U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2011–5048

Groundwater Conditions and Studies

in Georgia, 2008–2009
Cover. (Left) Well 13FF14 located in Lawrenceville, Georgia, being pumped during a 72-hour 

aquifer test. Water levels and discharge were continuously monitored during the test. The well is 

280 feet deep with 23 feet of casing and is completed in the crystalline rock aquifer. Photo by 

Michael D. Hamrick, USGS.

(Center) A hydrologic technician from the Groundwater Information and Project Support Unit 

prepares to lower a geophysical logging tool in a well. The well is located at the Albany Water Gas 

and Light Commission well field, Dougherty County, Georgia. Photo by Debbie Warner Gordon, USGS. 

(Right) Test well being drilled at Fort Stewart, Liberty County, Georgia, to assess the water-bearing 

properties of the surficial aquifer as a potential source of irrigation water for athletic fields. Photo 

shows the well being developed with a drill rig air-lifting water from the well prior to conducting a 

24-hour pumping test. The well was completed to 100 feet with screen set from 50 to 90 feet. Results 

from the 24-hour pumping test indicated that the well yield ranged from 545 to 550 gallons per minute. 

Photo by Michael D. Hamrick, USGS.

Preface

This report is published biennially in stop format and presents a summary of groundwater 

conditions in Georgia, and a description of ongoing groundwater studies. This report is 

the culmination of a concerted effort by personnel of the U.S. Geological Survey, Georgia 

Water Science Center who collected, compiled, organized, analyzed, verified and edited and 

assembled the report. In addition to the authors, who had primary responsibility for ensuring 

that the information contained herein is accurate and complete, the following individuals 

contributed substantially to the collection, processing, tabulation, and review of the data:

Gregory S. Cherry

John S. Clarke

Alan M. Cressler

Julia L. Fanning

Debbie Warner Gordon

Anthony J. Gotvald

Jamal A. Grimes

Michael D. Hamrick

O. Gary Holloway

John K. Joiner

Andrew E. Knaak

Stephen J. Lawrence

John J. McCranie

Jonathan W. Musser

Welby L. Stayton

Lynn J. Torak

Lester J. Williams
Groundwater Conditions and Studies 

in Georgia, 2008–2009

By Michael F. Peck, David C. Leeth, and Jaime A. Painter

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2011– 5048
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2011

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS

For an overview of USGS information products, including maps, imagery, and publications, 

visit http://www.usgs.gov/pubprod

To order this and other USGS information products, visit http://store.usgs.gov

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the 

U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Peck, M.F., Leeth, D.C., and Painter, J.A., 2011, Groundwater conditions and studies in Georgia, 2008–2009; 

U.S. Geological Survey Scientific Investigations Report 2011–5048, 83 p.
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................2

Purpose and Scope ..............................................................................................................................2

Methods of Analysis, Sources of Data, and Data Accuracy.........................................................3

Georgia Well-Identification System...................................................................................................5

Cooperating Organizations and Agencies........................................................................................5

Groundwater Resources ....................................................................................................................6

Permitted Water-Use Data for Georgia during 2009 and Groundwater-Use Trends 

for 2005–2009..........................................................................................................................10

Groundwater Conditions.............................................................................................................................12

Groundwater Levels ...........................................................................................................................12

Surficial Aquifer System...........................................................................................................14

Brunswick Aquifer System.......................................................................................................16

Upper Floridan Aquifer..............................................................................................................18

Southwestern Area ..........................................................................................................20

City of Albany–Dougherty County Area ........................................................................22

South-Central Area...........................................................................................................24

East-Central Area .............................................................................................................26

Northern Coastal Area.....................................................................................................28

Central Coastal Area ........................................................................................................30

City of Brunswick Area ....................................................................................................32

Southern Coastal Area ....................................................................................................34

Lower Floridan Aquifer and Underlying Units in Coastal Georgia.....................................36

Claiborne and Gordon Aquifers...............................................................................................38

Clayton Aquifer...........................................................................................................................40

Cretaceous Aquifer System .....................................................................................................42

Paleozoic-Rock Aquifers ..........................................................................................................44

Crystalline-Rock Aquifers.........................................................................................................46

Groundwater Quality in the Upper and Lower Floridan Aquifers ...............................................49

City of Albany Area....................................................................................................................50

City of Savannah Area ..............................................................................................................52

City of Brunswick Area .............................................................................................................54

Real-Time Specific Conductance Monitoring in Brunswick Area.....................................56

Camden County Area ................................................................................................................58

Selected Groundwater Studies in Georgia, 2008–2009 .........................................................................61

City of Albany Cooperative Water Program ...................................................................................62

Groundwater Monitoring Program for the Augusta–Richmond County Area ..........................64

City of Brunswick and Glynn County Cooperative Water Program............................................66

Fort Stewart–Hunter Army Airfield Alternative Water Resources ............................................68

Monitoring of Groundwater and Surface-Water Resources

in the City of Lawrenceville Area........................................................................................70

Georgia Agricultural Water-Use Project.........................................................................................72

Groundwater Information and Project Support.............................................................................74
iv

Conversion Factors and Datums

Multiply By To obtain

Length

inch 2.54 centimeter (cm)

inch 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

yard (yd) 0.9144 meter (m)

Flow rate

gallon per minute (gal/min) 0.06309 liter per second (L/s)

gallon per day (gal/d) 0.003785 cubic meter per day (m3

/d)

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3

/s)

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88). Historical data collected and stored as National Geodetic Vertical Datum of 1929 

have been converted to NAVD 88 for use in this publication.

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Historical data collected and stored as North American Datum of 1927 (NAD 27) have been 

converted to NAD 83 for use is in this publication. 

Altitude, as used in this report, refers to distance above the vertical datum.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius 

(μS/cm at 25 °C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) 

or micrograms per liter (μ/L)

Selected Groundwater Publications, Conferences, and Outreach, 2008–2009.................................76

Georgia Water Resources Conference for 2009............................................................................76

Other Conferences and Outreach Events.......................................................................................76

Selected U.S. Geological Survey Reports and Conference Proceedings Articles .................76

U.S. Geological Survey Reports ..............................................................................................76

2009 Georgia Water Resources Conference Proceedings Papers ...................................77

Appendix. Regression Statistics ..............................................................................................................79
Abstract

The U.S. Geological Survey collects groundwater data 

and conducts studies to monitor hydrologic conditions, better 

define groundwater resources, and address problems related to 

water supply, water use, and water quality. In Georgia, water 

levels were monitored continuously at 179 wells during 2008 

and 181 wells during 2009. Because of missing data or short 

periods of record (less than 3 years) for several of these wells, 

a total of 161 wells are discussed in this report. These wells 

include 17 in the surficial aquifer system, 19 in the Brunswick 

aquifer and equivalent sediments, 66 in the Upper Floridan 

aquifer, 16 in the Lower Floridan aquifer and underlying 

units, 10 in the Claiborne aquifer, 1 in the Gordon aquifer, 

11 in the Clayton aquifer, 12 in the Cretaceous aquifer system, 

2 in Paleozoic-rock aquifers, and 7 in crystalline-rock aquifers. 

Data from the well network indicate that water levels generally 

rose during the 2008–2009 period, with water levels rising 

in 135 wells and declining in 26. In contrast, water levels 

declined over the period of record at 100 wells, increased at 

56 wells, and remained relatively constant at 5 wells.

In addition to continuous water-level data, periodic 

water-level measurements were collected and used to 

construct potentiometric-surface maps for the Upper Floridan 

aquifer in Camden, Charlton, and Ware Counties, Georgia, 

and adjacent counties in Florida during September 2008 

and May 2009; in the Brunswick, Georgia area during 

July 2008 and July–August 2009; and in the City of Albany–

Dougherty County, Georgia area during November 2008 

and November 2009. In general, water levels in these areas 

were higher during 2009 than during 2008; however, the 

configuration of the potentiometric surfaces in each of the 

areas showed little change.

Groundwater quality in the Floridan aquifer system is 

monitored in the Albany, Savannah, Brunswick, and Camden 

County areas of Georgia. In the Albany area, nitrate as 

nitrogen concentrations in the Upper Floridan aquifer during 

2008–2009 generally increased, with concentrations in 

two wells above the U.S. Environmental Protection Agency 

(USEPA) 10-milligrams-per-liter (mg/L) drinking-water 

standard. In the Savannah area, measurement of specific 

conductance and chloride concentration in water samples from 

discrete depths in three wells completed in the Upper Floridan 

aquifer indicate that chloride concentrations in the Upper 

Floridan aquifer showed little change and remained below 

the 250 mg/L USEPA secondary drinking-water standard. 

Chloride concentrations in the Lower Floridan aquifer 

increased slightly at Tybee Island and Skidaway Island, 

remaining above the drinking-water standard. In the 

Brunswick area, maps showing the chloride concentration of 

water in the Upper Floridan aquifer were constructed using 

data collected from 28 wells during July 2008 and from 

29 wells during July–August 2009, indicate that chloride 

concentrations remained above the USEPA secondary 

drinking-water standard in an approximately 2-square-mile 

area. During 2008–2009, chloride concentrations decreased, 

with a maximum decrease of 160 mg/L, in a well located 

in the northern part of the Brunswick area.

In the Camden County area, chloride concentration 

during 2008–2009 was analyzed in water samples collected 

from eight wells, six of which were completed in the Upper 

Floridan aquifer and two in the Lower Floridan aquifer. 

In most of the wells sampled during this period, chloride 

concentrations did not appreciably change; however, since 

the closure of the Durango Paper Company in October 2002, 

chloride concentrations in the Upper Floridan aquifer near the 

paper mill decreased from a high of 184 mg/L in May 2002 

to 41 mg/L in September 2009.

Groundwater studies conducted in Georgia during 

2008–2009 include the following:

• evaluation of groundwater flow, water-quality, and waterlevel monitoring in the Augusta–Richmond County area;

• evaluation of groundwater flow, water-quality, and waterlevel monitoring in the City of Albany–Dougherty 

County area; 

• evaluation of saltwater intrusion, water-level, and waterquality monitoring in the City of Brunswick–Glynn 

County area; 

• collection of groundwater data in and adjacent to the State 

of Georgia; 

• assessment of the sustainability of groundwater resources

 in the City of Lawrenceville area;

• evaluation of alternative groundwater resources, flow, water 

quality, and water-level monitoring Hunter Army Airfield 

and Fort Stewart, Georgia; and

• evaluation and quality assurance of agricultural pumpage 

in Georgia.

Groundwater Conditions and Studies 

in Georgia, 2008–2009

by Michael F. Peck, David C. Leeth, and Jaime A. Painter
2 Groundwater Conditions and Studies in Georgia, 2008–2009

Introduction

Reliable and impartial scientific information on the 

occurrence, quantity, quality, distribution, and movement of 

water is essential to resource managers, planners, and others 

throughout the Nation. The U.S. Geological Survey (USGS), 

in cooperation with numerous local, State, and Federal 

agencies, collects hydrologic data and conducts studies to 

monitor hydrologic conditions and better define the water 

resources of Georgia and other States and territories.

Groundwater-level and quality data are essential for 

water-resources assessment and management. Water-level 

measurements from observation wells are the principal source 

of information about the hydrologic stresses on aquifers and 

how these stresses affect groundwater recharge, storage, 

and discharge. Long-term, systematic measurement of water 

levels provides essential data needed to evaluate changes 

in the resource over time, develop groundwater models and 

forecast trends, and design, implement, and monitor the 

effectiveness of groundwater management and protection 

programs (Taylor and Alley, 2001). Groundwater-quality data 

are necessary for the protection of groundwater resources 

because deterioration of groundwater quality may be 

virtually irreversible, and treatment of contaminated groundwater can be expensive (Alley, 1993). Reliable water-use 

data are important to many organizations and individuals 

in support of research and policy decisions and are essential 

in understanding the effects of humans on the hydrologic 

system (Hutson and others, 2004).

Purpose and Scope

This report presents an overview of groundwater 

conditions, permitted water use, and hydrologic studies 

conducted during 2008–2009 by the USGS in Georgia. 

Summaries are presented for selected groundwater studies 

along with objectives and progress. These summaries 

include the following;

• evaluation of groundwater flow, water-quality, and waterlevel monitoring in the Augusta–Richmond County area; 

• evaluation of groundwater flow, water-quality, and 

water-level monitoring in the City of Albany–Dougherty 

County area; 

• evaluation of saltwater intrusion, water-level, and waterquality monitoring in the City of Brunswick–Glynn 

County area; 

• collection of groundwater data in and adjacent to the 

State of Georgia; 

• assessment of the sustainability of groundwater 

resources in the City of Lawrenceville area; 

• evaluation of alternative groundwater resources, at 

Hunter Army Airfield and Fort Stewart, Georgia; 

• evaluation and quality assurance of agricultural

pumpage in Georgia; and

• publication of reports on groundwater conditions

in Georgia (listed on page 4). 

Permitted water-use data compiled for 2005–2009 

and reported herein are based on State-mandated reporting 

requirements for water users withdrawing more than 

100,000 gallons per day (gal/d). State-mandated reporting 

includes data for public supply, industrial and commercial, 

and thermoelectric-power water use; however, reporting of 

information on irrigation water use is not mandated and, 

therefore, not discussed in this report.

Continuous water-level measurements were obtained 

from 179 wells during 2008 and 181 wells during 2009; 

however, data from 161 wells are summarized herein. Of the 

181 wells equipped with continuous water-level recorders 

during 2009, 151 wells had electronic data recorders that 

recorded water levels at 60-minute intervals, and the data 

generally were retrieved bimonthly. Thirty wells had real-time 

satellite telemetry that recorded water levels at 60-minute 

intervals. Three of the real-time sites were equipped to 

monitor water levels and specific conductance, and at another 

site only specific conductance was monitored. Real-time 

satellite telemetry data are transmitted every 1 to 4 hours 

(based on equipment) for display on the USGS Georgia Water 

Science Center Web site at http://waterdata.usgs.gov/ga/nwis/

current?type=gw/.

Groundwater levels in major aquifers are presented as 

hydrographs for selected wells throughout Georgia. Estimated 

annual water-level change is reported for the period of record 

and for 2008–2009. Additional well information can be 

obtained from the USGS National Water Information System 

(NWIS) at http://waterdata.usgs.gov/ga/nwis/gw/.

