Evaluation of a groundwater corrective action at the Chem-Dyne Hazardous Waste Site using a telescopic mesh refinement modeling approach

Authors

  • David S. Ward,

  • David R. Buss,

  • James W. Mercer,

  • Shereen S. Hughes


Abstract

The available data base and hydrogeologic information for the Chem-Dyne hazardous waste site, located in southwestern Ohio, are typical of many Superfund sites. Data are localized because investigations conducted at these sites are for the purpose of defining contaminant plumes. Little or no data are available to characterize the regional flow systems which impart a controlling influence on the rate and direction of contaminant migration. To simulate groundwater flow and contaminant transport in this setting, a telescopic mesh refinement (TMR) approach is appropriate. This approach provides the means of accurately incorporating regional controlling factors into smaller model domains and also increased grid resolution in areas of critical importance. At the Chem-Dyne site a finite-difference model was applied at three scales: regional, local, and site. This application of TMR integrates the regional and local flow system characteristics to analyze the effectiveness of a proposed remedial action at the site scale. The TMR modeling approach permits effective flow and transport model construction and calibration to provide quantitative analysis of system response to a groundwater extraction-injection well clean-up system. Calibration of the flow models demonstrates the regional importance of induced river infiltration to groundwater pumping centers and the control of surface water features on the direction of plume migration. The site-scale transport model reveals that a significant portion of the volatile organic contaminants are not captured by the preliminary proposed system.

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