1. Dep. of Environmental Sciences; Univ. of California; Riverside CA 92521
2. USDA-ARS; Hydrology and Remote Sensing Lab.; 10300 Baltimore Ave., Bldg. 007, BARC-West Beltsville MD 20705
3. USDA-ARS; Environmental Microbial Safety Lab.; Powder Mill Road, Bldg. 173, BARC-East Beltsville MD 20705