In addition to continuous water-level recording, periodic 

water-level measurements were collected to complete 

potentiometric surface maps for the Upper Floridan aquifer. 

In southwestern Georgia near Albany, measurements were 

collected in 81 wells during November 2008 and in 64 wells 

during November 2009. In the southern coastal area of 

Georgia, including Camden, Charlton, and Ware Counties and 

adjacent counties in Florida, water-level measurements were 

collected during September 2008 and May 2009 (Kinnaman 

and Dixon, 2009a, b).

The quality of groundwater in the Floridan aquifer system 

is being monitored in the Albany–Dougherty County area 

and in several areas along the Georgia coast. In the Albany 

area, nitrate as nitrogen concentrations in the Upper Floridan 

aquifer were determined in water from 25 wells during 

November 2008 and from 13 wells during November 2009. In 

the coastal area, groundwater quality of the Upper and Lower 

Floridan aquifers was determined in the Savannah, Brunswick, 

and St. Marys areas. In the Savannah area, groundwater 

quality was assessed in four wells by using a combination of 

borehole fluid-resistivity logs and grab samples collected at 

discrete depths. 
26R001

31U008

26R001

31U008

Tattnall

Evans

Emanuel

Jenkins

Screven

Effingham

Bulloch

Candler

Burke

Toombs

EXPLANATION

0 10 20 MILES

0 10 20 KILOMETERS

Base from U.S. Geological Survey 

1:100,000-scale digital data

Upper Floridan aquifer

Northern coastal area 

N

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water-level 

rise > 0.01 foot per year

Downward trend—Water-level 

decline > 0.01 foot per year

GEORGIA

Upper Floridan aquifer

Central Coastal area

Well 36Q008 (Chatham County, Georgia)

Monthly mean water level below land surface, in feet

Blank

where

data are

missing

Trend

19552009

1954

1960196519701975198019851990199520002005

 60

 70

 80

 90

 100

 110

 120

 130

Introduction 3

Long-term chloride concentrations in the Brunswick area 

are presented by using composite-sample data from five wells 

for the periods 1960–2009 and 1965–2009 together with maps 

showing chloride concentrations in the Brunswick area during 

July 2008 (26 wells) and July–August 2009 (26 wells). Data 

are presented from a network of three continuous, specificconductance monitoring sites (used as surrogate data for chloride 

concentration) surrounding the chloride plume at Brunswick. In 

the St. Marys area of Camden County, chloride-concentration 

data from 8 wells are presented for the period 1984–2009.

Methods of Analysis, Sources of Data, 

and Data Accuracy

To illustrate long-term (period of record) and more recent 

(2008–2009) water-level changes, hydrographs showing 

monthly mean water levels are presented together with maps 

showing water-level trends during 2008–2009. To estimate 

water-level trends, the Levenberg–Marquardt (LMA) method 

for minimization of a weighted least-squares merit function 

(Janert, 2010) was used to determine a straight-line fit to both

recent and period-of-record monthly-mean groundwater levels 

(see example graph below). Estimated water levels from these 

straight-line fits were used to compute an annual rate of change

(yearly slope) for the period of record and for 2008–2009. 

A more thorough discussion of the LMA method is presented 

at the end of this report along with associated summary 

statistics for each well and for straight-line fits (appendix). 

Water-level trends are presented on tables, hydrographs, 

and maps for each aquifer and sub-area in the groundwater 

level section of this report. Trends for 2008–2009 are 

presented on maps either by an upward arrow for a positive 

rate of change of 0.01 foot per year (ft/yr) or greater, or a 

downward arrow for a negative rate of change of 0.01 ft/yr 

or greater. A circle represents no water-level change on the 

map when the change was less than ± 0.01 ft/yr. Additional 

well information can be obtained from the USGS NWIS at 

http://waterdata.usgs.gov/ga/nwis/gw/.

Water samples were analyzed for nitrate as nitrogen at 

the USGS laboratory in Denver, Colorado. Chloride analyses 

were conducted at the St. Johns River Water Management 

District in Palatka, Florida (for Camden County), and at 

TestAmerica Laboratory, Savannah, Georgia. Additional waterquality data for Georgia can be obtained from the USGS NWIS 

at http://waterdata.usgs.gov/ga/nwis/qw/.

Permitted water-use data for 2008–2009 were compiled 

from the Georgia Water-Use Data System (GWUDS). The 

GWUDS contains permitted water-use information on public 

supplies, industrial and commercial supplies, and thermoelectricpower and hydroelectric-power uses for 1980–2009. These 

data are limited to permitted water withdrawals of 100,000 

gal/d or greater, in compliance with Georgia water law that 

requires withdrawal permits for all public-supply, industrial, 

and other water users who withdraw more than 100,000 gal/d 

(http://rules.sos.state.ga.us/docs/391/3/2/03.pdf).

Water-level trends for 2008–

2009 are presented on maps 

either by an upward arrow for 

a positive rate of change of 

0.01 foot per year or greater, 

or a downward arrow for a 

negative rate of change of 

0.01 foot per year or greater. 

A circle represents no waterlevel change.

Example hydrograph 

showing monthly mean 

water levels in well 36Q008 

for the period 1954–2009, 

and period-of-record trend.
4 Groundwater Conditions and Studies in Georgia, 2008–2009

Year of data 

collection

USGS report 

series and number Author(s) Year of publication

1977 OFR 79 –213 U.S. Geological Survey 1978

1978 OFR 79 –1290 Clarke, J.S., Hester, W.G., and O’Byrne, M.P. 1979

1979 OFR 80 –501 Mathews, S.E., Hester, W.G., and O’Byrne, M.P. 1980

1980 OFR 81–1068 Mathews, S.E., Hester, W.G., and O’Byrne, M.P. 1981

1981 OFR 82 –904 Mathews, S.E., Hester, W.G., and McFadden, K.W. 1982

1982 OFR 83 –678 Stiles, H.R., and Mathews, S.E. 1983

1983 OFR 84 –605 Clarke, J.S., Peck, M.F., Longsworth, S.A., and McFadden, K.W. 1984

1984 OFR 85 –331 Clarke, J.S., Longsworth, S.A., McFadden, K.W., and Peck, M.F. 1985

1985 OFR 86 –304 Clarke, J.S., Joiner, C.N., Longsworth, S.A., McFadden, K.W., and Peck, M.F. 1986

1986 OFR 87–376 Clarke, J.S., Longsworth, S.A., Joiner, C.N., Peck, M.F., McFadden, K.W., 

and Milby, B.J.

1987

1987 OFR 88 –323 Joiner, C.N., Reynolds, M.S., Stayton, W.L., and Boucher, F.G. 1988

1988 OFR 89 –408 Joiner, C.N., Peck, M.F., Reynolds, M.S., and Stayton, W.L. 1989

1989 OFR 90 –706 Peck, M.F., Joiner, C.N., Clarke, J.S., and Cressler, A.M. 1990

1990 OFR 91–486 Milby, B.J., Joiner, C.N., Cressler, A.M., and West, C.T. 1991

1991 OFR 92–470 Peck, M.F., Joiner, C.N., and Cressler, A.M. 1992

1992 OFR 93 –358 Peck, M.F., and Cressler, A.M. 1993

1993 OFR 94 –118 Joiner, C.N., and Cressler, A.M. 1994

1994 OFR 95 –302 Cressler, A.M., Jones, L.E., and Joiner, C.N. 1995

1995 OFR 96 –200 Cressler, A.M. 1996

1996 OFR 97–192 Cressler, A.M. 1997

1997 OFR 98 –172 Cressler, A.M. 1998

1998 OFR 99 –204 Cressler, A.M. 1999

1999 OFR 00 –151 Cressler, A.M. 2000

2000 OFR 01–220 Cressler, A.M., Blackburn, D.K., and McSwain, K.B. 2001

2001 WRIR 03–4032 Leeth, D.C., Clarke, J.S., and Craigg, S.D., and Wipperfurth, C.J. 2003

2002 –2003 SIR 2005–5065 Leeth, D.C., Clarke, J.S., Wipperfurth, C.J., and Craigg, S.D. 2005

2004 –2005 SIR 2007–5017 Leeth, D.C., Peck, M.F., and Painter, J.A. 2007

2006–2007 SIR 2009–5070 Peck, M.F., Painter, J.A. and Leeth, D.C. 2009

Previously published U.S. Geological Survey reports on groundwater conditions in Georgia.

[OFR, Open-File Report; WRIR, Water-Resources Investigations Report; SIR, Scientific Investigations Report]
Georgia Well-Identification System

Wells described in this report are identified according to 

a system based on the index of USGS 7.5-minute topographic 

maps of Georgia. Each map in Georgia has been assigned a 

two- to three-digit number and letter designation (for example, 

07H) beginning at the southwestern corner of the State. 

Numbers increase sequentially eastward, and letters advance 

alphabetically northward. Quadrangles in the northern part of 

the State are designated by double letters: AA follows Z, and 

so forth. The letters I, O, II, and OO are not used in the wellidentification system. Wells inventoried in each quadrangle are 

numbered consecutively, beginning with 001. Thus, the fourth 

well inventoried in the 11A quadrangle is designated 11A004. 

In the USGS NWIS database, this information is stored in the 

“Station Name” field; in NWIS Web, it is labeled “Site Name.”

Cooperating Organizations and Agencies

Groundwater monitoring and hydrologic studies in 

Georgia are conducted in cooperation with numerous local 

organizations and State and Federal agencies. Cooperating 

organizations and agencies include;

• Department of Defense, U.S. Army

• Georgia Department of Agriculture

• Georgia Department of Natural Resources,

Environmental Protection Division

• St. Johns Water Management District (Florida)

• Jekyll Island Authority

• Flint River Water Planning and Policy Center

• Albany Water, Gas, and Light Commission

• Camden County

• Glynn County

• Lee County

• City of Brunswick/Glynn County

• City of Lawrenceville

• City of Augusta/Richmond County

With the exception of the Federal agencies, all of these 

organizations participate in the USGS Cooperative Water 

Program, an ongoing partnership between the USGS and 

State and local agencies. The program enables joint planning 

and funding for systematic studies of water quantity, quality, 

and use. Data obtained from these studies are used to guide 

water-resources management and planning activities and 

provide indications of emerging water problems. For a more 

complete description of the Cooperative Water Program, 

see Brooks (2001)

References Cited

 Alley, W.M., 1993, General design consideration, in

Alley, W.M., ed., Regional groundwater quality: 

New York, N.Y., Van Nostrand Reinhold, 634 p.

Brooks, M.H., 2001, Cooperative Water Program—A 

partnership in the Nation’s water-resources program: 

U.S. Geological Survey Fact Sheet 128–01, 2 p.

Hutson, S.S., Barber, N.L., Kenny, J.F., Linsey, K.S., 

Lumia, D.S., and Maupin, M.A., 2004, Estimated use 

of water in the United States in 2000: U.S. Geological 

Survey Circular 1268, 46 p.

Janert, P.K., 2010, Gnuplot in action—Understanding data with 

graphs: Greenwich, Conn., Manning Publications Co., 360 p.

Kinnaman, S.L., and Dixon, J.F., 2009a, Potentiometric 

surface of the Upper Floridan aquifer in the St. Johns 

River Water Management District and vicinity, Florida, 

September 2008: U.S. Geological Survey Scientific 

Investigations Map 3070, 1 sheet; available online at 

http://pubs.usgs.gov/sim/3070/.

Kinnaman, S.L., and Dixon, J.F., 2009b, Potentiometric 

surface of the Upper Floridan aquifer in the St. Johns River 

Water Management District and vicinity, Florida, May 2009: 

U.S. Geological Survey Scientific Investigations Map 3091, 

1 sheet; available online at http://pubs.usgs.gov/sim/3091/.

Taylor, C.J., and Alley, W.M., 2001, Groundwater-level 

monitoring and the importance of long-term water-level 

data: U.S. Geological Survey Circular 1217, 68 p.

Introduction 5
6 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Resources 

Contrasting geologic features and landforms of the 

physiographic provinces of Georgia (see map on p. 7 and 

table on p. 8–9) affect the quantity and quality of groundwater 

throughout the State. The surficial aquifer system is present 

in each of the physiographic provinces. In the Coastal Plain 

Physiographic Province, the surficial aquifer system consists 

of layered sand, clay, and limestone. The surficial aquifer 

system usually is under water-table (unconfined) conditions 

and provides water for domestic and livestock use. The 

surficial aquifer system is semiconfined to confined locally in 

the coastal area. In the Piedmont, Blue Ridge, and Valley and 

Ridge Physiographic Provinces, the surficial aquifer system 

consists of soil, saprolite, stream alluvium, colluvium, and 

other surficial deposits. 

The most productive aquifers in Georgia are in the 

Coastal Plain Physiographic Province in the southern half of 

the State. The Coastal Plain is underlain by alternating layers 

of sand, clay, dolomite, and limestone that dip and thicken to 

the southeast. Coastal Plain aquifers generally are confined, 

except near their northern limits where they crop out or are 

near land surface. Aquifers in the Coastal Plain include the 

surficial aquifer system, Brunswick aquifer system, Upper and 

Lower Floridan aquifers, Gordon aquifer system, Claiborne 

aquifer, Clayton aquifer, and Cretaceous aquifer system.

In the Valley and Ridge Physiographic Province, 

groundwater is transmitted through primary and secondary 

openings in folded and faulted sedimentary and metasedimentary rocks of Paleozoic age, herein referred to as 

“Paleozoic-rock aquifers.”

In the Piedmont and Blue Ridge Physiographic Provinces, 

the geology is complex and consists of structurally deformed 

metamorphic and igneous rocks. Groundwater is transmitted 

through secondary openings along fractures, foliation, joints, 

contacts, or other features in the crystalline bedrock. In 

these provinces, aquifers are referred to as “crystalline-rock 

aquifers.” For a more complete discussion of the State’s 

groundwater resources, see Clarke and Pierce (1985).

References

Clarke, J.S., 2003, The surficial and Brunswick aquifer 

systems—alternative groundwater resources for coastal 

Georgia, in Hatcher, K.J., ed., Proceedings of the 2003 

Georgia Water Resources Conference, April 23–24, 2003: 

Athens, Georgia, University of Georgia, CD–ROM.

