1. Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, Damon S Williams Associates, Phoenix, Arizona 85016, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, Water Quality & Treatment Solutions, Inc., Castro Valley, California 94546, and U.S. Environmental Protection Agency, Technical Support Center, Cincinnati, Ohio 45268