1. Hydrologist, Office of Surface Water, U.S. Geological Survey, 9818 Bluegrass Pkwy., Louisville, KY 40299. E-mail: dmueller@usgs.gov
2. Hydrologist, North Carolina Water Science Center, U.S. Geological Survey, 3916 Sunset Ridge Rd., Raleigh, NC 27607. E-mail: cwagner@usgs.gov