Rod-shaped bacteria usually found in the intestinal tracts of
animals, including humans. Their presence in water indicates
recent contamination by human or animal feces.
These bacteria are obviously not harmful to animals or humans,
but they do indicate that sewage contamination has occurred and
suggests the presence of disease-causing bacteria and viruses
such as E. Coli, salmonella, and cryptosporidium.
The presence of fecal coliform and fecal streptococcus bacteria
in water is affected by several environmental factors,
including sunlight, nutrient levels, temperature, amount and
character of sediment, predation by other organisms, flow, and
amount of runoff.