Abstract : The application of bioaugmentation technology has the potential to reduce both the time and cost associated with remediating groundwater contaminated with chlorinated volatile organic compounds (CVOCs), and it has become widely used as an in situ treatment alternative. The primary goals of this field demonstration were to evaluate the amount of Dehalococcoides sp. (DHC)-containing bacterial culture needed to effectively remediate a CVOC-contaminated plume, and to determine the effect of inoculum dose on remedial time. In addition, because of the low natural pH at the demonstration site, the ability to increase and maintain an elevated pH sufficient for successful bioremediation by adding buffers was evaluated. A chlorinated ethene groundwater plume present in the MAG-1 Area at Fort Dix, New Jersey was selected for the field demonstration component of this project. Bioaugmentation using Shaw s SDC-9 DHC-containing culture was performed in three separate groundwater recirculation loops, with one loop bioaugmented with 1 L of culture, the second loop bioaugmented with 10 L of culture, and the third loop bioaugmented with 100 L of culture. A fourth control loop was not bioaugmented. Groundwater monitoring was performed to evaluate Dehalococcoides (DHC) growth and migration, dechlorination kinetics, and aquifer geochemistry. The results of the demonstration were used to develop, evaluate and refine a one-dimensional bioaugmentation fate and transport screening model. The model developed during this project provided a reasonable prediction of the data generated during the field demonstration. The ability to predict results suggests that modeling potentially can serve as an effective tool for determining bioaugmentation dosage and predicting overall remedial timeframes, thus providing the Department of Defense (DoD) with more efficient and less expensive approaches for treating CVOC contaminated groundwater.