The kinetics of nitrate inhibition of carbon tetrachloride (CT) transformation were examined using a denitrifying consortium. Comparison of data from fed-batch experiments to the model reported by Hooker et al. indicate that the inhibition constant ranges between 3.2 and 21 mg/L, with an average of 8.8 mg/L. This range is much lower than the previously reported value of 169 mg/L. Simulations using the corrected parameter accurately reflect this new data and the data reported by Hooker et al. In contrast, the earlier reported coefficient value does not reflect the data reported in this work. (c) 1995 John Wiley & Sons, Inc.