Clarke, J.S., Brooks, Rebekah, and Faye, R.E., 1985, 

Hydrology of the Dublin and Midville aquifer system of 

east-central Georgia: Georgia Geologic Survey Information 

Circular 74, 62 p.

Clarke, J.S., Faye, R.E., and Brooks, Rebekah, 1983, 

Hydrogeology of the Providence aquifer of southwest 

Georgia: Georgia Geologic Survey Hydrologic 

Atlas 11, 5 sheets.

Clarke, J.S., Hacke, C.M., and Peck, M.F., 1990, Geology 

and groundwater resources of the coastal area of Georgia: 

Georgia Geologic Survey Bulletin 113, 106 p. 

Clarke, J.S., and Pierce, R.R., 1985, Georgia groundwater 

resources, in U.S. Geological Survey, National Water 

Summary, 1984: U.S. Geological Survey Water-Supply 

Paper 2275, p. 179–184.

Cressler, C.W., 1964, Geology and groundwater resources 

of Walker County, Georgia: Georgia Geologic Survey 

Information Circular 29, 15 p.

Cressler, C.W., Thurmond, C.J., and Hester, W.G., 1983, 

Groundwater in the greater Atlanta region, Georgia: 

Georgia Geologic Survey Information Circular 63, 144 p.

Hicks, D.W., Krause, R.E., and Clarke, J.S., 1981, 

Geohydrology of the Albany area, Georgia: Georgia 

Geologic Survey Information Circular 57, 31 p.

Jones, L.E., and Maslia, M.L., 1994, Selected groundwater 

data, and results of aquifer tests for the Upper Floridan 

aquifer, Brunswick, Glynn County, Georgia, area: U.S. 

Geological Survey Open-File Report 94–520, 107 p.

Krause, R.E., and Randolph, R.B., 1989, Hydrogeology 

of the Floridan aquifer system in southeast Georgia 

and adjacent parts of Florida and South Carolina: U.S. 

Geological Survey Professional Paper 1403-D, 65 p.

Peck, M.F., Joiner, C.N., and Cressler, A.M., 1992, Groundwater conditions in Georgia, 1991: U.S. Geological Survey 

Open-File Report 92–470, 137 p. 
Dade

Walker

Catoosa Whitfield

Murray

Fannin

Gilmer

Union

Towns

Rabun

Stephens Habersham

White

Lumpkin

Dawson

Pickens Chattooga Gordon

Floyd Bartow Cherokee Forsyth

Hall Banks Franklin Hart

Elbert Madison

Jackson

Gwinnett Barrow

DeKalb Fulton

Cobb

Paulding

Polk

Haralson

Carroll

Douglas

Fayette

Clayton

Coweta

Heard

Henry

Rockdale

Newton

Walton

Morgan

Oconee

Clarke Oglethorpe

Wilkes Lincoln

Columbia

Richmond

Jefferson

Washington

Baldwin Monroe Jones

Pike Lamar Meriwether

Troup

Harris

Muscogee

Chattahochee

Marion

Schley

Macon

Dooly Pulaski Dodge

Wilcox

Crisp

Sumter Webster

Stewart

Quitman

Randolph

Terrell Lee

Worth

Turner Ben Hill

Coffee

Bacon

Glynn

Brantley

Pierce

Ware

Berrien Atkinson

Cook

Tift

Mitchell Colquitt

Baker

Calhoun Dougherty Clay

Early

Miller

Seminole

Decatur Grady Thomas Brooks Lowndes

Lanier

Echols

Clinch

Charlton

Camden

Irwin

Wheeler Toombs

Tattnall

Bryan

Long

Wayne

Jeff Davis

Telfair

Liberty

McIntosh

Montgomery

Chatham

Talbot

Upson

Crawford

Taylor

Bibb

Twiggs

Wilkinson

Johnson

Emanuel

Treutlen

Laurens Bleckley Houston

Peach

Jenkins Screven

Effingham

Candler Bulloch

Burke

Glascock

McDuffie

Warren

Jasper Putnam Hancock Butts Spalding

Taliaferro Greene

Appling

Evans

? ?

? ? ?

? ?

? ?

? ? ?

?

?

Brunswick

Columbus

Savannah

Albany

Augusta

Macon

Atlanta

Atlantic

Ocean

GEORGIA

Fall Line

Coastal Plain Province 

Brunswick aquifer system

Upper and Lower Floridan aquifers 

Gordon aquifer system

Claiborne and Clayton aquifers 

Cretaceous aquifer system

EXPLANATION

Valley and Ridge and Appalachian 

 Physiographic Provinces

 Paleozoic-rock aquifers

Piedmont and Blue Ridge Provinces 

 Crystalline-rock aquifers

Surficial aquifer system—Present 

 throughout State. Shown on block, 

 not on map 

0 20 40 60 MILES

0 20 40 60 KILOMETERS

Base modified from 

U.S. Geological Survey

1:5,000,000-scale 

digital data

BLUE RIDGE

VALLEY AND RIDGE

AND

APPALACHIAN 

PLATEAUS

PIEDMONT

COASTAL

PLAIN

Fall Line

31°

32°

33°

34°

85°

83°

84°

82°

81°

Introduction 7

Areas of use of major aquifers in Georgia (modified from Clarke and Pierce, 1985).
8 Groundwater Conditions and Studies in Georgia, 2008–2009

Well characteristics

Aquifer name Aquifer description Depth (ft) Yield (gal/min) 

Typical range Typical range May exceed

Surficial aquifer system Unconsolidated sediments 

and residuum; generally

unconfined. However, in 

the coastal area of the 

Coastal Plain, at least 

two semiconfined aquifers 

have been identified

11–300 2–25 75 

Brunswick aquifer system, 

including upper and 

lower Brunswick 

aquifers

Phosphatic and dolomitic 

quartz sand; generally 

confined

85– 390 10 –30 180 

Upper and Lower Floridan 

aquifers

Limestone, dolomite, and 

calcareous sand; 

generally confined

40 – 900 1,000 – 5,000 11,000 

Gordon aquifer system Sand and sandy limestone; 

generally confined

270–530 87–1,200 1,800 

Claiborne aquifer Sand and sandy limestone; 

generally confined

20–450 150–600 1,500 

Clayton aquifer Limestone and sand;

generally confined

40 – 800 250 – 600 2,150 

Cretaceous aquifer system Sand and gravel;

generally confined

30 –750 50 –1,200 3,300 

Paleozoic-rock aquifers Sandstone, limestone

and dolomite;

generally confined

15 –2,100 1– 50 3,500 

Crystalline-rock aquifers Granite, gneiss, schist,

and quartzite; confined 

and unconfined

40 – 600 1– 25 500 

Groundwater Resources

Aquifer and well characteristics in Georgia [modified from Clarke and Pierce, 1985; Peck and others, 1992; ft, foot; gal/min, gallon per minute]
Introduction 9

Hydrologic response Remarks

Water-level fluctuations are caused mainly by variations in precipitation, 

evapotranspiration, and natural drainage or discharge. In addition, water 

levels in the City of Brunswick area are influenced by nearby pumping, 

precipitation, and tidal fluctuations (Clarke and others, 1990). Water 

levels generally rise rapidly during wet periods and decline slowly during 

dry periods. Prolonged droughts may cause water levels to decline 

below pump intakes in shallow wells, particularly those located on 

hilltops and steep slopes, resulting in temporary well failures. Usually, 

well yields are restored by precipitation (Clarke, 2003).

Primary source of water for domestic and livestock supply 

in rural areas. Supplemental source of water for irrigation 

supply in coastal Georgia.

In the coastal area, the aquifers may respond to pumping from the Upper 

Floridan aquifer as a result of the hydraulic connection between the 

aquifers. Elsewhere, the water level mainly responds to seasonal variations

in recharge and discharge. In Bulloch County, unnamed aquifers equivalent to the upper and lower Brunswick aquifers are unconfined 

to semiconfined and are influenced by variations in recharge from 

precipitation and by pumping from the Upper Floridan aquifer; in the 

Wayne and Glynn County area, the aquifers are confined and respond 

to nearby pumping (Clarke and others, 1990; Clarke, 2003).

Not a major source of water in coastal Georgia, but 

considered a supplemental water supply to the 

Upper Floridan aquifer. 

In and near outcrop areas, the aquifers are semiconfined, and water levels

 in wells tapping the aquifers fluctuate seasonally in response to variations in recharge rate and pumping. Near the coast, where the aquifers 

are confined, water levels primarily respond to pumping, and fluctuations 

related to recharge are less pronounced (Clarke and others, 1990).

Supplies about 50 percent of groundwater in Georgia. The 

aquifer system is divided into the Upper and Lower Floridan 

aquifers. In the Brunswick area, the Upper Floridan aquifer 

includes two freshwater-bearing zones—the upper waterbearing zone and the lower water-bearing zone. In the 

Brunswick area and in southeastern Georgia, the Lower 

Floridan aquifer includes the brackish-water zone, the 

deep freshwater zone, and the Fernandina permeable zone 

(Krause and Randolph, 1989). The Lower Floridan aquifer 

extends to more than 2,700 ft in depth and yields highchloride water below 2,300 ft (Jones and Maslia, 1994).

Water levels are influenced by seasonal fluctuations in recharge from 

precipitation, discharge to streams, and evapotranspiration (Clarke 

and others, 1985).

Major source of water for irrigation, industrial, and publicsupply use in east-central Georgia.

Water levels are mainly affected by precipitation and by local and regional 

pumping (Hicks and others, 1981). The water level is generally highest 

following the winter and spring rainy seasons, and lowest in the fall 

following the summer irrigation season.

Major source of water for irrigation, industrial, and publicsupply use in southwestern Georgia.

Water levels are affected by seasonal variations in local and regional 

pumping (Hicks and others, 1981).

Major source of water for irrigation, industrial, and publicsupply use in southwestern Georgia.

Water levels are influenced by variations in precipitation and pumping 

(Clarke and others, 1983, 1985).

Major source of water in east-central Georgia. Supplies 

water for kaolin mining and processing; includes the 

Providence aquifer in southwestern Georgia, and the 

Dublin, Midville, and Dublin–Midville aquifer systems in 

east-central Georgia.

Water levels are affected mainly by precipitation and local pumping 

(Cressler, 1964).

Not laterally extensive. Limestone and dolomite aquifers 

are the most productive. Storage is in regolith, primary 

openings, and secondary fractures and solution openings

in rock. Springs in limestone and dolomite aquifers 

discharge at rates of as much as 5,000 gal/min. Sinkholes 

may form in areas of intensive pumping.

Water levels are affected mainly by precipitation and evapotranspiration, 

and locally by pumping (Cressler and others, 1983). Precipitation can 

cause a rapid rise in water levels in wells tapping aquifers overlain by 

thin regolith.

Storage is in regolith and fractures in rock.
Ground water

423 Mgal/d (million gallons per day)

Surface water

3,250 Mgal/d (million gallons per day)

Industrial and

commercial

11 percent Thermoelectric power 360 Mgal/d 1 percent

3 Mgal/d

Public supply Industrial and Public supply

49.5 percent commercial 27 percent

209 Mgal/d 50 percent 878 Mgal/d

211 Mgal/d Thermoelectric power

62 percent

2,012 Mgal/d

Percentages of permitted water use in Georgia by category and source, 2009.

10 Groundwater Conditions and Studies in Georgia, 2008–2009

Permitted Water-Use Data for Georgia during 

2009 and Groundwater-Use Trends for 2005–2009

Permitted water-use data can be used to assess potential 

effects of groundwater withdrawal on groundwater systems. 

Only water-use data from permitted public supply, industrial 

and commercial, and thermoelectric systems are included in 

this report. Estimates for irrigation, livestock, and domestic 

use are omitted. During 2009, permitted water withdrawal 

in Georgia totaled 3,672 million gallons per day (Mgal/d) of 

which about 88 percent (3,250 Mgal/d) was from surface-water 

sources and 12 percent (423 Mgal/d) was from groundwater 

sources. Permitted withdrawal by public-supply systems 

totaled about 1,087 Mgal/d, about 81 percent of which was 

from surface-water sources and 19 percent was from groundwater sources (see pie charts below). Eighteen thermoelectric 

plants, the largest water users in Georgia, withdrew about 

2,015 Mgal/d during 2009, mostly from surface-water sources. 

Permitted withdrawals by industrial and commercial users 

totaled about 571 Mgal/d, with 63 percent was from surfacewater sources and 37 percent from groundwater sources. 

The major industrial users in Georgia include paper, textiles, 

chemicals, stone and clay, and mining.

Compared to 2007, total withdrawals for 2009 decreased 

by 975 Mgal/d. Thermoelectric power withdrawals saw 

the largest decrease during 2007–2009 (793 Mgal/d), 

mostly from surface-water sources. The largest decrease 

for groundwater-supplied users was for industrial and 

commercial systems, which decreased from 242 Mgal/d in 

2007 to 211 Mgal/d in 2009. Public-supply withdrawals from 

groundwater sources also decreased during this period from 

221 Mgal/d in 2007 to 209 Mgal/d in 2009.

To understand the areal distribution and trends of 

permitted groundwater withdrawal in the State, data from 

2005 to 2009 were grouped into five areas as depicted in 

the map and graphs (facing page). Permitted groundwater 

withdrawal in each of the five areas decreased during 

2005–2009. This decrease largely is a result of continued 

conservation efforts made by industrial and municipal users. 

