1. Process Engrg. Specialist, Cochrane Engineering Ltd., 600-5 Donald St., Winnipeg, MB, Canada R3L 2T4. E-mail: eliem@cochrane-group.ca
2. Prof., Dept. of Civ. and Envir. Engrg., Univ. of Alberta, Edmonton, AB, Canada T6G 2G7.
3. Assoc. Prof., Dept. of Civ. and Envir. Engrg., Univ. of Alberta, Edmonton, AB, Canada T6G 2G7.