Protection Agency through the Biosystem Field R Initiative, as well as by the Departments of Defense and Energy, indicate an increased emphasis on field-scale deployment and evaluation of bioremediation, with a supportive role for laboratory-scale testing. Due to the complex nature of contaminated soil and the variety of soil bioremediation techniques, the application and evaluation of bioremediation as a field-scale technology has not been consistent from site to site. An approach that takes into account site -specific characteristics that can be utilized for all sites and for all forms of bioremediation would provide the regulatory and user communities with a consistent and useful tool.
We wish to address the chemical mass balance as an important conceptual and practical component of field scale application, evaluation, and interpretation (monitoring) of soil bioremediation. A mass balance conceptual framework refers to the characterization of the physical phases and compartments in soil, and the determination of the influence of the compartments on the bioavailability and bioremediation of associated target chemicals. Soil phases and compartments include: (1) the soil-solid phase, which includes organic mat-