1. Gradute Student, Dept. of Civil and Environmental Engineering, Univ. of Cincinnati, Cincinnati, OH 45221-0071 (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of Cincinnati, Cincinnati, OH 45221-0071.
3. Director, Land Remediation and Pollution Control Division, National Risk Management Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH 45268.