| Affiliation: | Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona 85721 (Li's current address is Arizona Dept. of Environmental Quality, 3033 N. Central Ave., Phoenix, Arizona 85012).;Department of Microbiology and Immunology, University of Arizona, Tucson, Arizona 85721 (Yahya's current address is San Jose Water Quality Lab, 1965 Workman Mill Rd., Whittier, California 90601).;Water Resources Division, U.S. Geological Survey, 3215 Marine Street, Boulder, Colorado 80225. |
