1. U.S. Geological Survey, Water Mission Area , Boulder, CO 80303, United States
2. U.S. Geological Survey, Geology, Energy and Minerals Science Center , 12201 Sunrise Valley Drive, Mailstop 954 , Reston, VA 20192, United States
3. U.S. Geological Survey, MD-DE-DC Water Science Center , 5522 Research Park Drive , Baltimore, MD 21228, United States
4. U.S. Geological Survey, New Jersey Water Science Center , 3450 Princeton Pike , Suite 110, Lawrenceville, NJ 08648, United States
5. U.S. Geological Survey, Water Mission Area , Menlo Park, CA 94025, United States