Potable water safety assessed by coliphage and bacterial tests

Abstract

Twenty samples of drinking water from five different distribution line sources in Lima, Peru, were tested for coliphage content. Bacteriological quality of these waters was assessed by a variety of techniques, Presence/Absence (P/A) test, H 2S paper strip test and total and fecal coliform MPN tests. In 47% of the samples, coliphage were the only indicator organisms present. The incidence of coliphage in these potable water supplies reflects the probability of human pathogenic virus also surviving the treatment process. In the bacteriological tests the P/A and H 2S paper strip techniques were found to be equally or more sensitive indicators of the presence of coliform/fecal coliform bacteria than the TC/FC MPN tests were.