How the well often becomes impure and carries disease. A well near a barnyard or cesspool is likely to be unsafe for use. The liquids enter the soil, and sometimes follow along the crevice in rocks a hundred feet or more. Sewage, which is household waste, garbage, or dead animals cast into a stream, or placed near a well or spring, may cause many deaths among those using the water.
Alvin Davison The Human Body and Health (New York: American Book Company, 1909) 61