1. Environmental Research Center, Department of Civil, Architectural and Environmental Engineering, University of Missouri–Rolla, Rolla, MO 65409
2. Carollo Engineers, Fountain Valley, CA 92708
3. Environmental Research Center, Department of Civil, Architectural and Environmental Engineering, University of Missouri–Rolla, Rolla, MO 65409. Phone: 573-341-4041; Fax: 573-341-4729; E-mail: adams@umr.edu (C. Adams)