Author(s)

C. M. Denton

Abstract

Modeling of emissions and contamination can result in significant cost-savings as compared with additional sampling and analysis, and is frequently utilized by potentially responsible parties as well as governmental agencies for air permitting, remedial investigations, corrective measures studies, and engineering design. The science of modeling has been challenged in federal and state courtrooms across the country. Questions have been raised as to the reliability, predictability and specificity of contaminant fate and transport modeling by various adversaries. This paper will review and discuss recent court rulings and evidentiary issues regarding contaminant fate and transport modeling in litigation and related expert witness testimony. Keywords: groundwater models, Daubert, expert witness, rules of evidence, CERCLA, limitations of modeling, fate and transport, MODFLOW, case studies. 1 Introduction This paper is a review of expert witness testimony utilizing computer modeling of the fate and transport of environmental contamination. Models provide an approximation of field situations, and are commonly used to simulate the movement of groundwater, surface water, air, and sediments, as well as the distribution of chemicals in these media. Models can be used to explain current conditions, predict future conditions, and recreate past conditions. There are two conditions that distinguish modeling for the courtroom from modeling used for typical consulting or research. First, because of the financial stakes typically associated with court cases, modeling for the courtroom often attracts more intense scrutiny than models created for other purposes. Second,

Keywords

groundwater models, Daubert, expert witness, rules of evidence,CERCLA, limitations of modeling, fate and transport, MODFLOW, case studies.