what is coliform

Coliform bacteria are a large group of bacteria that occur throughout the environment. They are commonly found in soil, surface water, and on plants, and are present in the intestines of all warm-blooded animals and humans. Coliform bacteria are often referred to as "indicator organisms" because they indicate the potential presence of disease-causing bacteria in water. The presence of coliform bacteria in drinking water indicates that disease-causing organisms (pathogens) could be in the water system. Total coliform, fecal coliform, and E. coli are all indicators of drinking water quality. Fecal coliforms are types of total coliform that mostly exist in feces, and E. coli is a sub-group of fecal coliform. E. coli is considered to be the species of coliform bacteria that is the best indicator of fecal pollution and the possible presence of pathogens. While coliform bacteria are not normally causes of serious illness, their presence is used to infer that other pathogenic organisms of fecal origin may be present in a sample, or that said sample is not safe to consume.