Safe drinking water must not be contaminated with micro-organisms that cause disease. To prevent possible contamination, constant vigilance must be maintained to avoid the disastrous consequences which may befall a community with bad water.
Unsafe drinking water can spread a number of diseases – these diseases are known as WATERBORNE infections and include such illnesses as typhoid, cholera, and dysentery. All of these illnesses are intestinal disorders caused by microorganisms in the bodies of infected people and animals. Infected people and animals may not necessarily appear sick.
Microorganisms which do not cause disease are also found in the intestines. One group of these is called COLIFORM bacteria and is found in the lower intestinal tract of man and other warm-blooded animals. Coliforms alone do not cause disease. However, coliforms are easy to detect by bacteriological tests while other disease producing organisms are not. Millions of coliforms are expelled each time a person or animal defecates. So when coliform organisms are found in the water sample, they indicate that feces (bodily wastes) may have contaminated the water and that immediate action should be taken to find the source of contamination.