1. Member, ASCE
2. Assoc. Prof., Dept. of Civ. and Envir. Engrg., Dir., Drinking Water Research Ctr., Florida International Univ., University Park, Miami, FL 33199. E-mail: tansel@eng.fiu.edu
3. Asst. Prof., Facu. of Sci. Maejo Univ., Chiang-Mai, Thailand, 50290.
4. Asst. Prof., Dept. of Chemical and Envir. Engrg., Illinois Inst. of Technol., 10 West 33rd St., Chicago, IL (corresponding author).