Drinking water should be free of disease-causing organisms.  Coliform bacteria are organisms that are present in the environment and in the feces of all warm-blooded animals and humans. Therefore, water is analyzed for coliforms because their presence is an indication there may be disease-causing bacteria, parasites, and viruses in the water.

Types of water that may be tested include: drinking (potable) water, spa, swimming pool water, and reuse/reclaimed water.

Test Method 

  • The Colilert®-18 (IDEXX)
    Reference: Standards Methods for the Examination of Water and Wastewater, 9223B, an enzyme substrate test.  Colilert®-18 is a US EPA approved method.
  • Measurement uncertainty is available for Coliforms: Total and E.coli test upon request.

Turn Around Time

1-3 days

Test Code      

106 (presence-absence), 107 (quantitative)


See Coliforms (Total and E.coli) Sampling

Sample Transport

Coliform bacteria can grow rapidly in some water samples therefore the sample should be kept cold in transit.