Abt Global provided support – including spatial analysis and modeling of contaminant flow – as the litigation consultants on this multi-year, litigation project, which involved determining the source of a large plume of petroleum contamination.

Abt staff constructed a geographic information systems (GIS) project of all site data for use by the U.S. expert witnesses. The case required the investigation of the availability of spatial information and conversion/incorporation into the GIS.

The data sets we identified covered a wide variety of formats, scales, age, and quality, from numerous public agencies. Many data sets were not available in digital form, including historic aerial photos going back to the 1930s, historic topographic information, city sewer and oil refinery infrastructure, and hard copy maps of historic sample locations.

We incorporated the historical data into current data sets of similar features for comparison. Because the project was for litigation, the accuracy and documentation of processes was critical, and we carefully followed quality assurance procedures. Expert witnesses used data from the GIS project to support opinions in the case. The U.S. government reached a multimillion dollar settlement with the potential responsible party for the case.