Coliform bacteria serve an important purpose. While their presence is not necessarily dangerous, it may be indicative of the presence of bacteria which are. Coliform bacteria are used as a measuring stick to tell scientists and researchers whether or not fecal pathogens are present. They are easily identifiable and occur in large numbers which makes them easy to study. They also behave similarly to pathogens that may be found from the same source so they play an important part in discovering how pathogens will react in a given environment. Coliform bacteria occurs in water environments as well as soil and on vegetation. Areas with water runoff or those that are near sewage or septic systems commonly test the coliform bacteria in the water because these are likely spots for fecal bacteria which is often directly deposited in the water through human or animal waste.
One of the most common uses of coliform bacteria is to test the quality of water and check for the presence of pathogens or other bacteria. While most coliforms are harmless, fecal coliforms and their presence in water can be indicative of the presence of pathogens. Fecal coliforms are especially likely to be found where water might be stagnant or moving more slowly than usual. This could occur where water is pooling or getting backed up in a pipe or if it is puddling at the exit of a water line or if the water pressure is reduced. It is extremely important to the health of family members, employees or any residents of a location to have their water tested regularly using a sample of coliform bacteria in order to maintain confidence in the safety of the water. Because coliform bacteria comes from a fecal source, an intestinal illness can be cause for having water tested or if part of the water delivery system has been replaced or repaired.
E. coli is a fecal coliform and probably the most well known of pathogenic coliforms. Its presence almost always indicates water that has fecal contamination. Only a small number of strains of E. coli are harmful but the presence of any E.coli bacteria typically point to the presence of disease causing pathogens in the water. The presence of coliform bacterias can also indicate an occurrence of such diseases as typhoid, dysentery, cholera and giardiasis. Parasitic worms as well as viruses causing polio and hepatitis also tend to be found where coliforms are present. Although it is a simple matter to rid the water of the contamination by boiling it, it is important to regularly test water to insure safety and quality.
It is especially important for those obtaining their water supply from a well to have it regularly tested for coliforms, especially given that homes drawing their drinking water from a well are often located in a more rural area. This is likely to mean that a septic system is also present nearby and very likely farm animals. It is important to make sure that a septic system is sufficiently removed from the well water source and also to make sure that the well is deep enough and not left open to be contaminated by runoff or dead rodents falling in. Areas prone to flooding are also at a high risk for coliform contamination. Also remember that even if water is pure at the source it must still travel through your pipes to get to you and faulty plumbing can also result in contamination. Water from municipal sources contains chlorine, which kills off most bacteria that may come from pipes, but in setting where water is drawn from a well there is no chlorine present so it is of the utmost importance to regularly replace the water filter which should usually prevent any dangerous coliforms from making it through.
Nature presents us with an infinite number of dangerous pathogens but it also gives us many ways to protect ourselves and to detect these dangers. Most coliforms are totally harmless to humans and animals and actually provide us with a means to detect those strains of coliforms, which can be dangerous to humans and animals. As long as the proper precautions are taken, coliforms need not be feared.