The Cockfield aquifer in Mississippi

The Cockfield Formation in the upper part of the Claiborne Group of Eocene age is a principal source of water supplies in Mississippi. The Cockfield Formation consists of beds of fine to medium sand, sandy carbonaceous clay, and thin beds of lignite. The largest withdrawal from the aquifer is in the Greenville-Leland area in Washington County where about 7.3 mgd was pumped in 1975. Long-term water-level trends indicate an average decline of about 1.5 ft per year. Specific capacity of wells in the Cockfield ranges from about 1.6 to 4.3 (gal/min)/ft. The dissolved-solids concentration in the water increases downdip to the west and the south. The Cockfield aquifer will continue to be major source of water supply in Mississippi and well fields producing 1 to 3 mgd can be developed in many places. (Woodard-USGS)