1. Professor, Environmental Science and Engineering Division, and Director, Hydrologic Science and Engineering Program, Colorado School of Mines, Golden CO 80401. E-mail: jmccray@mines.edu
2. Extension Specialist, Onsite Sewage Treatment Program, Univ. of Minnesota, 1985 Buford Ave., St. Paul, MN 55108. E-mail: shc@umn.edu