USGS Open-File Report 00-515
Chloride concentration in water from the Floridan aquifer system has been monitored in coastal Georgia since the 1950's. During 1999, water samples were collected from 85 wells that tap the Floridan aquifer system in the Savannah and Brunswick areas and analyzed for chloride concentration. Graphs of chloride concentration in water for 14 of these wells are shown in the following pages. 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).
Table 5. Observation wells for which chloride-concentration graphs are
included in this report
[GGS, Georgia Geologic Survey; USGS, U.S. Geological Survey]
| County | Aquifer | USGS Site Identification Number |
Well Identification number |
Site name | Open interval (in feet) |
|---|---|---|---|---|---|
| Chatham | Lower Floridan | 320151080540403 | 38Q196 | USGS, test well 1, point 2 | 870-925 |
| Chatham | Lower Floridan | 320122080510202 | 39Q017 | USGS, test well 7, point 1 | 710-745 |
| Chatham | Lower Floridan | 320122080510203 | 39Q018 | USGS, test well 7, point 2 | 630-670 |
| Chatham | Lower Floridan | 320151080540502 | 38Q004 | USGS, test well 4 | 606-657 |
| Chatham | Upper Floridan | 320622081063701 | 37Q185 | GGS, Hutchinson Island, test well 1 | 274-360 |
| Chatham | Upper Floridan | 315906081011202 | 37P114 | Skidaway Institute, test well 2 | 262-400 |
| Glynn | Lower Floridan | 310750081292001 | 34H399 | USGS, test well 19 | 1,075-1,218 |
| Glynn | Lower Floridan | 310818081294201 | 34H391 | USGS, test well 16 | 1,070-1,159 |
| Glynn | Upper Floridan, lower water-bearing zone | 310822081294201 | 34H403 | USGS, test well 24 | 788-982 |
| Glynn | Upper Floridan, upper water-bearing zone | 311020081295205 | 34H469 | USGS, test well 2 | 540-566 |
| Glynn | Upper Floridan, upper water-bearing zone | 311007081301702 | 33H133 | USGS, test well 6 | 520-790 |
| Glynn | Upper Floridan, upper water-bearing zone | 311016081294202 | 34H427 | E.M. Champion, well 2 | 500-640 |
| Glynn | Upper Floridan, upper water-bearing zone | 310825081294201 | 34H393 | USGS, test well 17 | 615-723 |
| Glynn | Upper Floridan, lower water-bearing zone | 311007081301701 | 33H127 | USGS, test well 3 | 823-925 |
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Last updated Monday, 26-Jun-2000 15:14:17 EDT
The URL for this page is http://ga.water.usgs.gov/publications/ofr00-151/chlorides.html