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Oc t 10 1996 16phl 1 EU TECHNIC OUS I ES 110 39;4 ? 39/51 Third Foruni on Innovative hazardous Wn%tc Treatment Technologies Domestic and Intern,itional, Junc 11-13, 1991, Dalla%fTexas, U.S A (sponsored by U S EPA) ' IN SITU GROUNDWATER REMEDIATION OF STRIPPABLE CONTAMINANTS BY VACUUM VAPORIZER WELLS (UVB). OPERATION OF THE WELL AND REPORT ABOUT CLEANED INDUSTRIAL SITES B Herrling', J. Stamm', E.J. Alesi P Brinnel"', F Hirschberger' M.R Sick' liistitute of 1 Iydromechanu.s, University of Karlsruhe, Kaiserstrasse 12, D-7500 ' Karlsrulie, Germany GfS mbH, Dettinger Str. 146, D-7312 Kirchheim/Teck, Germany Ilydrodata GmbH, Gattenhofer Weg 29, D-6370 Oberursel, Germany ' INTRODUCTION ' The contamination of groundwater by strippable substances is a significant problem in all industrial countries. For remediating aquifers in situ technologies are favored to rediae the investment and operating costs. The paper presents an in situ ' method that can remove strippable substances, e.g volatile chlorinated hydrocarbons, and BTEX, from the subsurface (groundwater zone, capillary fringe, and unsaturated zone), it is currently being used at numerous locations in Germany. This technology is an alternative to conventional hydraulic remediation measures (pumping, off-site cleaning, and reinfiltration of groundwater) The contaminated groundwater is stnpped in situ by air in a below atmospheric pressure field within a so-called "vacuum vaporizer well" ' (German. Unterdruck-Verdampfer-Brun nen, UVB) The used air, charged with volatile contaminants, is cleaned using activated carbon. 1 The UVB technique produces a vertical circulation flow in the area surrounding the well, which catches the total aquifer,T-be vertical velocity component yields a desired flow through the horizontal structure of a native aquifer. Numerical results demonstrate the size of the sphere of influence and the capture zone of a well or well field, extended ' field measurements have been and continue to be taken (Herrling et al. 1991a). The advantages of the UVB technique concerning the vertical circulation system around the wells instigated thought about other applications, even without stripping the groundwater. The realization of in situ bio0egradation is such an example and seems to be an appropriate alternative to other existing hydraulic systems. The different nutrients ' and/or electron acceptors needed for ,biological activity can be added when the groundwater passes the well casing (Herrling et al. 1991b). This Paper presents the UVB technique for in situ removal of strippable ' contaminants. The circulation system, sphere of influence, and capture zone of a UVB or UVB field as essential components of the hydraulic flow system are discussed in detail. Further diagrams for dimensioning a UVB or UVB field are presented. Two extended examples demonstrate the groundwater and soil remediation at different sites located in the Rhine-Ruhr area and in Berlin using different installations of the UVB system. The short remediation period and the low cost niveau for the UVB investment and the well operation are only two among other advantages of the UVB