There are many types of bacteria on earth, but not all pose a health threat to animals and humans. Some consume organic debris or produce byproducts that kill some pathogens. Total Coliform bacteria are a group of closely related species that are generally not harmful; therefore they have been selected as an indicator of other harmful biological organisms in drinking water for two main reasons. First, if total coliform bacteria are found in a water sample, it indicates surface contamination (from construction or recent repairs) has reached the water and disease causing organisms may be present. Second, total coliform bacteria can be killed by disinfection, meaning chlorination or boiling of the water.

If an infant is living in the home

If you have recently installed a new well, pump. or pipes

If family members have reoccurring gastrointestinal illnesses

If you are buying a new home with a private water supply

If there is a change in odor, taste, or appearance of your water

Human and animal waste (feedlots, pets, septic systems)

Seepage or discharge from septic tanks, sewage treatment facilities, and natural soil and plant bacteria

Insects, rodents, or other animals entering well

Flood waters or suface runoff

Any system with casing or caps that are not water-tight

Fecal Coliform and Eschericha coli bacteria (found in greater amounts in animal fecal matter than total coliform) can cause diarrhea, vomiting, typhoid fever, dysentery, salmonellosis, hepatitis, cholera, possibly jaundice, headaches, and fatigue. A positive total coliform result could indicate the presence of these bacteria.

If a present or “unsafe” result is returned to you, the water should not be used unless it is boiled for one minute, the water source is disinfected with chlorine (well owner or licensed well driller or pump installer can do this), filtration, ultraviolet irradiation, ozonating, silver treatment, iodination, or pasteurization is completed, or buy bottled water.

• https://water.unl.edu/article/drinking-water-wells/total-coliform-bacteria-drinking-water
• https://www.health.state.mn.us/communities/environment/water/wells/waterquality/bacteria.html
• https://www.health.state.mn.us/communities/environment/water/factsheet/coliform.html