Deuterated tracers for assessing natural attenuation in contaminated groundwater

Abstract

Three groundwater tracer tests using deuterium-labelled benzene, toluene, xylene and naphthalene (BTXN), trichloroethene (TCE) and munitions compounds (e.g. trinitrotoluene-TNT) were carried out in Australia to determine sorption, biodegradation and other transport parameters for contaminant plumes. The BTXN and TCE tests were natural gradient tests in an anaerobic sand aquifer, and the third munitions tracer test was a forced gradient test in a fractured basalt aquifer. Sorption coefficients, biodegradation rates and dispersion coefficients were estimated from multi-depth and location monitoring and modelling. The use of deuterium-labelled tracers is shown to be viable and attractive, although difficulties with in-field operations and environmental policy may limit application of such a technique.