Biscayne Aquifer is a body of permeable rock under South Florida that is South Florida’s primary source of drinking water. The Biscayne aquifer is an unconfined aquifer, which means that top portion of the aquifer is the water table. It is also a coastal aquifer because it merges with the floor of Biscayne Bay and the Atlantic Ocean. An aquifer is an underground layer of water-bearing permeable rock, or permeable mixtures of unconsolidated materials (gravel, sand, silt, or clay) (see also groundwater). ... Official language(s) English Capital Tallahassee Largest city Jacksonville Area - Total - Width - Length - % water - Latitude - Longitude Ranked 22nd 170 451 km² 260 km 800 km 17. ... An unconfined aquifer is a subterranean layer of water found below porous layers of earth. ...