Groome Endowed Professor
Department of Civil Engineering
Auburn University

Title: Worthiness of complex groundwater models for decision making— How to balance complexity with simplicity?

Abstract: Complex mathematical models are routinely used by groundwater hydrologists to predict contaminant concentration levels in polluted aquifers. These predictions are then used in risk-assessment and epidemiological studies, which are often completed either for resolving a court case or for developing a public-policy solution. Typical groundwater modeling studies utilize a variety of mathematical models with complexity levels ranging from simple analytical solutions to detailed three-dimensional numerical solutions that simulate multi-phase, multi-species, reactive transport systems. The goal of this discussion is to explore the value of using complex numerical models to resolve large, field-scale, practical problems that have limited data. I will review a chlorinated solvent contamination problem that occurred at a military site in Camp Lejeune, North Carolina, and will use it as an example to explore the limits of complex numerical modeling exercises. The lessons learned from the study will be used to reflect upon the following two questions related to model complexity: How should we decide how much is enough? Who should decide when enough is enough? This presentation will be based on a project I reviewed while I served as a member of National Academy of Sciences and Engineering study. The goal of this congressionally mandated study was to review available scientific evidences on the association between adverse health effect s and exposure to a contaminated water supply system at the U.S. Marine Corps Base Camp Lejeune (CLJ) in North Carolina.