A biotracer test for characterizing the in-situ biodegradation potential associated with subsurface systems

Evaluating the feasibility of using intrinsic or accelerated in-situ bioremediation for a specific site requires a determination of the in-situ biodegradation potential of the target contaminants in the contaminated zone, which is a very difficult task. The purpose of this paper is to introduce a field-scale, controlled-release approach based on the use of a biodegradation tracer test. This method entails conducting a tracer experiment with one or more compounds whose biodegradation characteristics are well known. The biotracer test can be used to: (1) evaluate the general biodegradation potential associated with the zone of interest, (2) evaluate the response of the system to perturbations such as oxygen addition, and (3) evaluate the biodegradation potential for a specific contaminant. The utility of the biotracer test for the first application is illustrated with a test conducted at a field site contaminated by jet fuel. The results of the experiments indicate that it is possible to characterize the degradation potential of a selected site using biotracers. This method may, therefore, be a useful addition to our arsenal of methods for evaluating the feasibility and performance of in situ bioremediation.