In the Coastal Plain, groundwater use decreased from 14.4 to 

6.97 Mgal/d, mostly because of a reduction in industrial 

withdrawals. In the northern one-half of the State, groundwater 

use also decreased 1.74 Mgal/d in the Valley and Ridge area 

and 3.85 Mgal/d in the Piedmont and Blue Ridge area. These 

decreases were largely due to conservation efforts by publicsupply and industrial systems during the most recent drought.
0

100

Western Coastal Plain

0

50

100

250

150

50

150

50

200

Central Coastal Plain

0

100

200

300

Eastern Coastal Plain

2005 2006 2007 2008 2009

Withdrawal, in million gallons per day

0

25

50

Valley and Ridge

2005 2006 2007 2008 2009

0

25

50

Piedmont and Blue Ridge

Withdrawal, in million gallons per day

GEORGIA

0 20 40 60 MILES

0 20 40 60 KILOMETERS

Base modified from 

U.S. Geological Survey

1:5,000,000-scale

digital data

Piedmont and

 Blue Ridge

Coastal Plain

Central

Eastern

Valley and Ridge

Water-use area

EXPLANATION

N

Western

Fall Line

Permitted Water-Use Data for Georgia during 2009 and Groundwater-Use Trends for 2005–2009 11

Groundwater withdrawals in Georgia by water-use area, 2005 –2009. 
Well 07N001 (Randolph County, Georgia)

Monthly mean water level 

below land surface, in feet

Monitoring began 1965

 130

 140

 150

 160

 170

 180

19571960

19651970

19751980

1985

1990

1995

2000

2005

2009

Trend Blank

where

data are

missing

12 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Conditions

Groundwater Levels

Maps and tables in this section provide an overview 

of groundwater levels in major aquifers in Georgia during 

2008–2009. Hydrographs of selected wells are presented to 

demonstrate period-of-record and 2008–2009 water-level 

trends. Discussion of each aquifer is subdivided into areas 

where wells likely would have similar water-level fluctuations 

and trends if they were unaffected by pumping. The map on 

the facing page shows the locations of selected wells that 

were continuously monitored by the U.S. Geological Survey 

during the 2009 calendar year, including 30 wells that were 

monitored in real time. 

Changes in aquifer storage cause changes in groundwater 

levels in wells. Taylor and Alley (2001) described many 

factors that affect groundwater storage; these factors are 

discussed briefly here. When recharge to an aquifer exceeds 

discharge, groundwater levels rise; when discharge from 

an aquifer exceeds recharge, groundwater levels decline. 

Recharge varies in response to precipitation and surface-water 

infiltration to an aquifer. Discharge occurs as natural flow from 

an aquifer to streams and springs, as evapotranspiration, and 

as withdrawal from wells. Hydraulic responses and controls 

on groundwater levels in major aquifers in Georgia are 

summarized on pages 8 and 9.

Water levels in aquifers in Georgia typically follow 

a cyclical pattern of seasonal fluctuation. Water levels rise 

during winter and spring because of increased recharge from 

precipitation and decline during summer and fall because of 

decreased recharge, greater evapotranspiration, and pumping. 

The magnitude of fluctuations can vary greatly from season 

to season and from year to year in response to changing 

climatic conditions. 

Groundwater pumping is the most important human 

activity that affects the amount of groundwater in storage 

and the rate of discharge from an aquifer (Taylor and Alley, 

2001). As groundwater storage is depleted within the radius 

of influence of pumping, water levels in the aquifer decline 

forming a cone of depression around the well. In areas having a 

high density of pumped wells, multiple cones of depression can 

form and combine to produce water-level declines across a large 

area. These declines may alter groundwater-flow directions,

reduce flow to streams, capture water from a stream or adjacent 

aquifer, or alter groundwater quality. The effects of sustained 

pumping can be seen in the hydrograph of well 07N001 

completed in the Clayton aquifer in Randolph County (below).

Reference 

Taylor, C.J., and Alley, W.M., 2001, Ground-water-level 

monitoring and the importance of long-term water-level 

data: U.S. Geological Survey Circular 1217, 68 p.

Example hydrograph showing monthly mean water levels and trend line for well 07N001 for the period 

1965–2009, Randolph County, Georgia.
Dade

Walker

Catoosa Whitfield

Murray

Fannin

Gilmer

Union

Towns

Rabun

Stephens Habersham

White

Lumpkin

Dawson

Pickens

Gordon Chattooga

Floyd Bartow Cherokee Forsyth

Hall Banks Franklin Hart

Jackson Madison Elbert

Barrow Gwinnett

DeKalb Fulton

Cobb

Paulding

Polk

Haralson

Carroll

Douglas

Fayette

Clayton

Coweta

Heard

Henry

Rockdale

Newton

Walton

Morgan

Oconee

Clarke Oglethorpe

Wilkes Lincoln

Columbia

Richmond

Jefferson

Washington

Baldwin

Monroe Jones

Pike Lamar Meriwether

Troup

Harris

Muscogee

Chattahoochee

Marion

Schley

Macon

Dooly Pulaski Dodge

Wilcox

Crisp

Sumter Webster

Stewart

Quitman

Randolph

Terrell Lee

Worth

Turner Ben Hill

Coffee Bacon

Glynn

Brantley

Pierce

Ware

Berrien Atkinson

Cook

Tift

Mitchell Colquitt

Baker

Dougherty Calhoun Clay

Early

Miller

Seminole

Decatur

Grady

Thomas Brooks Lowndes

Lanier

Echols

Clinch Charlton Camden

Irwin

Wheeler Toombs

Tattnall

Evans

Bryan

Long

Wayne

Jeff Davis Appling

Telfair

Liberty

McIntosh

Chatham

Montgomery

Talbot

Upson

Crawford

Taylor

Bibb

Twiggs

Wilkinson

Johnson

Emanuel

Treutlen

Laurens Houston Bleckley

Peach

Jenkins

Screven

Effingham

Bulloch Candler

Burke

Glascock

McDuffie

Warren

Hancock

Jasper Putnam

Butts Spalding

Greene

Atlantic

Ocean

EXPLANATION

Continuous

Real-time

Fall Line

0 20 40 60 MILES

0 20 40 60 KILOMETERS

Base modified from 

U.S. Geological Survey

1:5,000,000-scale digital data

Monitoring well—At this scale, 

 all wells may not be visible 

 because of close proximity

31°

32°

33°

34°

85°

83°

84°

82°

81°

GEORGIA

Groundwater Conditions 13

Locations of monitoring wells used to collect long-term water-level data in Georgia 

during 2008–2009.
Well 11AA01 (Spalding County, Georgia)

Well 07H003 (Miller County, Georgia)

Well 35P094 (Chatham County, Georgia)

Monthly mean water level below and above (–) land surface, in feet

Blank

where

data are

Monitoringbegan 1943

missingMonitoring began 1980

0

3

6

9

 12

1942

–5

0

5

 10

 15

 20

 25

5

 10

 15

 20

 25

Trend

Surficial Graphs

194519501955

1960

196519701975

1980

1985

1990

1995

20002005

2009

14 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Surficial Aquifer System

Water levels measured in 17 wells were used to define 

conditions in the surficial aquifer system during 2008–2009 

(map and table, facing page). Groundwater in the surficial 

aquifer system typically is in contact with the atmosphere 

(referred to as an unconfined or water-table aquifer), but 

locally (especially in coastal Georgia) may be under pressure 

exerted by overlying sediments or rocks (referred to as a 

confined aquifer). Where unconfined, water levels change 

quickly in response to recharge and discharge. Consequently, 

hydrographs from these wells show a strong relation to 

climatic fluctuations. Water-level hydrographs for selected 

wells (below) illustrate monthly mean water levels for the 

period of record. The hydrographs show mostly seasonal 

variations, with periodic upward or downward trends that 

respectively reflect surplus or deficits in rainfall. These 

periodic trends tend to be level over the long term.

Water levels in the surficial aquifer have shown little 

change in long-term trend during the period of record with 

rates of change less than ±0.01 foot per year (ft/yr) in three 

of the wells, declines of 0.01 to 0.33 ft/yr in nine wells, and 

rises of 0.02 to 0.41 ft/yr in five wells. During 2008–2009, 

water levels in all but two of the wells rose from 0.12 to 

2.85 ft/yr corresponding to an increase in precipitation at the 

end of a 2-year drought in 2008. Well 09FF18 in Cobb County 

had a decline of 0.38 ft/yr during 2008–2009, continuing a 

downward trend since 2001. The reason for this downward 

trend is unknown but may be related to nearby pumping.
GEORGIA

CUMBERLAND PLATEAU

VALLEY

AND

RIDGE

PIEDMONT AND

BLUE RIDGE

COASTAL PLAIN

Fall Line Richmond

Jefferson

Washington

Muscogee

Chattahochee

Marion

Schley Macon

Dooly Pulaski Dodge

Wilcox Crisp

Sumter Webster

Stewart

Quitman

Randolph

Terrell Lee

Worth

Turner Ben Hill

Coffee Bacon

Glynn

Brantley

Pierce

Ware

Berrien Atkinson

Cook

Tift

Colquitt Mitchell

Baker

Calhoun Dougherty Clay

Early

Miller

Seminole

Decatur Grady Thomas Brooks Lowndes

Lanier

Echols

Clinch Charlton Camden

Irwin

Wheeler

Toombs

Tattnall

Evans Bryan

Long

Wayne

Appling Jeff Davis

Telfair Liberty

McIntosh

Chatham

Montgomery

Taylor Crawford Bibb

Twiggs

Wilkinson

Johnson

Emanuel

Treutlen Laurens Bleckley

Houston

Peach

Jenkins Screven

Effingham

Bulloch Candler

Burke Glascock

Dade

Walker

Catoosa

Whitfield

Murray

Fannin

Gilmer

Union

Towns Rabun

Stephens Habersham

White

Dawson

Lumpkin

Pickens Gordon Chattooga

Floyd

Bartow

Cherokee

Forsyth

Hall

Banks

Franklin Hart

Madison Elbert Jackson

Barrow

Gwinnett

DeKalb Fulton

Cobb

Paulding

Polk

Haralson

Carroll Douglas

Clayton

Fayette

Coweta Heard

Henry

Rockdale

Newton

Walton

Morgan

Oconee

Clarke Oglethorpe

Wilkes Lincoln

Columbia

Baldwin Jones Monroe Lamar Pike Meriwether

Troup

Harris Talbot

Upson

McDuffie

Warren

Hancock Jasper Putnam

Spalding Butts

Taliaferro

Greene

12Z001

13FF31

13FF31

09FF18

11AA01

09G003

13M007

07H003

32L017

33D072

34H515

34J082

35P094

37P116

38Q208

39Q029

33H208 34H492

07H003

EXPLANATION

N

Extent of surficial aquifer system

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water-level 

rise > 0.01 foot per year

Downward trend—Water-level 

decline > 0.01 foot per year

Atlantic Ocean

0 25 50 MILES

0 25 50 KILOMETERS

Base modified from U.S. Geological Survey 

1:5,000,000-scale digital data

Groundwater Conditions 15

Site name County Year monitoring

began

Water-level trend, in feet, per year1

Period of record From 2008 to 2009

33D072 Camden 1998 0.41 0.88

35P094 Chatham 1942 <.01 0.94

37P116 Chatham 1984 <.01 0.12

38Q208 Chatham 1998 –0.01 0.65

39Q029 Chatham 1998 –0.01 0.79

09FF18 Cobb 2001 –0.10 –0.38

09G003 Decatur 1980 –0.04 1.27

33H208 Glynn 1985 0.15 1.05

34H492 Glynn 1999 0.08 0.88

34H515 Glynn 2005 0.03 0.24

34J082 Glynn 2002 –0.08 0.40

13FF31 Gwinnett 2003 –0.33 1.21

12Z001 Lamar 1967 –0.07 1.23

07H003 Miller 1980 0.02 –0.08

11AA01 Spalding 1943 –0.01 2.85

32L017 Wayne 1983 –0.15 0.39

13M007 Worth 1980 <.01 0.39

1

See appendix for summary statistics.
Well 32L016 (Upper Brunswick aquifer—Wayne County, Georgia)

Brunswick aquifer

Well 34H437 (Upper Brunswick aquifer—Glynn County, Georgia)

–5

–10

0

5

10

1982198519901995200020052009

 48

 50

 52

 54

 56

 58

 60

Well 31U009 (Bulloch County, Georgia) Monitoring began 1983 Monitoring began 1983

Monthly mean water level below and above (–) land surface, in feet

 70

 75

 80

 85

 90

 95

Blank

where

data are

missing

Trend

16 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Brunswick Aquifer System

Water levels in 19 wells were used to define conditions 

during 2008–2009 in the Brunswick aquifer system. The 

aquifer system consists of the upper and lower Brunswick 

aquifers and equivalent low-permeability sediments to the 

north and west in southeastern Georgia, which are confined 

throughout the known area of extent (map and table, facing 

page). Water-level fluctuations reflect changes in local 

pumping, interaquifer-leakage effects, and recharge. Waterlevel hydrographs for selected wells (below) illustrate monthly 

mean water levels for the period of record. The hydrographs 

show periodic upward or downward trends that reflect surplus 

or deficits in rainfall, respectively, and changes in pumping.

During the period of record, water levels in 11 of the 

19 wells have remained the same or have been rising at rates 

of 0.02 to 2.25 feet per year (ft/yr). Water levels in eight wells 

declined at rates of 0.06 to 0.94 ft/yr during the period of 

record. During 2008–2009, water levels in 17 wells rose at 

rates of 0.05 to 2.30 ft/yr, which reflects recovery from the 

drought that ended in late 2008. Water levels in two wells 

declined from 0.08 to 0.37 ft/yr. The reason for the declining 

levels in these two wells is unknown but may be related to 

local variations in pumping 
Atlantic Ocean

31U009

35T005

35S008

34S008

35Q050

39Q026

33D071

34J077

34J080

34J081

35H077 34H437

36N012

32L016

32G047

33J062

33J065

38Q209

34K104

Bacon

Brantley

Pierce

Ware

Charlton Camden

Toombs

Tattnall

Evans

Bryan

Long

Wayne

Appling

Liberty

McIntosh

Chatham

Effingham

Bulloch Candler

Glynn

0

0 20 KILOMETERS 10

10 20 MILES

Base from U.S. Geological Survey 

1:100,000-scale digital data

N

GEORGIA

EXPLANATION

Approximate extent of 

 Brunswick aquifer system

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

Downward trend—Water level 

decline > 0.01 foot per year

35S008

38Q209

Groundwater Conditions 17

Site name

Waterbearing

unit1

County

Year 

monitoring

began

Water-level trend,

 in feet per year2

Period of 

record

From 2008 

to 2009

36N012 L Bryan 1999 0.16 1.72

31U009 UX Bulloch 1982 –0.52 1.05

32G047 U Camden 2004 –0.91 1.03

33D071 U Camden 1998 2.25 0.62

35Q050 U Chatham 2001 0.26 0.97

38Q209 B Chatham 1998 0.06 –0.08

39Q026 UX Chatham 1996 0.02 0.06

34S008 LX Effingham 2001 0.20 1.72

35S008 LX Effingham 2000 0.27 1.02

35T005 UX Effingham 2000 0.23 1.11

33J062 L Glynn 2001 <.01 –0.37

33J065 U Glynn 2001 <.01 0.32

34H437 U Glynn 1983 0.16 0.52

34J077 U Glynn 1998 –0.94 2.30

34J080 L Glynn 2002 –0.52 1.46

34J081 U Glynn 2002 –0.16 1.30

35H077 L Glynn 2005 –0.06 1.59

34K104 L McIntosh 2005 –0.40 1.06

32L016 U Wayne 1983 –0.19 0.05

1

L, lower Brunswick aquifer; UX, undifferentiated, low-permeability 

equivalent to the upper Brunswick aquifer; U, upper Brunswick aquifer; 

B, Brunswick aquifer system; LX, undifferentiated, low-permeability 

equivalent to the lower Brunswick aquifer. 

