In 1993, a tracer solution containing benzene, p-xylene, napthalene, o-dichlorobenzene, and tritium was pulse injected into the subsurface at the Macrodispersion Experiment (MADE) site at Columbus Air Force Base in Mississippi. The hydraulic head, hydraulic conductivity, and contaminant concentration data from this experiment are documented in Boggs et al., 1993a. The Bioplume II biodegradation model was used to simulate this data. All organic tracers were considered as a lumped contaminant requiring 2.731 grams of oxygen to degrade 1.000 gram of total organic contaminants. Natural attenuation was modeled as both first-order decay and instantaneous degradation with first-order decay. The simulations matched the observed tritium data, but did not closely match the organic tracer data.