In this study, Galerkin's finite element method is used to analyze the transport of a pollutant in a three-dimensional aquifer system. The collection of water quality data is expensive, and to gather information on the migration of contaminant plumes under field conditions is a lengthy process. Therefore, a numerical model is an excellent complementary tool which can predict the future migration of a plume in saturated aquifers. The method requires that the continuous variables be replaced with discrete variable elements. Each discrete subregion is modeled with the same transport equation. The concentrations are assembled at all nodes and solved on the IBM 3081K computer. The developed model has been validated against the existing analytical and numerical solutions in one, two, and three dimensions.