U.K.-based IDEXX’s Colilert®-18/Quanti-Tray® test method is accepted for compliance testing in the United Kingdom by the DWI and approved for compliance testing in the United States, Germany, Hungary and Norway. The method detects and enumerates total coliforms and E. coli simultaneously. It produces confirmed results in 18 hours. Simply add the reagent to a water sample, pour the mixture into the tray and incubate for 18 hours. The test is accurate to 1 organism/100 ml.