1. Professor, Dept. of Civil and Environmental Engineering, Univ. of Maryland, College Park, MD 20742-3021.
2. Assistant Professor and Extension Specialist, Dept. of Biological and Agricultural Engineering, North Carolina State Univ., Raleigh, NC 27695-7625 (corresponding author).
3. Professor, Dept. of Civil and Environmental Engineering, Villanova Univ., Villanova, PA 19085.
4. Principal Engineer, Ecosite, Inc., 6470 Dobbin Rd., Suite F, Columbia, MD 21045.