The high-volume, low-level radioactive liquid wastes originating at Oak Ridge National Laboratory are dispersed into the Tennessee River System by way of White Oak Creek and the Clinch River, Releases are controlled so that the resulting average concentration in the Clinch River complies with permissible levels set forth by the National Committee on Radiation Protection and the International Commission on Radiological Protection. Since 1951 measurements have been made of the radioactivity in the water and of the accumulation of radioactivity on the bottom sediment of the Clinch and Tennessee Rivers. Findings of the surveys on radioactivity on the bottom sediment are summarized for 1954 through 1958. (C.H.)