Medicine and 

 Hygiene, 6th ed., 1935). 



