Chloride concentration in the Floridan aquifer, Savannah, GA

Chloride Concentration in Water from the Floridan Aquifer System in the Savannah, Georgia Area

Chloride concentration in water from the Floridan aquifer system has been monitored in coastal Georgia since the 1950's. During 1997, water samples were collected from 23 wells that tap the Floridan aquifer system in the Savannah and Brunswick areas and analyzed for chloride concentration. Although chloride concentration may fluctuate in the intervals between sample-collection periods, measured points on these plots are connected by straight lines to assist visualization. Chloride concentration in water from the Upper Floridan aquifer in most of the coastal Georgia area is less than 40 milligrams per liter (mg/L) (Clarke and others, 1990, p. 48), which is within the 250 mg/L drinking- water standard established by the Georgia Department of Natural Resources (1977) and the U.S. Environmental Protection Agency (1990). Chloride concentration in water from the Upper Floridan aquifer that exceeds the drinking-water standard has been detected in the Brunswick area. Water in the Lower Floridan aquifer generally has high chloride concentration in the Savannah and Brunswick areas. Chloride concentration in water from the Fernandina permeable zone at the base of the Lower Floridan aquifer has been measured as high as 30,000 mg/L (Krause and Randolph, 1989, p. D51).

Savannah Area

During 1997, twelve wells were pumped and sampled in Chatham County, six of which are summarized below. Data from these wells indicate that chloride concentration generally increases with depth below land surface and is not changing appreciably with time.

Chatham County observation wells for which chloride-concentration graphs are included in this document.

Aquifer	Well number	Site name	Interval tapped
Lower Floridan	38Q196	USGS, test well 1 point 2	870-925 ft
Lower Floridan	9Q017	USGS, test well 7 point 1	710-745 ft
Lower Floridan	39Q018	USGS, test well 7 point 2	630-670 ft
Lower Floridan	38Q004	USGS, test well 4	606-657 ft
Upper Floridan	37Q185	GGS, Hutchinson Island, test well 1	274-360 ft
Upper Floridan	37P114	Skidaway Institute, test well 2	262-400 ft

Chloride concentration in water from the Upper and Lower Floridan aquifers in the Savannah area.
Text and graphs are from Ground-Water Conditions in Georgia, 1997 by Alan M. Cressler, U.S. Geological Survey Open-File Report 98-172, 104 pages.

Go to the 1997 Georgia Ground-Water Monitoring page, or to the Georgia Water Resources page
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Last modified: Wednesday, 28-Jul-2004 16:34:54 EDT