Bacteria are common in the environment and that includes well water, but generally they are not harmful. However some are and their presence in drinking water are classified into two groups, one verifying that the water is certainly contaminated with animal or human waste and the other indicating that this may also be the case, but it is not certain. The certain evidence of contamination is indicated by the presence of E. coli, which is also referred to as Faecal Coliform, the less important evidence is indicated by the presence of coliform bacteria in general and these are referred to as Total Coliforms.
E. coli or Faecal Coliform
The presence of this type of bacteria in the water confirms that the water is indeed contaminated with animal or human waste. Some microorganisms in this waste may cause only short-term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. Some severe strains are much more dangerous and may occasionally cause acute diarrhea that can lead on to kidney failure and death. Because E.coli are only present in animal and human waste and in very high numbers, they are definite proof that faecal contamination (animal or human waste) is present in the water.
Coliforms are a group of closely related bacteria, of which most are harmless; however, the presence of coliform bacteria in drinking water suggests that there may well be disease-causing microorganisms in the water. These coliforms are a broad class of bacteria which are found in the natural environment, but they also live in the digestive tracts of humans and many animals. The presence of coliform bacteria in tap water suggests that there may be a problem, because these bacteria are frequently found in locations similar to the kind of environment preferred by the type of bacteria that cause disease.
Although many types of coliform bacteria are harmless, their presence indicates that the water may be contaminated by animal or human waste and although E. coli may not be present in the water, the presence of Total Coliforms may well cause some health problems, which include diarrhea, cramps, nausea and vomiting, but at levels that are less serious for healthy people, but they can lead to more serious problems for people with a weakened immune systems, such as the very young and elderly.
To protect against bacteria Ultraviolet Sterilisers are used.