In this work the survival of C. jejuni, E. coli and K. pneumoniae in drinking water was studied. The research also studied how the indigenous microflora and the addition of a limiting nutrient, phosphorus, affects the survival. The last C. jejuni were isolated in culturable form after 8 days incubation at + 20 C without any differences between water treatments. Both E. coli strains and K. pneumoniae survived for several weeks. Coliform counts were significantly lower in waters where indigenous microflora was present. The addition of phoshorus enhanced slightly the survival of coliforms. Includes 7 references, figure.