1. Staff Engineer, TetraTech, 350 Indiana St., No. 500, Golden, CO 80401.
2. Assistant Professor, Dept. of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (corresponding author).
3. Graduate Research Assistant, Dept. of Geology and Geological Engineering, Colorado School of Mines, 1516 Illinois St., Golden, CO 80401.