Protective Pumping to Reduce Aquifer Pollution, Glynn County, Georgia^a

Abstract

Water‐level declines in the principal artesian aquifer have created a head imbalance between the aquifer and an underlying brackish‐water zone containing up to 4,550 mg/1 chloride. The brackish‐water zone leaks brackish water into the aquifer through several breaks in a confining unit. A relief well tapping the brackish‐water zone was drilled near a suspected break and pumped at about 3,000 gpm to lower the potential in the zone and bring it into hydrostatic equilibrium with the aquifer. The pumping apparently succeeded in decreasing the rate of brackish‐water leakage into the aquifer. Successive samples of water from a well tapping the aquifer and downgradient from the relief well showed a decrease in the chloride content. Several more relief wells may be necessary to ultimately control chloride contamination of the aquifer.

Saline-water intrusion in the Floridan Aquifer in the Fernandina Beach area, Nassau County, Florida

“…Protective pumping A method of particular appeal because of its apparently successful use in an area similar to that of the present investigation--Glynn County, Geor gia--is outlined by Gregg (1971). He described the use of a relief well which taps a saline-water zone underlying the principal artesian aquifer.…”