1. Post Doctoral Research Scientist, Dept. of Civil and Environmental Engineering, Michigan Technological Univ., 1400 Townsend Dr., Houghton, MI 49931.
2. Professor, Dept. of Civil and Environmental Engineering, Michigan Technological Univ., 1400 Townsend Dr., Houghton, MI 49931 (corresponding author).
3. Presidential Professor, Dept. of Civil and Environmental Engineering, Michigan Technological Univ., 1400 Townsend Dr., Houghton, MI 49931.
4. Engineer, Western Lake Superior Sanitary District, 2626 Courtland St., Duluth, MN 55806.