Vertical circulation flows have become a well established in situ remediation technique. Their controllable flow field permits physical and biological remediation of the saturated as well as unsaturated subsoil. Large scale field experiments are carried out to systematically investigate the system efficacy and operation of groundwater circulation well in the remediation process. This paper is concerned with the realization of a 3-D numerical model of the field test site of the Institute for Hydromechanics in Karlsruhe - Knielingen. For the simulation of the 3-D flow field and transport, the numerical finite element model FRAC3DVS is used. The model has been calibrated With 3-D potential and transport measurements of multilevel monitoring wells. The problems related to mesh generation and error of discretization are discussed. The application is one of only few test sites with real 3-D field data for transportation simulation in a 3-D flow field.