2

See appendix for summary statistics.
18 Groundwater Conditions and Studies in Georgia, 2008–2009

South-central area. Six counties constitute the southcentral area. In this area, the Upper Floridan aquifer ranges 

in thickness from about 300 to 700 ft (Miller, 1986). 

Lowndes County is a karst region with abundant sinkholes 

and sinkhole lakes that have formed where the aquifer crops 

out and the overlying confining unit has been removed by 

erosion (Krause, 1979). Direct recharge from rivers to the 

Upper Floridan aquifer occurs through these sinkholes at 

a rate of about 70 Mgal/d (Krause, 1979). In the south-central 

area, groundwater use totaled about 91 Mgal/d in 2005, and 

most of this withdrawal was used for irrigation (Fanning 

and Trent, 2009).

East-central area. Four counties constitute the eastcentral area. In this area, the Upper Floridan aquifer can 

be as thick as 650 ft in the southeast or absent in the north. 

In the east-central area, groundwater withdrawal totaled 

about 15 Mgal/d during 2005 and was used predominantly 

for irrigation (Fanning and Trent, 2009).

Coastal area. The Georgia Environmental Protection 

Division (GaEPD) defines the coastal area of Georgia as 

a 24-county area that includes 6 coastal counties and the 

adjacent 18 counties—an area of about 12,240 square miles. 

In the coastal area, the Upper Floridan aquifer may be thin 

or absent in the north (Burke County) to about 1,700 ft 

thick in the south (Ware County; Miller, 1986). Excluding 

withdrawals for thermoelectric-power generation, nearly 

70 percent of all withdrawals in the area are from groundwater, primarily for industrial purposes. During 2005, 

about 308 Mgal/d of water was withdrawn from the Upper 

Floridan aquifer in the coastal area (Fanning and Trent, 2009). 

The coastal area of Georgia has been subdivided by 

GaEPD into three subareas—the northern, central, and 

southern—to facilitate implementation of the State’s watermanagement policies. The central subarea includes the largest 

concentration of pumpage in the coastal area of the Savannah, 

Brunswick, and Jesup pumping centers. The northern subarea 

is northwest of the Gulf Trough (Herrick and Vorhis, 1963), 

a prominent geologic feature that is characterized by a 

zone of low permeability in the Upper Floridan aquifer that 

inhibits flow between the central and northern subareas. In 

these two subareas, pumping from the aquifer primarily is 

for agricultural use, and no large pumping centers are located 

in the area. The southern subarea is separated from the central 

subarea by the Satilla line, a postulated hydrologic boundary 

(W.H. McLemore, Georgia Environmental Protection 

Division, Geologic Survey Branch, oral commun., 2000). 

In this area, the largest pumping center is at Fernandina Beach, 

Nassau County, Florida.

Groundwater Levels 

Upper Floridan Aquifer

The Upper Floridan aquifer underlies most of the Coastal 

Plain of Georgia, southern South Carolina, extreme southeastern 

Alabama, and all of Florida (Miller, 1986). The aquifer is 

one of the most productive in the United States and a major source 

of water in the region. During 2005, about 658 million gallons 

per day (Mgal/d) were withdrawn from the Upper and 

Lower Floridan aquifers in Georgia, primarily for industrial 

and irrigation uses (Fanning and Trent, 2009). 

The Upper Floridan aquifer predominately consists of 

Eocene to Oligocene limestone, dolomite, and calcareous 

sand. The aquifer is thinnest along its northern limit (map, 

facing page) and thickens to the southeast, where the 

maximum thickness is about 1,700 feet (ft) in Ware County, 

Georgia (Miller, 1986). The aquifer is confined throughout 

most of its extent, except where it crops out or is near land 

surface along the northern limit, and in karst areas in parts 

of southwestern and south-central Georgia.

The Coastal Plain of Georgia has been divided 

informally into four hydrologic areas for discussion of 

water levels (map, facing page)—the southwestern, southcentral, east-central, and coastal areas. This subdivision is a 

modification of that used by Peck and others (1999) and is 

similar to that used by Clarke (1987). 

Southwestern area. All or parts of 16 counties constitute 

the southwestern area. In this area, the Upper Floridan 

aquifer ranges in thickness from about 50 ft in the northwest 

to about 475 ft in the southeast (Hicks and others, 1987). 

The aquifer is overlain by sandy clay residuum, which is 

hydraulically connected to streams. Since the introduction 

of center-pivot irrigation systems around 1975, the Upper 

Floridan aquifer has been widely used as the primary water 

source for irrigation in southwestern Georgia (Hicks and 

others, 1987). According to Fanning and Trent (2009), about 

314 Mgal/d of water was withdrawn from the Upper Floridan 

aquifer in the southwestern area during 2005, and 80 percent 

of this amount was used for irrigation. 

The City of Albany–Dougherty County lies in the 

southwestern area of Georgia. During 2005, most of the 

water withdrawn from the Upper Floridan aquifer in this area 

was used for public-supply (about 14 Mgal/d) and industry 

(14 Mgal/d; Fanning and Trent, 2009).
Brantley

Camden

FL

GA

Atlantic Ocean

? ?

NORTHERN

FLORIDAN AQUIFERS

LIMIT

APPROXIMATE

UPPER AND LOWE

Fall

R

Line

Richmond

Jefferson

Washington

Muscogee

Chattahochee

Marion

Schley

Macon

Dooly Pulaski Dodge

Wilcox Crisp

Webster

Sumter

Stewart

Quitman

Terrell Lee

Worth

Turner Ben Hill

Coffee Bacon

Glynn

Pierce

Ware

Berrien Atkinson

Cook

Tift

Colquitt Mitchell

Baker

Calhoun Clay

Early

Miller

Seminole

Decatur Grady Thomas Brooks Lowndes

Lanier

Echols

Clinch Charlton

Nassau

Irwin

Toombs

Tattnall

Evans Bryan

Long

Wayne

Appling Jeff Davis

Telfair Liberty

McIntosh

Chatham

Crawford

Taylor

Bibb

Twiggs

Wilkinson Johnson

Emanuel

Bleckley

Houston

Peach

Jenkins Screven

Effingham

Bulloch Candler

Burke

Glascock

Dade

Walker

Catoosa Whitfield

Murray

Fannin

Gilmer

Union

Towns Rabun

Stephens Habersham

White

Lumpkin

Dawson

Pickens Chattooga Gordon

Floyd Bartow Cherokee Forsyth

Hall Banks Franklin Hart

Madison Elbert Jackson

Barrow Gwinnett

DeKalb Fulton

Cobb Paulding

Polk

Haralson

Carroll

Douglas

Fayette

Clayton

Coweta Heard

Henry

Rockdale

Newton

Walton

Morgan

Oconee

Clarke Oglethorpe

Wilkes Lincoln

Columbia

Jones Baldwin Monroe Pike Lamar Meriwether

Troup

Harris Talbot

Upson

McDuffie

Warren

Hancock Jasper Putnam Butts Spalding

Taliaferro Greene

Dougherty

Randolph

Wheeler

Montgomery

Treutlen Laurens

Savannah

Brunswick

Fernandina 

Beach

Albany Jesup

GEORGIA

GEORGIA

Upper

Floridan

aquifer

EXPLANATION

South central

AREAS OF THE UPPER FLORIDAN 

 AQUIFER REFERRED TO 

 IN THIS REPORT

East central

Southwestern

GULF TROUGH

SATILLA LINE

City of Albany–

 Dougherty County

Coastal

Northern

Central

Southern

0 25 50 MILES

0 25 50 KILOMETERS

Base modified from 

U.S. Geological Survey 

1:5,000,000-scale digital data

N

Groundwater Conditions 19

ground water in the Upper Floridan aquifer, Albany 

area, Georgia: U.S. Geological Survey Water-Resources 

Investigations Report 87–4145, 52 p; available online at 

http://pubs.usgs.gov/wri/wri87-4145/.

Krause, R.E., 1979, Geohydrology of Brooks, Lowndes, and 

western Echols Counties, Georgia: U.S. Geological Survey 

Water-Resources Investigations Report 78–117, 48 p.

Miller, J.A., 1986, Hydrogeologic framework of the Floridan 

aquifer system in Florida and parts of Georgia, Alabama, 

and South Carolina: U.S. Geological Survey Professional 

Paper 1403-B, 91 p.

Peck, M.F., Clarke, J.S., Ransom, III, Camille, and 

Richards, C.J., 1999, Potentiometric surface of the Upper 

Floridan aquifer in Georgia and adjacent parts of Alabama, 

Florida and South Carolina, May 1998, and water-level 

trends in Georgia, 1990–98: Georgia Department of Natural 

Resources, Environmental Protection Division, Georgia 

Geologic Survey, Hydrologic Atlas 22, 1 pl.

References

Clarke, J.S., 1987, Potentiometric surface of the Upper 

Floridan aquifer in Georgia, May 1985, and water-level 

trends, 1980–85: Georgia Geologic Survey Hydrologic 

Atlas 16, scale 1:1,000,000, 1 sheet.

Fanning, J.L., and Trent, V.P., 2009, Water use in Georgia 

by county for 2005; and water-use trends, 1980–2005: 

U.S. Geological Survey Scientific Investigations Report 

2009–5002, 186 p.; available online at http://pubs.usgs.gov/

sir/2009/5002/.

Herrick, S.M., and Vorhis, R.C., 1963, Subsurface geology 

of the Georgia Coastal Plain: Georgia Department of 

Natural Resources, Division of Mines, Mining, and 

Geology, Information Circular 25, 80 p.

Hicks, D.W., Gill, H.E., and Longsworth, S.A., 1987, 

Hydrogeology, chemical quality, and availability of 

Areas of the Upper Floridan aquifer referred to in this report.
Well 09F520 (Decatur County, Georgia)

Well 13J004 (Mitchell County, Georgia)

Well 08K001 (Early County, Georgia)

Blank

where

data are

missing

0

 10

 –10

 20

 30

40

 35

 40

 45

 50

 55

Upper Floridan

Southwestern area

Monitoring began 1979

Monitoring began 1978

Monthly mean water level below and above (–) land surface, in feet

 35

 40

 45

 50

 55

 60

1969197019751980

1985

1990

1995

2000

2005

2009

Trend

20 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Upper Floridan Aquifer

Southwestern Area

Water levels in 18 wells were used to define ground

water conditions in the Upper Floridan aquifer in southwestern Georgia during 2008–2009 (map and table, facing 

page). In this area, water in the Upper Floridan aquifer 

typically is confined; however, in areas where no sediments 

overlie the aquifer (typically to the north and west), water is 

unconfined. Water levels in this area are affected by changes 

in precipitation and pumping. Hydrographs for selected wells 

(below) illustrate monthly mean water levels for the period of 

record. The hydrographs show periodic upward or downward 

trends that reflect surplus or deficits in rainfall, respectively, 

and changes in pumping.

During the period of record, water levels in 11 wells 

had declining trends of 0.05 to 0.73 foot per year (ft/yr), 

and 7 wells had rising trends of 0.01 to 0.38 ft/yr. During 

2008–2009, water levels in 17 of the wells rose 0.37 to 

6.02 ft/yr, which reflect recovery from the drought that ended 

in late 2008. One well (08E039), however, had a declining 

trend of 0.48 ft/yr.
GEORGIA

EXPLANATION

Southwestern area

Upper Floridan aquifer

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

Downward trend—Water level 

Base modified from decline > 0.01 foot per year

U.S. Geological Survey 

1:100,000-scale digital data

N

0 10 20 MILES

0 10 20 KILOMETERS

08E039

11J012

Dooly

Crisp

Sumter

Terrell Lee

Dougherty

(see Albany area)

Mitchell

Baker

Calhoun

Early

Clay

Randolph

Miller

Seminole

Decatur Grady

10G313

09F520

08E038

08E039

09G001

06F001

13J004 11J012

08K001

08G001

06G006

10H009

10K005

12K014

12M017

15Q016

12F036

07H002

Groundwater Conditions 21

Site name County Year monitoring

began

Water-level trend, in feet, per year1

Period of record From 2008 to 2009

10H009 Baker 1998 0.33 4.53

12K014 Baker 1982 –0.09 2.03

10K005 Calhoun 1983 –0.09 1.19

15Q016 Crisp 2002 –0.73 1.78

08E038 Decatur 2001 0.12 0.37

08E039 Decatur 2002 0.01 –0.48

09F520 Decatur 1972 –0.06 2.03

09G001 Decatur 1980 –0.07 2.04

06G006 Early 1982 –0.05 5.06

08K001 Early 1982 0.08 2.22

12F036 Grady 1971 0.26 2.30

12M017 Lee 1982 0.06 0.86

07H002 Miller 1980 0.38 3.29

08G001 Miller 1977 –0.11 6.02

10G313 Mitchell 1976 –0.08 2.91

11J012 Mitchell 1981 –0.06 1.95

13J004 Mitchell 1978 –0.20 2.82

06F001 Seminole 1979 –0.10 4.41

1

See appendix for summary statistics.
Well 11K003 (Dougherty County, Georgia)

City of Albany 

Well 12L029 (Dougherty County, Georgia)

Well 13L049 (Dougherty County, Georgia)

Monthly mean water level below land surface, in feet

Blank

where

data are

missing

Trend

Monitoring began 1982

Monitoring began 1985

 10

 15

 20

 25

 30

 35

 40

 45

 15

 20

 25

 30

 35

 40

 45

19791985

2000

2009

 25

 30

 35

 40

 45

 50

 55

 60

1980

1990

1995

2005

22 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Upper Floridan Aquifer

City of Albany–Dougherty County Area

Water levels in 12 wells were used to define groundwater 

conditions in the Upper Floridan aquifer near Albany, Georgia, 

during 2008–2009 (Dougherty County map and table, facing 

page). Water levels in this area are affected by changes in 

precipitation and pumping. Hydrographs for selected wells 

(below) illustrate monthly mean water levels for the period of 

record. The hydrographs show periodic upward or downward 

trends that reflect surplus or deficits in rainfall, respectively, 

and changes in pumping.

