GEORGE F. PINDER, PhD, is Director of the Research Center for Groundwater Remediation Design and Professor of Civil and Environmental Engineering, Mathematics, and Computer Science at the University of Vermont. He has published many important articles and books, including Groundwater Modeling Using Geographical Information Systems (Wiley). Dr. Pinder's research focuses on the development and application of applied mathematics, especially numerical mathematics, to solve groundwater contamination and supply problems using computers.

MICHAEL A. CELIA, PhD, is Professor and Chair in the Department of Civil and Environmental Engineering at Princeton University. Dr. Celia conducts research in the areas of groundwater hydrology, numerical modeling, contaminant transport simulation, and multiphase flow physics.