How are water supply quality samples analyzed?

The samples are analyzed for Total Coliform Bacteria and Fecal Coliform Bacteria at a licensed laboratory. 

The testing method requires that filtered samples be incubated at certain temperatures. It takes between 48 and 72 hours to receive confirmation of the presence of Total Coliform bacteria. 

Presumptive results are available after 24 hours of incubation. Presumptive results are an indication that Total Coliform may be present. 

It takes an additional 24 hours to determine if Fecal Coliform is present and if it is not, it may take an additional 24 hours to confirm the presence of Total Coliform.

Show All Answers

1. Total Coliform and Fecal Coliform: what’s the difference?
2. Where are the water supply samples taken from?
3. How are water supply quality samples analyzed?
4. What happens if a sample tests positive for Total or Fecal Coliform?
5. What amount of Total Coliform indicates a water system violation?
6. What if Fecal Coliform is detected in a routine sample?