The Floridan aquifer system, composed of the Upper and Lower Floridan aquifers, is a thick sequence of Paleogene carbonate rock which spans an area of about in the southeastern United States, it underlies parts of which  state in the southern region of the United States, with part of its southern border formed by the Gulf of Mexico, and its western border is formed by the Mississippi River?
Floridan aquifer The Floridan aquifer system, composed of the Upper and Lower Floridan aquifers, is a thick sequence of Paleogene carbonate rock which spans an area of about in the southeastern United States. It underlies the entire state of Florida and parts of Alabama, Georgia, Mississippi, and South Carolina.
Surficial aquifer Surficial aquifers are shallow aquifers typically less than 50 ft thick, but larger surficial aquifers of about 60 ft have been mapped. They mostly consist of unconsolidated sand enclosed by layers of limestone, sandstone or clay and the water is commonly extracted for urban use. The aquifers are replenished by streams and from precipitation and can vary in volume considerably as the water table fluctuates. Being shallow,they are liable to contamination by fuel spills, industrial discharge, landfills, and saltwater. Parts of southeastern United States are dependent on surficial aquifers for their water supplies.