Simulation of electrical potential differences near a contaminant plume excited by a point source of current

Abstract

Finite-difference simulations of electrical excitation of conductive contaminant plumes indicated that the approximate dimensions of a plume and the approximate location of its center of mass can be derived, under specified circumstances, from the resulting electrical potential fields. Direct electrical excitation of a contaminant plume by a point current source was simulated for homogenous and isotropic conditions as well as in the presence of conductive clay layers and lenses. When a very shallow water table was assumed, changes in the electrical potential field between baseline (preplume) conditions and conditions that included a developing plume graphically formed a difference dipole. Simulations suggested that electrical flow is channeled preferentially through the negative difference pole at the approximate location of the center of mass in a dispersive contaminant plume. Electrical flow was channeled directly through the negative difference pole at the terminal end of a conductive clay lens. Simulations showed that even in the presence of conductive clays, the approximate location of the center of mass of an evolving contaminant plume could be delineated. This illustrates the potential future value of this approach, assuming continued technological advances in the field. *** DIRECT SUPPORT *** A03BX002 00003