1. Volunteer, U.S. Peace Corps, Cochabamba, Bolivia. E-mail: marcgoodhue@hotmail.com
2. Prof., Dept. of Civ. and Envir. Engrg., Univ. of Wisconsin, Madison, WI 53706. E-mail: edil@engr.wisc.edu
3. Prof., Dept. of Civ. and Envir. Engrg., Univ. of Wisconsin, Madison, WI 53706. E-mail: benson@engr.wisc.edu