During the period of record, water levels in 9 of the 

12 wells had declining trends of 0.03 to 0.36 foot per year 

(ft/yr); the remaining 3 wells had rising trends of 0.07 to 

0.10 ft/yr. During 2008–2009, water levels in all of the wells 

rose from 1.86 to 7.33 ft/yr, which reflect recovery from the 

drought that ended in late 2008.

In addition to continuous water-level monitoring, 

synoptic water-level measurements are made periodically 

in wells southwest of Albany. Water-level measurements 

from 81 wells during November 2008 and 64 wells during 

November 2009 were used to construct maps showing 

the potentiometric surface of the Upper Floridan aquifer. 

Although water levels in 2009 generally were higher than 

in 2008, the configuration of the potentiometric surface 

maps (facing page) was similar. The potentiometric-surface 

maps show that water generally flows from northwest to 

southeast toward the Flint River. In the southeastern part 

of the mapped area, flow was away from the river toward 

the southwest.

Reference

Gordon, D.W., 2009, Groundwater conditions and studies 

in the Albany area of Dougherty County, Georgia, 2008:

U.S. Geological Survey Open-File Report 2009–1244, 54 p.; 

available online at http://pubs.usgs.gov/of/2009/1244/.
Dougherty County

0 2 4 6 MILES

0 2 4 6 KILOMETERS

N

13L012

13K014

12L370

13L049

12L277

12K141

13L180

Area of enlarged map

12L030

12L029

11K003

12L373

12K180

11K003

GEORGIA

EXPLANATION

City of Albany–Dougherty County area

Upper Floridan aquifer

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

160

150

170

140

150

210

200

190

180

170

160

150

140

150

155

Well data point

150

EXPLANATION

Potentiometric contour—Shows altitude at which water level would 

have stood in tightly cased wells. Dashed where approximately 

located. Hachures indicate depression. Contour interval 10 feet. 

Datum is National Geodetic Vertical Datum 1929 (November 2008 

map modified from Gordon, 2009)

Direction of groundwater flow

Base modified from U.S. Geological Survey

1:24,000-scale digital data

0 1 2 3 MILES

0 1 2 3 KILOMETERS

Well field

DOUGHERTY COUNTY

TERRELL COUNTY LEE COUNTY

DOUGHERTY 

COUNTY BAKER COUNTY

82 19

234

62

91

19

82

234

62

91

Flint

Cooleewahee Creek

River

Kiokee

November 2008

November 2009

Creek

Albany

County Line Rd

Old Pretoria

Rd

Vanderbilt Dr

Hard Up Rd

River Rd

Flint

Cooleewahee Creek

River

Well field

Kiokee Creek

84°20' 84°15' 84°10'

31°35'

31°30'

Groundwater Conditions 23

Site name County

Year 

monitoring

began

Water-level trend, 

in feet, per year1

Period of 

record

From 2008 

to 2009

11K003 Dougherty 1982 –0.11 6.39

12K141 Dougherty 1996 –0.36 7.33

12K180 Dougherty 2002 –0.15 2.78

12L029 Dougherty 1982 0.10 2.39

12L030 Dougherty 1985 –0.06 3.81

12L277 Dougherty 2000 0.07 6.43

12L370 Dougherty 2000 0.07 3.32

12L373 Dougherty 2002 –0.16 3.27

13K014 Dougherty 1982 –0.11 1.86

13L012 Dougherty 1978 –0.04 2.14

13L049 Dougherty 1985 –0.11 3.35

13L180 Dougherty 1996 –0.03 2.83

1

See appendix for summary statistics.
0 10 20 MILES

0 10 20 KILOMETERS

Base modified from 

U.S. Geological Survey

1:100,000 digital data

N

Cook

Tift

Colquitt

Thomas Brooks

Lowndes

Worth

Upper Floridan aquifer

EXPLANATION

South-central area

Observation well, site name, and 2008–2009 water-level trend

Upward trend—Water level rise > 0.01 foot per year

Downward trend—Water level decline > 0.01 foot per year

Flint Riv er

Flint River

GEORGIA

18H016

18K049

19E009

15L020

15L020

13M006

13M006

24 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Upper Floridan Aquifer

South-Central Area

Water levels in five wells were used to define ground

water conditions in the Upper Floridan aquifer in south-central 

Georgia during 2008–2009 (map and table below). In this 

area, water in the Upper Floridan aquifer generally is confined 

but locally is unconfined in karst areas in Lowndes County. 

Water levels in this area are affected by changes in pumping 

and by precipitation, with climatic effects more pronounced 

in areas where the aquifer is close to land surface, such as the 

karst area in Lowndes County and near the Flint River in the 

northwestern part of Worth County. 

Hydrographs for selected wells (facing page) illustrate 

monthly mean water levels for the period of record. In 

Lowndes County, water-level fluctuations in well 19E009 

show a pronounced response to climatic effects because the 

well is in a karst area. Climatic effects are less pronounced in 

the other three wells, and water levels primarily are influenced 

by pumping. The hydrographs show periodic upward or 

downward trends that reflect surplus or deficits in rainfall, 

respectively, and changes in pumping.

During the period of record, water levels in all five of 

the wells monitored in the south-central area declined 0.10 to 

0.87 foot per year (ft/yr). The greatest declines were in Tift, 

Cook, and Worth Counties in the northern and eastern part 

of the area, where recharge is limited by low permeability 

overburden and irrigation pumping is high (Torak and others, 

2010). The rate of decline was lower in wells located near 

areas of recharge in Lowndes County (well 19E009) and near 

the Flint River in northwestern Worth County (well 13M006). 

During 2008–2009, water levels in three of the five wells rose 

at rates ranging from 1.37 to 2.83 ft/yr, which reflect recovery 

from the drought that ended in late 2008. Despite the end 

of the drought, however, water levels in wells 15L020 and 

18K049 continued to decline at rates of 0.76 and 0.03 ft/yr, 

respectively, which reflect the restricted recharge and influence 

of continued pumping in the area.

Reference

Torak, L.J., Painter, J.A., and Peck, M.F., 2010, Geohydrology of the Aucilla–Suwannee–Ochlockonee 

River basin, south-central Georgia and adjacent parts of 

Florida: U.S. Geological Survey Scientific Investigations 

Report 2010–5072, available online at http://pubs.usgs.gov/

sir/2010/5072/.

Site name County

Year 

monitoring

began

Water-level trend, 

in feet, per year1

Period of 

record

From 2008 

to 2009

18H016 Cook 1971 –0.32 1.37

19E009 Lowndes 1957 –0.12 2.83

18K049 Tift 1978 –0.87 –0.03

13M006 Worth 1980 –0.10 1.62

15L020 Worth 1972 –0.67 –0.76

1

See appendix for summary statistics.
Upper Floridan Aquifer

South-Central area

Well 18K049 (Tift County, Georgia)

Well 13M006 (Worth County, Georgia)

Well 19E009 (Lowndes County, Georgia)

Well 15L020 (Worth County, Georgia) 190

 195

 200

 205

 210

 215

 220

Monitoring began 1964

Monitoring began 1972

Monitoring began 1978

Blank

where

data are

missing

Trend

Monitoring began 1980

19571960

1965197019751980

1985

1990

1995

2000

2005

2009

 100

 110

 120

 130

 140

 150

 160

 165

 170

 175

 180

 185

 110

 120

 130

 140

 150

 160

Well 18H016 (Cook County, Georgia)

0

 10

–10

 20

 30

40

Monthly mean water level below and above (–) land surface, in feet

Groundwater Conditions 25
Upper Floridan aquifer

East-Central area

Well 21T001 (Laurens County, Georgia)

Well 25Q001 (Montgomery County, Georgia)

Monthly mean water level below land surface, in feet

Monitoring began 1966 Blank

where

data are

missing

19641965197019751980198519901995200020052009

 60

 70

 80

 90

 100

 22

 26

 30

 34

 38

 42

Trend

26 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Upper Floridan Aquifer

East-Central Area

Water levels in two wells were used to define groundwater conditions in the Upper Floridan aquifer in east-central 

Georgia during 2008–2009 (map and table, facing page). In 

this area, water in the Upper Floridan aquifer is confined in 

the southeast and is semiconfined in the northwest, and water 

levels are influenced by climatic effects and agricultural 

pumping in these areas. Hydrographs for the two wells 

(below) illustrate monthly mean water levels for the period of 

record. The hydrographs show periodic upward or downward 

trends that reflect surplus or deficits in rainfall, respectively, 

and changes in pumping.

During the period of record, water levels in both wells 

showed a long-term decline, ranging from 0.06 foot per 

year (ft/yr) in well 21T001 to 0.58 ft/yr in well 25Q001. 

During 2008–2009, water levels in well 21T001 continued 

to show a slight decline (0.18 ft/yr), whereas water levels 

in well 25Q001 rose 2.39 ft/yr. These variations in waterlevel response may be related to differences in proximity 

to available recharge and to local pumping changes. Well 

21T001 in Laurens County is in the northwestern part of 

the area where the aquifer is semiconfined and close to the 

area of recharge. Well 25Q001 in Montgomery County is in 

an area where the aquifer is deeply buried and confined and 

is more isolated from recharge sources. Local and regional 

pumping have a more pronounced effect on water levels in 

well 21T001, which may account for the larger rate of change 

observed during the period of record and 2008–2009. 
0 10 20 MILES

0 10 20 KILOMETERS

Base modified from 

U.S. Geological Survey

1:100,000-scale digital data N

Wheeler Montgomery

Treutlen

Laurens

21T001

21T001 25Q001

25Q001

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

Downward trend—Water level 

decline > 0.01 foot per year

EXPLANATION

East-central area

Upper Floridan aquifer

GEORGIA

Groundwater Conditions 27

Site name County Year monitoring

began

Water-level trend, in feet, per year1

Period of record From 2008 to 2009

21T001 Laurens 1964 –0.06 –0.18

25Q001 Montgomery 1966 –0.58 2.39

1

See appendix for summary statistics.
Upper Floridan aquifer

Northern Coastal area

Well 26R001 (Toombs County, Georgia)

Well 31U008 (Bulloch County, Georgia) Monitoring began 1983

Monthly mean water level below land surface, in feet

Trend

 70

 75

 80

 85

 90

 95

 100

 150

 160

 170

 180

 190

1974

1975

198019851990199520002005

2009

Blank

where

data are

missing

28 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Upper Floridan Aquifer

Northern Coastal Area

Water levels in two wells were used to define ground

water conditions in the Upper Floridan aquifer in the northern 

coastal area during 2008–2009 (map and table, facing page). 

In this area, water in the Upper Floridan aquifer is confined 

to the southeast and is semiconfined to the northwest, and 

water levels are influenced by climatic effects and agricultural 

pumping in these areas. Hydrographs for the two wells 

(below) illustrate monthly mean water levels for the period of 

record. The hydrographs show periodic upward or downward 

trends that reflect surplus or deficits in rainfall, respectively, 

and changes in pumping.

During the period of record, water levels declined at rates 

of 0.54 foot per year (ft/yr) in well 31U008 and 0.79 ft/yr 

in well 26R001. During 2008–2009, water levels declined 

at an accelerated rate of 1.13 ft/yr in well 31U008, whereas 

water levels in well 26R001 rose at a rate of 0.92 ft/yr. These 

variations likely resulted from changes in nearby pumping.
26R001

31U008

26R001

Tattnall

Evans

Emanuel

Jenkins

Screven

Effingham

Bulloch

Candler

Burke

Toombs

EXPLANATION

0 10 20 MILES

0 10 20 KILOMETERS

Base from U.S. Geological Survey 

1:100,000-scale digital data

Upper Floridan aquifer

Northern coastal area 

31U008

N Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

Downward trend—Water level 

decline > 0.01 foot per year

GEORGIA

Groundwater Conditions 29

Site name County Year monitoring

began

Water-level trend, in feet, per year1

Period of record From 2008 to 2009

31U008 Bulloch 1983 –0.54 –1.13

26R001 Toombs 1974 –0.79 0.92

1

See appendix for summary statistics.
Well 32L015 (Wayne County, Georgia)

Upper Floridan aquifer

Central Coastal area

Well 33M004 (Long County, Georgia)

Well 36Q008 (Chatham County, Georgia) Monitoring began 1968

Monitoring began 1982

Monthly mean water level below land surface, in feet

Blank

where

data are

missing

Trend

1954

1955

196019651970

197519801985

1990199520002005

2009

 60

 70

 80

 90

 100

 110

 120

 130

 30

 35

 40

 45

 50

 55

 60

 65

 50

 52

 54

 56

 58

 60

 62

 64

 66

30 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Upper Floridan Aquifer

Central Coastal Area

Water levels in 16 wells were used to define groundwater conditions in the Upper Floridan aquifer in the central 

coastal area of Georgia (excluding the Brunswick area of 

Glynn County) during 2008–2009 (map and table below). In 

this area, water in the Upper Floridan aquifer is confined and 

primarily influenced by pumping. Hydrographs for selected 

wells (below) illustrate monthly mean water levels for the 

period of record. The hydrographs show periodic upward or 

downward trends that reflect changes primarily in pumping. 

