1. Environmental Engineer, CH2M-HILL, 2525 Airpark Dr., Redding, CA 96001.
2. Professor, Dept. of Civil and Environmental Engineering, 419 Durham Hall, Virginia Tech, Blacksburg, VA 24061 (corresponding author).
3. Associate Professor, Dept. of Civil and Environmental Engineering, 220A Patton Hall, Virginia Tech, Blacksburg, VA 24061.
4. Environmental Engineer, Stearns and Wheeler, 4201 Northview Dr., Bowie, MD 20716.
5. Environmental Engineer, Black and Veatch, 8604 Cliff Cameron Dr., Charlotte, NC 28269.