Bacterial and viral indicators

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Cultural methods can be used to determine concentrations of fecal indicators in environmental waters

• Total coliforms are bacteria found in animal intestines, in soils, on vegetation, and in industrial waters. They are used to assess drinking-water and groundwater quality.
• Escherichia coli (E. coli) is a coliform bacteria, is a natural inhabitant of the gastrointestinal tract of warm-blooded animals, and is direct evidence of fecal contamination.
• Enterococci bacteria are commonly present in the feces of warm-blooded animals. Enterococci are more persistent in water than coliforms and provide a different assessment of the transport of fecal contamination in groundwater than coliforms because of their different shape and survival rate.
• Coliphage are viral indicators that infect and replicate in coliform bacteria, primarily E. coli. Coliphage are found in high numbers in sewage and may be better than bacterial indicators to represent the survival and transport of viruses in the environment.