1. Potentiometric surface of the Floridan aquifer in central Sumter County, Florida, September 1981 [cartographic material] Yale Public content 1982. 2002-06-01T04:00:00Z. 2023-04-14T03:01:26Z. Geological Survey (U.S.). The Survey. English. cartographic image. Public. Florida, Sumter County, and Sumter County (Fla.).