During the period of record, water levels in 11 of the 

16 wells declined 0.04 to 1.49 feet per year (ft/yr). Water 

levels in the remaining five wells rose at rates of 0.05 to 

1.5 ft/yr. During 2008–2009, water levels in all 16 wells rose 

at rates ranging from 0.72 to 5.88 ft/yr, which reflect reduced 

water use in the coastal area as the result of conservation 

practices and recovery from the drought that ended in 

late 2008. 

The hydrograph for well 36Q008 near Savannah in 

Chatham County shows an overall downward trend of 

0.16 ft/yr in water levels for the period of record. Since 1991, 

however, water levels have been rising in the well, largely 

as the result of decreased water use due to conservation 

practices in the area (J.L. Fanning, U.S. Geological Survey, 

oral commun., 2008). This rising trend continued during 

2008–2009 when water levels in well 36Q008 rose 4.72 ft/yr.
38Q002

37Q185

39Q003

37Q016

35T003

35M013

34N089 37P114

35P110

32L015

34G033

30L003

33M004

36Q008

36Q020

39Q025

Glynn

Tattnall

Evans

Bryan

Long

Wayne

Appling Liberty

McIntosh

Chatham

Bulloch

Effingham

See 

City of

Brunswick

area

Candler

Toombs

Upper Floridan aquifer

Central coastal area

EXPLANATION

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

N

0 10 20 MILES

0 10 20 KILOMETERS

Base from U.S. Geological Survey 

1:100,000-scale digital data

30L003

Atlantic Ocean

Savannah GEORGIA

Groundwater Conditions 31

Site name County Year monitoring

began

Water-level trend, in feet, per year1

Period of record From 2008 to 2009

35P110 Bryan 2000 0.05 2.20

36Q008 Chatham 1954 –0.16 4.72

36Q020 Chatham 1958 –0.54 2.75

37P114 Chatham 1984 0.22 3.04

37Q016 Chatham 1955 –0.04 4.40

37Q185 Chatham 1985 1.50 5.88

38Q002 Chatham 1956 –0.27 1.48

39Q003 Chatham 1962 –0.26 0.72

39Q025 Chatham 1996 0.18 1.10

34G033 Glynn 2004 –1.49 1.38

35T003 Effingham 2000 0.23 1.11

34N089 Liberty 1967 –0.49 1.96

33M004 Long 1968 –0.43 1.41

35M013 McIntosh 1966 –0.42 1.68

30L0032 Wayne 1964 –0.46 2.43

32L015 Wayne 1983 –0.18 1.31

1

See appendix for summary statistics. 

2

Well is completed in the Upper and Lower Brunswick aquifers and the Upper Floridan aquifer.
Monthly mean water level below and above (–) land surface, in feet

Upper Floridan Aquifer

City of Brunswick

–15

–10

–5

0

5

 10

–15

–10

–5

0

5

10

–5

0

5

 10

 15

 20

 25

19621965197019751980198519901995200020052009

Well 34H371 (Glynn County, Georgia)

Well 34H334 (Glynn County, Georgia)

Well 33H133 (Glynn County, Georgia) Monitoring began 1967 Monitoring began 1964

Blank

where

data are

missing

Trend

32 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Upper Floridan Aquifer

City of Brunswick Area

Water levels in seven wells were used to define groundwater conditions in the Upper Floridan aquifer near the City 

of Brunswick in the central coastal area of Georgia during 

2008–2009 (maps and table, facing page). In this area, water 

in the Upper Floridan aquifer is confined, and groundwater 

flow paths are influenced primarily by pumping for industrial 

and public supply.

During the period of record, water levels in all of the 

wells had rising trends with rates of change that ranged from 

0.05 to 4.26 feet per year (ft/yr). Hydrographs for three wells 

in the Upper Floridan aquifer in the Brunswick area (below) 

illustrate monthly mean water levels for the period of record. 

During 2008–2009, water levels in the seven wells rose at 

rates ranging from 0.89 to 7.58 ft/yr. 

In addition to continuous water-level monitoring, 

synoptic water-level measurements are made periodically 

in wells in the Brunswick area. Water-level measurements 

from 20 wells were collected during July 2008 and from 

22 wells during July–August 2009, which subsequently were 

used to construct potentiometric-surface maps of the Upper 

Floridan aquifer. The maps on the facing page show that 

groundwater generally flows from the south, where water-level 

altitudes are greater than 15 ft, toward industrial pumping 

centers in northern Brunswick, where water-level altitude is 

less than 0 ft.

References 

Cherry, G.S., Peck, M.F., Painter, J.A., and Stayton, W.L., 

2010, Groundwater conditions and studies in the Brunswick–

Glynn County area, Georgia, 2008: U.S. Geological Survey 

Open-File Report 2009–1275, 54 p.; available online at 

http://pubs.usgs.gov/of/2009/1275/.

Peck, M.F., Painter, J.A., and Leeth, D.C., 2009, Groundwater 

conditions and studies in Georgia, 2006–2007: U.S. Geological 

Survey Scientific Investigations Report 2009–5070, 86 p.; 

available online at http://pubs.usgs.gov/sir/2009/5070/.
5

15

10

0 l l l l l

l l l l l

l l

l l

l

l l l l l l l l l l

Area of

enlarged

map 

GEORGIA

34H334

33H127

33H133

33H207

34H371

33H324

33H325

Glynn County

NEWCASTLE

STREET

STREET

NORWICH

STONEWALL STREET

Andrews

Island

East River

Oglethorpe Bay

TURTLE

RIVER

NEWCASTLE

STREET

STREET

NORWICH

STONEWALL STREET

Andrews

Island

4TH STREET

4TH STREET

East River

Oglethorpe Bay

TURTLE

RIVER

NEWCASTLE

STREET

STREET

NORWICH

STONEWALL STREET

Andrews Island

4TH STREET

East River

Oglethorpe Bay

TURTLE

RIVER

BRUNSWICK

July 2008

15

0 0.5

0 0.5

Base modified from U.S. Geological Survey 1.0 MILE

1:24,000-scale digital data

Brunswick West, Brunswick East 1.0 KILOMETER

N

July–August 2009

General direction of groundwater flow

Observation well

EXPLANATION

Upper Floridan aquifer City of Brunswick area

EXPLANATION

Potentiometric contour—Shows altitude at which water level would have stood in tightly cased 

wells in the Upper Floridan aquifer. Contour interval 5 feet. Hachures indicate depression. Datum 

is North American Vertical Datum of 1988

(Modified from Cherry and others, 2010) 

Observation well, site 

name, and 2008–2009 

water level trend

EXPLANATION

Upward trend— 

Water level 

rise > 0.01 foot 

per year

33H207

15

20

5

5

5

0

10

10

Groundwater Conditions 33

Site name County

Year 

monitoring

began

Water-level trend, 

in feet, per year1

Period of 

record

From 2008 

to 2009

33H127 Glynn 1962 0.05 2.07

33H133 Glynn 1964 0.27 2.43

33H207 Glynn 1986 0.47 0.89

33H324 Glynn 2007 1.73 2.24

33H325 Glynn 2007 4.26 7.58

34H334 Glynn 1985 0.17 1.54

34H371 Glynn 1986 0.14 1.28

1

See appendix for summary statistics.
Well 33E027 (Camden County, Georgia)

Well 27G003 (Ware County, Georgia)

Upper Floridan aquifer

Southern Coastal area

Well 27E004 (Charlton County, Georgia)

Monthly mean water level below and above (–) land surface, in feet

Blank

where

data are

missing

Trend

 90

 100

 95

 105

 110

 62

 64

 66

 68

 70

 72

 74

 76

–35

–20

–10

–25

–30

–15

19781980

19851990

1995

2000

2005

2009

Monitoring began 1979 Monitoring began 1981

34 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Upper Floridan Aquifer

Southern Coastal Area 

Water levels in four wells were used to define groundwater conditions in the Upper Floridan aquifer in the southern 

coastal area of Georgia during 2008–2009 (map and table, 

facing page). In this area, water in the Upper Floridan aquifer 

is confined and influenced mostly by pumping to the south in 

the Fernandina Beach area, Florida, and by climatic effects 

and pumping to the west. Hydrographs for selected wells 

(below) illustrate monthly mean water levels for the period 

of record. The hydrographs show periodic upward or downward trends that primarily reflect changes in pumping. The 

sharp rise in water levels in late 2002 on each of the hydrographs is the result of a 35 million gallons per day decrease 

in pumpage at a nearby industry in St. Marys (Peck and 

others, 2005).

Water-level changes during the period of record varied 

across the southern coastal area. In the western part of the 

area, water levels declined at rates of 0.12 to 0.21 foot per year 

(ft/yr). In the eastern part of the area, water levels rose at rates 

of 0.13 to 1.74 ft/yr. The larger water-level rises in the eastern 

part of the area result from the discontinuation of pumping at 

nearby St. Marys in 2002 (see hydrograph for well 33E027). 

During 2008–2009, water levels in all of the wells rose at rates 

ranging from 0.92 to 1.34 ft/yr, which corresponds to the end 

of a 2-year drought in 2008.

In addition to continuous water-level monitoring, synoptic 

water-level measurements are made periodically, in cooperation 

with the St. Johns River Water Management District, in wells 

in and around the southern coastal area of Georgia and adjacent 

parts of Florida. During September 2008 and May 2009, 

water levels measured in this area were used to construct 

potentiometric-surface maps of the aquifer (Kinnaman and 

Dixon 2009a, b). The maps for 2008 and 2009 (insets, facing 

page) show that water generally flowed from west to east 

toward the Atlantic Ocean and toward pumping centers at 

Fernandina Beach and Jacksonville, Florida. 
GA FL

GA FL

N

20

40

40

30

30

50

30

30

20

10

–10

0

50

30

20

40

30

20

10

0

27E004

33D069

27G003

33E027

EXPLANATION

Potentiometric contour—Shows altitude at which 

water level would have stood in tightly cased 

wells. Hachures indicate depressions. Contour 

interval 10 feet. Datum is North American Vertical 

Datum of 1988 (modified from Kinnaman and 

Dixon, 2009a, b)

Direction of ground-water flow

May 2009

September 2008

40

Base modified from

U.S. Geological Survey

1:100,000-scale digital data 0 5 10 15 KILOMETERS

0 5 10 15 MILES

EXPLANATION

Upper Floridan aquifer Southern coastal area 

N

Base from U.S. Geological Survey 

1:100,000-scale digital data

0 10 20 MILES

0 10 20 KILOMETERS

Observation well, site name, and 2008–2009 water-level trend

27E004 Upward trend—Water level rise > 0.01 foot per year

Area of 

enlarged map

GEORGIA

Atlantic Ocean

Atlantic Ocean

St Marys

Jacksonville

Fernandina

Beach

St Marys

Jacksonville

Fernandina

Beach

Ware

Charlton

Camden

Duval Baker

Nassau

Ware

Charlton

Camden

Duval

Baker

Nassau

Bacon

Brantley

Pierce

Ware

Charlton Camden

Groundwater Conditions 35

References

Kinnaman, S.L., and Dixon, J.F., 2009a, Potentiometric 

surface of the Upper Floridan aquifer in the St. Johns 

River Water Management District and vicinity, Florida, 

September 2008: U.S. Geological Survey Scientific 

Investigations Map 3070, 1 sheet; available online at 

http://pubs.usgs.gov/sim/3070/.

Kinnaman, S.L., and Dixon, J.F., 2009b, Potentiometric 

surface of the Upper Floridan aquifer in the St. Johns River 

Water Management District and vicinity, Florida, May 2009: 

U.S. Geological Survey Scientific Investigations Map 3091, 

1 sheet; available online at http://pubs.usgs.gov/sim/3091/.

Peck, M.F., McFadden, K.W., and Leeth, D.C., 2005, 

Effects of decreased ground-water withdrawal on 

ground-water levels and chloride concentrations 

in Camden County, Georgia, and ground-water levels 

in Nassau County, Florida, from September 2001 

to May 2003: U.S. Geological Survey Scientific 

Investigations Report 2004–5295; 36 p.; available 

online at http://pubs.usgs.gov/sir/2004/5295/.

Site name County

Year 

monitoring

began

Water-level trend, 

in feet, per year1

Period of 

record

From 2008

to 2009

33D069 Camden 1994 1.74 0.92

33E027 Camden 1979 0.13 1.34

27E004 Charlton 1986 –0.12 1.09

27G003 Ware 1984 –0.21 0.98

1

See appendix for summary statistics.
1975

1980

1985

1990

1995

2000

2005

2009

Lower Floridan Aquifers

Well 38Q201 (Chatham County, Georgia)

Well 33H188 (Glynn County, Georgia)

Well 34H391 (Glynn County, Georgia)

Monthly mean water level below and above (–) land surface, in feet

Monitoring began 2000 Monitoring began 2000

Monitoring began 1987

Monitoring began 1978

Blank

where

data are

missing

Trend

–16

–14

–12

–10

–8

–6

–4

–2

 0

–12

–14

–10

–8

–6

–4

–2

0

2

4

 48

 50

 52

 54

 56

 58

Wells 35P109 and 35P125 (Bryan County, Georgia) Well 35P109 Well 35P125 22

 24

 26

 28

 30

 32

 34

 36

Well 33D073 (Camden County, Georgia) –35

–30

–25

–20

–15

–10

–5

0

5

 10

36 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Lower Floridan Aquifer and Underlying Units 

in Coastal Georgia

Water levels in 16 wells in central and southern 

coastal Georgia were used to define groundwater conditions 

in the Lower Floridan aquifer and underlying units during 

2008–2009 (map and table, facing page). In this area, water 

in the Lower Floridan aquifer is confined and influenced 

mostly by pumping. Hydrographs for selected wells (below) 

illustrate monthly mean water levels for the period of record. 

The hydrographs show periodic upward or downward trends 

that primarily reflect changes in pumping.

During the period of record, water levels in 10 of the 

wells rose 0.05 to 2.77 feet per year (ft/yr), and declined 

in 6 wells from 0.06 to 0.46 ft/yr. The largest rise occurred 

in well 33D073 near St. Marys, Camden County, in 

response to the shutdown of an industry in 2002 (Peck 

and others, 2005). 

