Chloride Concentration in Water from the Floridan Aquifer System
in the Brunswick, 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).
Brunswick Area
Since pumping began in the Brunswick area in
the late 1800's, ground-water withdrawal has lowered
the water level in the Upper Floridan aquifer (Krause
and Randolph, 1989). This water-level decline has
allowed saltwater to migrate upward into the
brackish-water zone of the Lower Floridan aquifer
and into the Upper Floridan aquifer in Brunswick
from the Fernandina permeable zone, which is at the
base of the Lower Floridan aquifer (Krause and
Randolph, 1989, p. D51). Chloride concentration in
water from the upper water-bearing zone of the Upper
Floridan aquifer is greater than 2,000 mg/L in parts of
Brunswick.
In the Brunswick, Glynn County area, eight
wells were pumped and sampled during 1997 for
chloride analysis. Graphs of chloride concentration in
water from eight wells tapping various zones
of the Floridan aquifer system are shown below.
Glynn County observation wells for which chloride-concentration graphs are
included in this document.
| Aquifer |
Well
number |
Site name |
Interval tapped |
| Lower Floridan |
34H399 |
USGS, test well 19 |
1,075-1,218 ft |
| Lower Floridan |
34H391 |
USGS, test well 16 |
1,070-1,159 ft |
Upper Floridan,
lower water-bearing zone |
34H403 |
USGS, test well 24 |
788-982 ft |
Upper Floridan,
upper water-bearing zone |
34H469 |
USGS, test well 2 |
540-566 ft |
Upper Floridan,
upper water-bearing zone |
33H133 |
USGS, test well 6 |
520-790 ft |
Upper Floridan,
upper water-bearing zone |
34H427 |
E.M. Champion, well 2 |
500-640 ft |
Upper Floridan,
upper water-bearing zone |
34H393 |
USGS, test well 17 |
615-723 ft |
Upper Floridan,
lower water-bearing zone |
33H127 |
USGS, test well 3 |
823-925 ft |
Chloride concentration in water from the
Floridan aquifer system in the Brunswick 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
The URL for this page is
<http://ga.water.usgs.gov/gw.conditions/gw1997/brunscl.html>.
If you have any questions or comments about this document contact: <webmaster-ga@usgs.gov>
Last modified: Wednesday, 28-Jul-2004 16:34:53 EDT