PlumeSeeker{sup TM}: A Model-Based Least-Cost Monitoring Network Design Technology for 3-D Contaminant Plume Boundary Delineation - 19582
Delineating the extent of contamination in an aquifer is a pre-requisite for designing remediation schemes as well as for satisfying regulators and stakeholders. Contaminant plumes are typically delineated using either monitoring well locations with observed concentrations below remedial goals or with computer-drawn contour maps based on available concentration measurements in the groundwater. Computer-generated plume information lacks ground truth resulting in uncertainty about the true limits of contamination. The location of groundwater delineation wells is usually chosen solely based on professional judgement and experience. Both approaches can be inefficient, risky and often unnecessarily expensive. PlumeSeeker{sup TM} is a software-based technology well-suited for the optimal delineation of radiological or emerging contaminant plumes with single or multiple source locations. The software is an enhancement of a university research code for plume delineation using geostatistical and stochastic modeling tools integrated with the widely used groundwater flow and transport modeling software MODFLOW-SURFACT{sup TM}. PlumeSeeker{sup TM} increases the overall confidence in the location and geometry of the plume boundary through the sequential (i.e. a rank-ordered listing) or batch (i.e. a suite of multiple wells) selection of existing or new monitoring wells based on the criteria of maximizing plume boundary uncertainty reduction and on new field information. Using PlumeSeeker{sup TM}, remediation managers can optimally locate new wells at sites where well installation costs are high or hydrogeology is complex. Applicable at sites with or without existing monitoring wells, PlumeSeeker{sup TM} is particularly powerful for optimally allocating project resources (labor, well installation, and laboratory costs) between existing wells and sampling at new locations. An application of PlumeSeeker{sup TM} at a DoD installation demonstrates how the cost of delineating a plume can be minimized. (authors)