1. Department of Civil, Construction, and Environmental Engineering, Box 7908, North Carolina State University, Raleigh, North Carolina 27695-7908, and Joyce Engineering, Inc., Suite 203 Henderson Building, 2301 W. Meadowview Road, Greensboro, North Carolina 27407, and Bioreactor & BioSites Technology, Waste Management Inc., 2956 Montana Avenue, Cincinnati, Ohio 45211