1. Project Engineer, Hazen & Sawyer, 4011 Westchase Blvd., Raleigh, NC 27607.
2. Professor, Extension Specialist and University Faculty Scholar, Biological and Agricultural Engineering, North Carolina State Univ., Raleigh, NC 27695-7625 (corresponding author).
3. Extension Associate, Biological and Agricultural Engineering, North Carolina State Univ., NCSU Box 7625, Raleigh, NC 27695.
4. Engineer, S&EC, 8412 Falls of Neuse Rd., Suite 104, Raleigh, NC 27615.