Vertical circulation Bows have become a well established in situ remediation technique. Their controllable Bow field permits physical and biological remediation of the saturated, as well as the unsaturated subsoil. Earlier numerical calculations of the 3-D flow fields induced by Groundwater Circulation Wells Systems (German: Grundwasser-Zirkulations-Brunnen, abbr.: GZB) have been given by Herrling and Stamm, 1992. This paper discusses the results of the first experiments at a contaminated research site where the 3-D flow system could be fully tested.