Abstract: Reaeration coefficients of the North Fork Licking River at Utica, Ohio were measured by the radioactive-tracer method. The tests were conducted on a 2.1-mile reach on September 23 and October 7, 1981, during low-flow conditions. Krypton-85 gas and tritium were the radioactive tracers, which were used in conjunction with rhodamine-WT dye. The reaeration coefficients determined on September 23 were 3.09 days^-1 (subreach 1-2) and 3.32 days^-1 (subreach 2-3). On October 7, the values were 2.04 days^-1 and 2.23 days^-1 respectively.