Fecal Coliform Facts
Individually, fecal coliform bacteria are not necessarily harbingers of disease, but when found in large concentrations or colonies, they can be indicators of the presence of other disease causing microorganisms such as giardia or cryptosporidium.
The presence of fecal coliforms do indicate that there are mammal feces in the water and the more closely related the animal, the greater the chances are for infection if we come in contact with it either through ingestion or when swimming. Ingestion of other organisms who have accumulated the bacteria can also result in infection.
Fecal coliform counts may fluctuate in a given body of water, but they can actually settle out of a water column into the sediments on the bottom where the dark, moist conditions allow them to continue to multiply. When the sediments are stirred up, the bacteria reemerge and can contaminate the water.
Sources of E. Coli and fecal coliform bacteria: E. Coli is the most common form of fecal coliforms and although they are normally present in the digestive tract of humans and other mammals, contact with outside strains can lead to infection and serious illness. In addition to pet waste, sources include: faulty septic systems or waste treatment facilities, feed lots, manure storage areas, and feces from waterfowl and other wildlife.
The chart below outlines the varying densities, (number of colonies), per gram of feces for various animals including humans. Also shown is the mass generated per day by each.
Definitions:
- Coliform bacteria: a collection of microorganisms that live in colonies in the intestines of warm and cold-blooded organisms, including humans, that aid in the digestion of food
- Fecal coliform bacteria: a subgroup of coliform bacteria that are distinguished from others by their ability to grow at elevated temperatures and are associated only with fecal material of warm-blooded animals
- E. coli: Escherichia coli- The most common form of fecal coliforms; sources include feedlots, faulty septic systems, barnyards, pastures, rangelands, manure storage facilities, wildlife, waterfowl and pet feces.
- Federal Standard: the federal acceptable level of fecal coliform colonies above which water quality is said to be diminished; greater than 200 colony forming units (cfu) per 100 milliliters (mL) of water
