Single-well tracer tests in conjunction with multi-level observation wells were performed by Auburn University during the summer of 1984. The purpose of the tests was to determine the vertical variation of horizontal hydraulic conductivity in a confined aquifer. The results, which involved a tracer travel distance of 5.5 m, indicated that the hydraulic conductivity varied by about a factor of four throughout the aquifer thickness. During the late summer of 1984, a two-well tracer test was performed which involved travel distances of 38 m to 99 m. A bromide tracer slug was injected at one well while groundwater was simultaneously pumped from the other well. The two-well test, which required 32 days to complete, was then simulated by GeoTrans, Inc. using a 3-dimensional (3-D) advection-disperson model with a longitudinal dispersivity of 0.15 m, a transverse dispersivity of 0.05 m, and the permeability distribution measured independently in the single-well tests.