COLIPHAGES AND BACTERIOPHAGES IN CANADIAN DRINKING WATERS

Eighteen samples of treated drinking water and their source waters in three Canadian cities were tested for coliphage, bacteriophage and bacterial content. In the source waters, bacterial concentrations varied from nondetectable to over 5,500 total coliforms per 100 mL, but they were all found to contain coliphage and bacteriophage. After treatment all the drinking waters were found to have residual total and free chlorine levels, to be negative for bacterial indicators, however, all contained coliphage and bacteriophage. Implications of these findings are discussed.