• If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • Whenever you search in PBworks or on the Web, Dokkio Sidebar (from the makers of PBworks) will run the same search in your Drive, Dropbox, OneDrive, Gmail, Slack, and browsed web pages. Now you can find what you're looking for wherever it lives. Try Dokkio Sidebar for free.


Water Monitoring:  Coliform

Page history last edited by hoopman 8 years, 12 months ago

Frontpage > Water Monitoring > Step 2 > Coliform


Fecal coliform bacteria are found in the feces of human beings and other warm-blooded mammals, and birds. Fecal coliform by themselves are generally not pathogenic. Pathogenic organisms include bacteria, viruses and parasites that cause diseases and illnesses. Fecal coliform bacteria are already inside of you! They occur naturally in the human digestive tract and aid in the digestion of food. However, when a human being or other warm-blooded animal is infected, pathogenic organisms are found along with fecal coliform bacteria.   

If fecal coliform counts are high (over 200 colonies/100 ml of a water sample) in a river or lake, there is a greater chance that pathogenic organisms are also present. If you are swimming in waters with high levels of fecal coliform, you have a greater chance of developing a fever, nausea or stomach cramps from swallowing disease-causing organisms, or from pathogens entering the body through cuts in the skin, the nose, mouth, or ears. Some examples of diseases and illnesses that can be contracted in water with high fecal coliform counts include typhoid fever, hepatitis, gastroenteritis, dysentery and ear infections.


Why not test pathogens? Pathogens are relatively scarce in water, making it time-consuming and expensive to monitor them directly. Instead, we monitor fecal coliform because of the possible correlation between fecal coliform and the probability of contracting a disease from the water. 


Additional Resources

Backcountry Water Quality in Grand Teton National Park


Dog waste and Fecal coliform

Fecal coliform contamination in child day-care centers 

Contamination in water treatment facilities


N.C. Water: Safe to Drink? Clean Wells Left to Chance

Fecal Coliform testing: http://science.bigchalk.com/sciweb/science/do/document?set=search&lastset=search&groupid=1&requestid=lib_standard&resultid=6&sortResultsBy=TopicRelevance&groupResultsBy=&inmylist=false&edition=&ts=EC5ABE0B32368D508E54BCD6FA4367AC_1368199989862&urn=urn%3Abigchalk%3AUS%3BBCLib%3Bdocument%3B174915465&start=1














Water Quality 






What are Fecal Bacteria?


Sampling Procedure

  1. Remove the Stopper or cap just before sampling and avoid touching the inside of the bottle or cap.
  2. Plunge the sampling bottle under the water (opening downward), then turn the bottle underwater to face into the current and away from you.
  3. Avoid sampling the surface as coliform levels there are higher and not representative of the river.
  4. Avoid sampling from the bottom sediments for the same reason.
  5. Leave some space at the top of the container to allow mixing of sample before pipetting.


 Someday this will be a video of the pH test procedure, for now it is Slimey Jr.



Fecal Coliform Testing Procedure

  1. First, sanitize the foreceps by dipping foreceps in alcohol, then burning off with a flame (an alcohol lamp works well).  Do not place hot foreceps back into the alcohol.
  2. Using the sterilized foreceps, place the absorbent pad in the presterilized petri dish.  Be careful not to touch the pad with your fingers.
  3. Unscrew (or maybe break) the neck of the broth ampoule and drain the broth onto the pad.  The broth is liquid food for the coliform bacteria.  Put the top on the petri dish and set aside.
  4. Sanitize foreceps with alcohol and flame again.
  5. Unscrew the top half of the filtration system and place sterile filter paper on top of the filtration system's membrane with foreceps, grid side up.  Be sure that the filter lies completely flat with no wrinkles.
  6. Screw the top half of the filtration system to the top half.
  7. Before taking  a sample, use a pipette to rinse the filtration system with a small amount of distilled water.  Add the water through the hole at the top of the system.  (There should be three rubber stoppers at the top of the system and one hole without a stopper.
  8. Draw 5 mL of sample water into a pipette.  % mL is the suggested amount of river water to sample.  Too much water would result in too many colonies resulting in errors in making a proper count.
  9. Place the pipette into the open hole on top of the filtration system and release the water into the funnel.
  10. With the system level, use the suction pump and draw all of the sample through the filter while swirling so that the number of bacteria adhering to the upper filtration system is reduced.  Take care when pushing the syringe plunger back in to avoid pushing air back in to the filtration system and forcing the filter off the membrane.  Draw the water through the filter until it appears dry.
  11. Unscrew the top half of the funnel, and carefully remove the filter with the sanitized foreceps.
  12. Open the top of the petri dish, and slide the filter paper into the dish, grid side up.  The petri dish should be incubated within 30 minutes of filtering the sample; this will ensure heat-shock of any non-fecal coliform organisms.
  13. Seal the petri dish with waterproof tape and then enclose the petri dish in a water-tight bag.  Place in water bath for 24 hours at 44.5oC.  Petri dishes should be inverted to avoid condensation.  Wash your hands after this test.
  14. After incubation, carefully count the bacterial colonies on the filter using a magnifying glass or the unaided eye.  Each person in the group should take a turn counting to verify the bacterial count.  Each spot is counted as a colony.


 Someday this will be a video of the pH test procedure, for now it is Slimey Jr.


Data Sheet 

Fecal Coliform Data Sheet - Printable word doc.




Comments (0)

You don't have permission to comment on this page.