Louisiana ground-water map no. 22: generalized potentiometric surface of the Amite Aquifer and the "2,800-Foot" sand of the Baton Rouge area in southeastern Louisiana, June-August 2006 [electronic resource] / by Robert B. Fendick, Jr. ; U.S. Department of the Interior, U.S. Geological Survey ; prepared in cooperation with Louisiana Department of Transportation and Development Office of Public Works, Hurricane Flood Protection , and Intermodal Transportation Water Resources Programs