Use of a comprehensive calibration ``gauntlet`` approach for improved contaminants transport modeling at the F and H Area Seepage Basins

Many types of facility and monitoring data have been collected to support operation, closure and envirorunental restoration of the F and H-Area Seepage Basins at the Savannah River Site. Based on the various types of data, we developed contaminant transpose models to allow projection of contaminant releases and comparison of restoration alternatives. The modeling was performed in the following three stages: postulation of a conceptual model of the flow and transport system; development of a simplified analytical model based on a transfer function; development of a numerical model. A key feature of the work was use of both traditional data sources and calibration targets such as heads, geological data and pump test results, and non-traditional data sources and calibration targets, such as plume arrival times and shapes, contaminant release rates, and surface water concentrations. Throughout the process, the intermediate and final results were compared to all of the various data types and the earlier modeling stages. The result was a calibration ``gauntlet`` with explicit criteria for refinement and acceptance of the final model. Failure to match at any step within the gauntlet necessitated appropriate reformulation or modification of the model and rechecking for acceptable matches.