Evaluation of drinking water treatment plant efficiency in microorganism removal by the coliphage, total coliform and H₂S paper strip tests

Two potable water quality monitoring tests, the H₂S paper strip test and coliphage test, were evaluated on Chilean raw potable source waters and drinking waters that had received conventional treatment to render them safe for drinking. Based on 108 samples in this study, it was found that the H₂S paper strip provided consumers with equivalent to, or greater protection than, the total coliform MPN test. In treated water, a highly significant relationship (P =<0.0001) between total coliforms and H₂S paper strip tests was observed. Significant relationships were also observed between total coliforms/coliphage and residual chlorine/H₂S paper strip test. These studies provide evidence that the H₂S paper strip test and the coliphage test are viable indicators of potable water quality and water treatment in two medium-sized cities in Chile.