Three Dimensional Visualization of Fractured Bedrock Characterization Data

A large volume of site characterization data has been collected on a former industrial facility located in northern New Jersey, where nitrobenzene and aniline groundwater contamination has migrated over 1,500 feet offsite and to a depth in excess of 450 feet in fractured bedrock.  These data provide valuable information, but the complexity of the site’s hydrogeology and contaminant distribution make it difficult to evaluate these data and to develop a coherent conceptual site model (CSM). A three-dimensional data visualization tool, Tecplot_™, maximized the value of data that were expensive to collect, and greatly improved site understanding.

Tecplot_™ is a data visualization tool that can simultaneously display multiple data types in three dimensions. The display can be rotated and zoomed in or out, and different types of data can be turned on and off to allow the clearest view of the data of most interest. The initial visualization of historical data for the northern New Jersey site supported a revised CSM and provided a basis for identifying site characterization data gaps. By showing the relationships between the occurrence and orientation of bedding plane and other fractures, particularly the intersections between fracture sets, and the distribution of contaminant concentrations, it made obvious the likely pathways of contaminant migration to target for further characterization. As additional data are collected, they will be added to the visualization to support further updates to the CSM.

Three-dimensional data visualization provides a powerful tool to help hydrogeologists integrate different types of site characterization data and interpret complex subsurface conditions. It also provides an effective tool for communicating complex conditions to regulators and other interested parties, with interactive presentations of data overlain on digital orthophotography, topography, and other information that put the data in context.