Characteristics of the Coastal Plains aquifer of South Carolina are being studied as a part of the Regional Aquifer Systems Analysis program of the U.S. Geological Survey. A framework has been developed to best represent the hydrology of the State by dividing the aquifers into a system of five aquifers. This framework includes a surficial aquifer consisting of coastal terrace deposits, a limestone and stratigraphically equivalent sand aquifer of Eocene age, and three sand aquifers of Cretaceous age. (USGS)