For the first step in the process of testing the drinking water for bacteria, Brian Skaife a chemist/biologist at the Janesville Wasterwater Treatment Plant, pours a media purchased from Idexx called Colilert into a sample of drinking water collected from different parts of the city. At the Janesville Wastewater Treatment Plant, they test 72 samples per month, usually about 3-4 samples each day coming from different parts of the city. After adding the Colilert, the sample is incubated for 24 hours and then checked against a comparative example, which is yellow in color, to see if the sample tests positive for general bacteria. If the sample is yellow it means there is bacteria but not necessarily E.Coli, it is then checked under blacklight to see whether E.Coli is present among the bacteria. » Order a reprint of this photo
