Previous studies have shown that nitrification of chloraminated drinking water can have deleterious effects on water quality. These studies also showed that the cause of nitrification is the oxidation of ammonia (used to form chloramines) to nitrite by autochthonous nitrifying bacteria. In this study, bench-scale experiments were conducted with fully treated drinking water to determine the optimum chloramine application conditions necessary to prevent nitrification in the distribution system. These experiments examined the survival and regrowth of nitrifying bacteria after exposure to three chloramine dosages, three weight ratios of chlorine to ammonia-nitrogen, three temperatures, and two contact times. The results indicate that the control of ammonia-oxidizing bacteria is highly dependent on temperature. Includes 22 references, table, figures.