Coliform Bacteria and Escherichia coli (E. Coli)


What are Coliform Bacteria and E. coli (i.e., fecal coliform indicator)?
Coliform bacteria are microorganisms (i.e., too small to be seen without a microscope) that originate in the intestinal tract of warm blooded animals and as organisms in soil and vegetation. Coliform bacteria that are often associated with human and animal fecal matter. Coliform bacteria are not necessarily disease producing themselves but can be indicators of organisms that cause adverse health effects. Escherichia coli (E. coli) are bacteria that live in the intestines of people and animals (i.e., fecal coliform indicator). The confirmed presence of E. Coli bacteria indicates that infectious microorganisms maybe in your water. Most strains of E. coli bacteria are harmless although certain strains cause illnesses. Drinking water sources can be contaminated by storm water run-off from roadways, farms and livestock operations, discharges from sewage treatment or septic systems. If total coliform bacteria are found, further testing is required to determine if the coliform bacteria are of fecal origin (e.g., Escherichia coli (E. coli)).

How are Coliform Bacteria tested?
A properly collected and preserved (with Sodium Thiosulfate) sample must be obtained. The “holding time” (i.e., time which Total Coliform must be analyzed after sample collection) is only 30 hours. The samples must be placed on ice or refrigerated (4 degrees Celsius +/- 2 degrees) shortly after sampling. There are a few NJDEP certified test methods for Coliform Bacteria, however only the presence/absence needs to be reported as an initial test procedure. Certain methods enumerate the colonies of bacteria found per 100 ml. of water. Basically, the bacteria are incubated in a prescribed media or reagent for 24 hours at 35° celsius. It is highly recommended to always repeat the positive Total Coliform analysis with an additional sample for confirmation.

What is the current Standard?
Total Coliform bacteria are classified as a “primary” standard and have a Maximum Contaminant Level (MCL) of zero (0) colonies/100ml.

What are the potential Health Effects with ingesting Coliform Bacteria in water?
Potential health effects include assorted gastroenteric infections and diseases. Symptoms such as nausea, vomiting, diarrhea, and stomach cramps are typically noticed. People with weakened immune symptoms are especially susceptible to illnesses. E. coli 0157:H7 strain has been isolated and determined to be a potential cause of deaths, usually as a result of a complication of the infection.

Should I continue to use my water if Coliform Bacteria are found above the MCL?
The answer is no for drinking water consumption. Boiling the water for at least one minute is a must before drinking.

What steps can I take to reduce Total Coliform levels in my water?
Short Term: purchase bottled water.
Long Term: 1.) Connect to public water 2.) Well replacement 3.) Disinfect the well with Chlorine 4.) Identification and removal of the source of contamination 5.) Repair the existing well 6.) Water Treatment with Chlorinators, or Ultraviolet Radiation, Membrane Filtration, and Reverse Osmosis. 7.) Contact your local Health Agency and a Water Treatment Professional.

If you install a water treatment system, be sure to conduct another test after the water has been treated to verify that the system is working effectively.

Where can I go for more information?
Your best help may be your local Health Agency. Also, go to the Helpful Links section of this website.

This information is meant to serve as a basic overview of the material discussed. Always obtain professional advice prior to implementing a plan of action.