Total Coliform Bacteria (Counts)

GENERAL INFORMATION
Coliforms are bacteria that are naturally present in the environment and are used as an indicator that other, potentially-harmful, bacteria may be present.

WELLS:  Levels of coliform over four (4) colonies can indicate poor well construction or cleaning, or issues related to aging of the well such as the presence of holes in in the well casing. Samples indicating the presence of coliform bacteria must be tested for E. coli.

HEALTH EFFECTS
See E. coli, fecal coliform, and fecal indicators.

Standard value 1: 
4.00
Standard units 1: 
MPN/100mL
Input units: 
CFU/100mL
MPN/100mL
Display name: 

Total Coliform Bacteria (Counts)

Contaminant group: 
Microbiological
Action is recommended 1: 

MCL ADVISORY - ACTION IS REQUIRED
Total coliform levels were detected in your water sample to exceed the maximum contaminant level (MCL) of 4 MPN or CFU as required for Private Water Systems without Continuous Disinfection.

Action is optional 1: 

ACTION IS OPTIONAL
Your well water meets compliance with the private water systems rules standard of <=4 MPN or CFU.

Major sources in drinking water: 
Naturally present in the environment
Treatment options: 

TREATMENT OPTIONS
Groundwater (underground drinking water) in a properly constructed well should have minimal-to-no coliform bacteria. If coliform are found in a well it generally means bacterial and mineral slimes have built up and your well needs to be professionally cleaned by a registered private water system contractor.

Homeowners who use cisterns, springs or ponds as a drinking water source should use treatment devices to disinfect and filter the water to remove coliform bacteria. The presence of total coliform in a water sample means the disinfection system is not working properly. Improperly maintained treatment devices can be sources of contamination. Home water filters and other water-treatment devices should be changed and maintained in accordance with manufacturer's recommendations.

For Water Wells Continuous disinfection may be installed on properly constructed private water wells. In Ohio continuous disinfection is not permitted to be installed on improperly constructed wells, or wells in poor, deteriorated condition. Improperly constructed wells or wells in poor condition with the inability to obtain acceptable levels of total coliform, fecal bacteria, or E. coli should be properly sealed.

Website resources: 

WEBSITE RESOURCES

Fact sheets: 

FACT SHEETS