1. Former Graduate Research Assistant, Dept. of Civil Engineering and Engineering Mechanics, Univ. of Arizona, 1209 E. 2nd St., Tucson, AZ 85721.
2. Director, Environmental Affairs Dept., ASARCO LLC, 5285 E. Williams Circle, Tucson, AZ 85711.
3. Associate Professor, Dept. of Civil Engineering and Engineering Mechanics, Univ. of Arizona, 1209 E. 2nd St., Tucson, AZ 85721 (corresponding author).