Studies to describe the survival of Escherichia coli were performed at two sites in a river. The one site was dominated by domestic discharge and the other by industrial inputs. E coli suspensions within membrane diffusion chambers were immersed in the river at the selected sites. An identical chamber was submerged in river water in the laboratory as a comparison. Two test runs were performed, one during winter (July) and one during summer (December). Samples to determine the survival of E coli was taken on a scheduled basis. Results obtained showed no significant difference between the survival pattern of E coli as determined during the summer and winter periods or in the different parts of the river. The same survival pattern was observed for the studies performed in the laboratory.