1. Brown and Caldwell, St. Paul, MN 55101.
2. Department of Civil Engineering, University of Minnesota, Minneapolis, MN 55455.
3. Environmental Engineering Department, Texas A&M University–Kingsville, Kingsville, TX 78363.
4. Corresponding author: 122 Civil Engineering Building, University of Minnesota, 500 Pillsbury Drive, S.E., Minneapolis, MN 55455. Phone: 612-626-9846; Fax: 612-626-7750; E-mail: novak010@tc.umn.edu.