The microbial filter concept can be generalized, even though the current focus is on intercepting chlorinated ethene plumes. It is possible to inoculate and eliminate contaminant source regions. and to bioremediate many classes of contaminants, especially when suites of microbial species are considered. Filter residence time is the time required for the contaminant to remain in the filter so that it can be degraded to the required concentration. It is a function of the subsurface contaminant flux, the intrinsic degradation rate, the attached population density, and the filter thickness. Intrinsic TCE degradation rate coefficients have been determined in laboratory tests.
Operational control is exercised over the attached population density and the filter thickness.
A model for cell transport and at tachment has been developed and tested in the laboratory and is used to predict attached population density. Filter thickness is controlled by the well pattern used to inject microbes. Detection limit is 0.5 ppb. Filter degradation capacity is the amount of TCE that can be degraded by the biofilter. Biodegradation of TCE causes a loss of key intracellular compounds required to oxidize the contaminant.