Water Testing for Growers: Guidelines on Which Test to Request

    Three different water tests are available at most labs:
  • Total coliform
  • Fecal coliform
  • The recommended generic E. coli test.*

*It is important to understand the difference and to request the generic E. coli test that is quantitative.

Total coliform bacteria are microbes found in the digestive systems of warm-blooded animals, in soil, on plants and in surface water. Fecal coliform bacteria are a kind of total coliform. The feces (or stool) and digestive systems of humans and warm-blooded animals contain millions of fecal coliforms. E. coli is part of the fecal coliform group and may be tested for by itself, such as with the recommended generic E. coli test.

Tests can indicate either a minimal reading of presence and/or absence or can quantify the amount of the pathogen’s presence. These quantitative tests are what you should be looking for with results measured in MPN (most probable number) or CFU (colony forming units). Additional information that might be helpful to know from the lab is: Water collection protocol, test results turnaround time and how test results are relayed to you.

Growers are encouraged to find local laboratories that can run the generic E. coli tests. Using the local phone book, look under “Water Testing.”