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Common Terms

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DISCLAIMER: The list of terms below is intended only as a courtesy. The intent is to describe the terms in a way to help people understand them in plain language. They are not legally binding definitions. Where possible, links to the legally binding definitions are provided.

Pathogen Indicator

Bacteria that predict the presence of harmful organisms associated with the fecal matter of warm-blooded animals. Indicator bacteria are not harmful, but where they are present, disease-causing germs are also likely to be present. Using an indicator is a simpler, more cost-effective way to test for harmful organisms than trying to identify and test for each potential pathogen individually.

Fecal coliform bacteria

A collection of relatively harmless microorganisms that occur in the intestines of warm-blooded animals, including humans. Although fecal coliform bacteria do not cause disease, they are an indicator that pathogens or disease-causing agents might be present. Thus, there is a potential health risk for individuals exposed to water with high concentrations of these bacteria.

Escherichia coli (E. coli)

The most common member of the fecal coliform bacteria group that is specific to the fecal material of warm-blooded animals, including humans. Like fecal coliform, it is an indicator that disease-causing agents may be present.


A type of bacteria usually found in the intestines of warm-blooded animals. Like fecal coliform and E. coli, Enterococcus is an indicator that disease-causing agents may be present in the water. Enterococcus is unique in that it can survive in salt water and is therefore typically used in beach monitoring efforts.


Inflammation of the stomach and intestines that results in vomiting or diarrhea. Headache, fever and abdominal cramps may also occur. Gastroenteritis can be caused by many different viruses and can last anywhere from 1 to 10 days. It is also know as the “stomach flu” although it is not related to the influenza virus.

Geometric mean

A type of average that is often used for highly skewed data. Unlike a traditional or arithmetic mean, a geometric mean tends to dampen the effect of very high or very low values that might bias the average if an arithmetic mean were used.

Designated Uses  

Those uses specified in water quality standards for each water body or segment whether or not they are being attained. Typical uses include public water supplies, propagation of fish and wildlife, recreation, agriculture, industry, or navigation. (Adapted from: Water Quality Standards Handbook: Second Edition. 1994. EPA 823-B-94-005a. Office of Water.)

Primary contact recreation

Any activity where the human body, particularly the head, is underwater including but not limited to swimming, water skiing, and diving (Also see DHEC Water Classifications and Standards, R. 61-68, 2008).

Secondary contact recreation

Any activity occurring on or near the water where the human body comes in contact with the water but is not submerged. This includes activities such as fishing, boating, canoeing, and wading (Also see DHEC Water Classifications and Standards, R. 61-68, 2008).