Using the Solver routine built into Excel, FATE 5 is able to calibrate the attenuation rate used by the Domenico model to match site-specific data. By calibrating the decay rate to site-specific measurements, FATE 5 can yield accurate predictions of long-term natural attenuation processes within a groundwater plume. In addition, FATE 5 includes a formulation of the transient Domenico solution used to help the user determine if the steady-state assumptions employed by the model are appropriate. The calibrated groundwater flow model can then be used either to i) predict upper-bound constituent concentrations in groundwater, based on an observed source zone concentration, or ii) back-calculate a lower-bound SSTL value, based on a user-specified exposure point concentration at the groundwater point of exposure (POE).
This paper reviews the major elements of the FATE 5 model and gives results for real-world applications. Key modeling assumptions and summary guidelines regarding calculation procedures and input parameter selection are also addressed.
FATE 5 was developed by Groundwater Services, Inc. (GSI) with support from the Partners in RBCA Implementation (PIRI) group. FATE 5 is based on the original Fate spreadsheet developed by Paul Johnson of Arizona State University formerly with Shell Development Company. The FATE 5 calculation engine was originally developed by John Gustafson also formerly at Shell Development Company, Houston, Texas.