IN-SITU ESTIMATION OF TRANSPORT PARAMETERS - A FIELD DEMONSTRATION

Linear sorption coefficients and first-order biotransformation rates for para-dichlorobenzene (pDCB) and naphthalene are fit to data from a three-well forced-gradient (injection-production) field test performed at the site of an abandoned creosoting facility in Conroe, Texas. The breakthrough curve of an injected inert tracer, chloride, is used to describe the hydraulics of the field test. Along each streamline, the movement of a reactive solute is described by a one-dimensional transport equation. The hydraulic and streamline transport models are coupled through a combination integral, the evaluation of which yields the effluent concentration (at the production well) of that reactive solute as a function of time. Transport parameters for the field site, sorption coefficients and biotransformation rates for pDCB and naphthalene, are obtained through inverse analysis of effluent data obtained at one of the production wells. The method is formulated such that no formal treatment of dispersion is required.