Aquifer Delineation

The Groundwater Program delineates and maps the principal aquifers and confining units of the Coastal Plain.


Groundwater is a major source of water for public supply, irrigation, industry, and power generation. The Coastal Plain covers two-thirds of the State yet contains about 95% of its groundwater resources. It consists of layers of unconsolidated sand, clay, and limestone. Sand and limestone layers are porous and constitute the water-bearing zones called aquifers; clay layers are relatively impervious and constitute the confining units.

In an ongoing study, DNR is determining the location, depth, and thickness of the major aquifers and confining units utilizing data collected from water wells and core holes. Cores, which are cylindrical samples of the earth, provide information on the physical properties and boundaries of the aquifers and confining units. Core samples are also examined for microfossils, which are useful in correlating the aquifers and confining units across the State. Geophysical logs from water wells are used to identify and map the aquifers and confining units in those areas where cores unavailable.

This information is used to construct hydrogeologic cross sections and maps depicting the spatial distribution of the principal aquifers and confining units of the Coastal Plain.

Core Samples from a core hole near the Town of McBeeCore samples from a core hole near the Town of McBee.

Selected Reports

SCDNR Water Resources Report 5: Hydrogeologic framework of west-central South Carolina (1995) Aadland, R.K., Gellici, J.A., and Thayer, P.A.

SCDNR Water Resources Report 42: Hydrostratigraphy of the ORG-393 core hole at Orangeburg, South Carolina (2007) Gellici, J.A.

SCDNR Water Resources Report 43: Hydrostratigraphy of the AIK-2448 and AIK-2449 core holes in the Breezy Hill area of Aiken County, South Carolina (2007) Gellici, J.A.

USGS Professional Paper 1773: Groundwater availability in the Atlantic Coastal Plain of North and South Carolina (2010) Campbell, B.G. and Coes, A.L., editors.

Contact Information

For additional information, contact Joe Gellici (