During 2008–2009, water levels in 14 of the 16 wells 

rose at rates ranging from 1.10 to 2.33 ft/yr, which reflects 

reduced water use in the coastal area as the result of 

conservation practices and recovery from the drought that 

ended in late 2008. Despite this recovery, water levels in 

well 32L005 and 33H188 declined at rates of 0.42 and 

0.83 ft/yr, respectively.
39Q024

38Q201 37Q186

34S011

33R045

35P125

33H206

33D073

33D074

37Q186

32L005

32L005

34H500

34H495

33H188

34H391

34H436

33J044

EXPLANATION

Lower Floridan aquifer

Southern

Central

Coastal area 

Base from U.S. Geological Survey 

1:100,000-scale digital data

0 10 20 MILES

N 0 10 20 KILOMETERS

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level rise 

> 0.01 foot per year

Downward trend—Water level 

decline > 0.01 foot per year

St Marys

Atlantic Ocean

Bacon

Glynn

Brantley

Pierce

Ware

Charlton Camden

Tattnall

Evans

Bryan

Long

Wayne

Appling

Liberty

McIntosh

Chatham

Effingham

Bulloch

Candler

Toombs

GEORGIA

Groundwater Conditions 37

Reference

Peck, M.F., McFadden, K.W., and Leeth, D.C., 2005, 

Effects of decreased ground-water withdrawal on 

ground-water levels and chloride concentrations in 

Camden County, Georgia, and ground-water levels 

in Nassau County, Florida, from September 2001 

to May 2003: U.S. Geological Survey Scientific 

Investigations Report 2004–5295; 36 p.; available 

online at http://pubs.usgs.gov/sir/2004/5295/. 

Site name Water-bearing

unit1 County Year monitoringbegan

Water-level trend, in feet, per year2

Period of record From 2008 to 2009

33R045 LF Bryan 2002 –0.46 1.44

35P109/35P1253 LF Bryan 2000 0.05 1.52

33D073 LF Camden 2000 2.77 1.11

33D074 LF Camden 2003 –0.46 1.10

37Q186 P Chatham 1985 0.67 2.33

38Q201 P Chatham 1987 0.14 1.14

39Q024 LF Chatham 1996 0.17 1.18

34S011 LF Effingham 2002 –0.34 1.14

33H188 F Glynn 1985 –0.08 –0.83

33H206 LF Glynn 1986 0.25 1.54

33J044 LF Glynn 1979 0.09 1.98

34H391 LF Glynn 1984 0.17 1.57

34H436 LF Glynn 1983 0.18 1.46

34H495 LF Glynn 2001 1.22 1.63

34H500 LF Glynn 2001 –0.06 1.90

32L005 LF Wayne 1980 –0.31 –0.42

1

LF, Lower Floridan aquifer; P, Paleocene unit of low permeability; F, Fernandina permeable zone. 

2

See appendix for summary statistics. 

3

Record from 2000–2006 is from well 35P109 that has now been replaced by 35P125.
Well 12L019 (Claiborne aquifer—Dougherty County, Georgia)

Claiborne Aquifer

Well 06K010 (Claiborne aquifer—Early County, Georgia)

Well 32Y033 (Gordon aquifer—Burke County, Georgia)

 72

 74

 76

 78

 80

 60

50

 70

 80

 90

 100

197819791982198519881991199419972000200320062009

–40

–35

–30

–25

–20

–15

–5

–10

Monitoring began 1984

Monitoring began 1995

Monthly mean water level below and above (–) land surface, in feet

Blank

where

data are

missing

Trend

38 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Claiborne and Gordon Aquifers

Water levels in 10 Claiborne aquifer wells and 1 Gordon 

aquifer well were used to define groundwater conditions in 

southwestern and east-central Georgia during 2008–2009 

(map and table, facing page). Water in the Claiborne and 

Gordon aquifers can be confined or unconfined. Hydrographs 

showing water levels in two wells in the Claiborne aquifer 

and one well in the Gordon aquifer (below) illustrate monthly 

mean water levels for the period of record. The hydrographs 

show periodic upward or downward trends that reflect changes 

in precipitation and pumping.

During the period of record, water levels in the 

Claiborne aquifer declined at rates of 0.04 to 1.10 feet per 

year (ft/yr) in 7 of the 10 wells monitored. The greatest decline 

(5.07 ft/yr) in well 12M001 in southern Lee County probably 

is related to increases in local pumping. During 2008–2009, 

water levels in 8 of the 10 Claiborne aquifer wells rose 

from 0.39 to 4.83 ft/yr, which corresponds to the end of a 2-year 

drought in 2008. Despite this overall recovery, however, water 

levels in wells 13L015 and 12M001 in the Claiborne aquifer 

continued to decline at rates of 0.92 and 5.07 ft/yr, respectively.

In the Gordon aquifer, water levels in well 32Y033 

declined at a rate of 1.19 ft/yr for the period of record. During 

2008–2009, water-levels continued to decline at a rate of 

1.35 ft/yr. These declines correspond to increased agricultural 

use in east-central Georgia (Cherry, 2006).

Reference

Cherry, G.S., 2006, Simulation and particle-tracking 

analysis of ground-water flow near the Savannah River Site, 

Georgia and South Carolina, 2002, and for selected watermanagement scenarios, 2002 and 2020: U.S. Geological 

Survey Scientific Investigations Report 2006–5195, 156 p.; 

available online at http://pubs.usgs.gov/sir/2006/5195/.
Base modified from 

U.S. Geological Survey 

1:100,000-scale digital

0 10 20 MILES

0 10 20 KILOMETERS

Marion

Schley

Macon

Dooly

Crisp

Sumter Webster

Stewart

Quitman

Randolph Terrell Lee

Worth

Turner

Mitchell

Baker

Dougherty

Calhoun Clay

Early

Miller

06K010

09M009 13M005

14P015

11P015

11J011

12L019

12M001

13L015

13L011

13M005

12M001

Gordon aquifer

EXPLANATION

Claiborne aquifer

N

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

Downward trend—Water level 

decline > 0.01 foot per year

32Y033 (Burke County) GEORGIA

Groundwater Conditions 39

Site name Water-bearing

unit1 County Year monitoringbegan

Water-level trend, in feet, per year2

Period of record From 2008 to 2009

14P015 C Crisp 1984 –0.31 4.83

12L019 C Dougherty 1978 0.04 3.79

13L011 C Dougherty 1977 0.12 2.63

13L015 C Dougherty 1979 –0.51 –0.92

06K010 C Early 1986 –0.09 1.38

11P015 C Lee 1984 –0.04 1.14

12M001 C Lee 1978 –1.10 –5.07

11J011 C Mitchell 1981 –0.15 3.58

09M009 C Randolph 1984 0.01 1.56

13M005 C Worth 1980 –0.23 0.39

32Y033 G Burke 1995 –1.19 –1.35

1

C, Claiborne aquifer; G, Gordon aquifer. 

2

See appendix for summary statistics.
Well 13L002 (Dougherty County, Georgia)

Clayton aquifer

Well 07N001 (Randolph County, Georgia)

Well 14P014 (Crisp County, Georgia)

Well 11P014 (Lee County, Georgia)

Monthly mean water level below land surface, in feet

Blank

where

data are

missing

Trend Monitoring began 1984 Monitoring began 1984

Monitoring began 1965

 35

 40

 45

 50

 55

60

 130

 140

 150

 160

 170

 180

 20

 40

 60

 80

 100

 120

 140

 160

195719601965

1970

1975

1980

1985

1990

1995

2000

2005

2009

 80

 100

 120

 140

 160

 180

 200

40 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Clayton Aquifer

Water levels in 11 wells were used to define groundwater 

conditions in the Clayton aquifer in southwestern Georgia 

during 2008–2009 (map and table, facing page). In this area, 

water in the Clayton aquifer is confined and influenced mostly 

by pumping. Hydrographs for selected wells (below) illustrate 

monthly mean water levels for the period of record. The 

hydrographs show periodic upward or downward trends that 

reflect changes in pumping.

During the period of record, water levels in 8 of the 

11 wells declined at rates of 0.36 to 1.85 feet per year (ft/yr). 

Water levels rose in three wells at rates from 0.07 to 1.58 ft/yr 

during the period of record. These changes reflect variations 

in local and regional pumping. 

During 2008–2009, water levels in eight of the wells 

rose from 0.32 to 12.48 ft/yr, which corresponds to the end 

of a 2-year drought and the resulting decrease in irrigation in 

2008. The largest rise occurred in well 11P014 in northern 

Lee County and likely results from a decrease in nearby 

pumping. Despite regional recovery from the drought, water 

levels in three of the wells declined from 0.10 to 4.01 ft/yr.
Base modified from 

U.S. Geological Survey 

1:100,000-scale digital

Marion

Schley

Macon

Dooly

Crisp

Sumter Webster

Stewart

Quitman Randolph

Terrell Lee

Worth

Turner

Mitchell

Baker

Dougherty Calhoun

Clay

Early

Miller

0 10 20 MILES

0 10 20 KILOMETERS

14P014

06K009

07N001

11K005

11P014

12M002

12L020 13L002

13L013

13L013

13L002

09M007

11L002

EXPLANATION

Clayton aquifer

N

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

Downward trend—Water level 

decline > 0.01 foot per year

GEORGIA

Groundwater Conditions 41

Site name County Year monitoring

began

Water-level trend, in feet, per year1

Period of record From 2008 to 2009

14P014 Crisp 1986 –0.36 2.01

11K005 Dougherty 1979 –1.64 0.32

11L002 Dougherty 1973 –1.79 5.25

12L020 Dougherty 1980 0.32 –1.98

13L002 Dougherty 1957 –1.62 2.92

13L013 Dougherty 1978 0.07 –4.01

06K009 Early 1986 –1.42 0.10

11P014 Lee 1984 1.58 12.48

12M002 Lee 1978 –0.73 3.71

07N001 Randolph 1965 –0.85 5.54

09M007 Randolph 1984 –1.85 4.16

1

See appendix for summary statistics.
Well 06S001 (Muscogee County, Georgia)

Well 12L021 (Dougherty County, Georgia)

Well 28X001 (Burke County, Georgia)

Cretaceous Aquifer

Monthly mean water level below and above (–) land surface, in feet

Monitoring began 1978

Monitoring began 1980

Blank

where

data are

missing

Trend

1953195519601965197019751980198519901995200020052009

–10

0

 10

 20

 30

 40

 50

 100

 110

 120

 130

 140

 150

 160

 45

 50

 55

 60

 65

 70

 75

 80

42 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Cretaceous Aquifer System

Water levels in 12 wells in the Cretaceous aquifer system 

were used to define groundwater conditions throughout 

central and southwestern Georgia during 2008–2009 (map 

and table, facing page). In this area, water in the Cretaceous 

aquifer system mostly is confined but can be unconfined 

in stream valleys. Hydrographs for selected wells (below) 

illustrate monthly mean water levels for the period of record. 

The hydrographs show periodic upward or downward trends 

that largely reflect changes in pumping. Water levels in 

wells 06S001 and 28X001 both show a long term downward 

trend related to groundwater pumping. The hydrograph for 

well 12L021 shows a sharp water level rise in 2003 when 

pumping was discontinued from a nearby public-supply well.

During the period of record, water levels in 11 of the 

12 wells declined from 0.12 to 0.89 foot per year (ft/yr). 

The only well showing a water level rise (0.04 ft/yr) during 

the period of record was well 12L021 at Albany because of 

decreased pumping for public supply.

During 2008–2009, water levels in seven of the wells 

declined at rates of 0.16 to 3.40 ft/yr and rose in five wells 

at rates of 0.28 to 8.74 ft/yr. The variation in water-level 

response during 2008–2009 probably is related to changes in 

pumping across the area.
Fall

Line

0 25 50 MILES

0 25 50 KILOMETERS

Base modified from U.S. Geological Survey 

1:100,000-scale digital data

N

Jefferson

Washington

Muscogee

Chattahochee

Marion

Schley

Macon

Dooly Pulaski Dodge

Wilcox

Crisp

Sumter Webster

Stewart

Quitman

Randolph

Terrell Lee

Worth

Turner

Ben Hill

Tift

Mitchell Colquitt

Baker

Dougherty

Calhoun Clay

Early

Miller

Irwin

Wheeler Toombs

Tattnall

Evans

Telfair

Montgomery

Crawford

Taylor

Bibb

Twiggs

Wilkinson

Johnson

Emanuel

Bleckley Laurens Treutlen

Houston

Peach

Jenkins

Screven

Effingham

Candler Bulloch

Burke

Glascock

Richmond

23X027

21U004

18U001

12L021

06S001

30AA04

29AA09

28X001

32Y030

18T001

24V001

29AA09

30AA04

32Y031

EXPLANATION

Cretaceous aquifer system

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

Downward trend—Water level 

decline > 0.01 foot per year

GEORGIA

Groundwater Conditions 43

Site name Water-bearing

unit1 County Year monitoringbegan

Water-level trend, in feet, per year2

Period of record From 2008 to 2009

28X001 M Burke 1980 –0.68 –1.87

32Y030 LM Burke 1995 –0.44 0.28

32Y031 LD Burke 1995 –0.51 –0.16

12L021 P Dougherty 1978 0.04 1.57

24V001 M Johnson 1980 –0.60 0.31

21U004 M Laurens 1982 –0.32 –0.23

06S001 T Muscogee 1953 –0.82 –3.40

18T001 M Pulaski 1981 –0.23 –0.70

29AA09 UM Richmond 1990 –0.23 0.51

30AA04 DM Richmond 1979 –0.33 –0.19

18U001 D Twiggs 1975 –0.12 –0.36

23X027 DM Washington 1985 –0.89 8.74

1

M, Midville aquifer system; LM, lower Midville aquifer; LD, lower Dublin aquifer; T, Tuscaloosa Formation; P, Providence 

aquifer; UM, upper Midville aquifer; DM, Dublin–Midville aquifer system; D, Dublin aquifer system. 

2

See appendix for summary statistics.
Well 03PP01 (Walker County, Georgia)

Well 07KK64 (Gordon County, Georgia)

Paleozoic-Rock Aquifers

Monthly mean water level below land surface, in feet

Monitoring began 1997

Blank

where

data are

missing

Trend

197719801985

1990

1995

2000

2005

2009

 8

 10

 12

 14

 16

 18

 20

 22

 12

 14

 16

 18

 20

 22

 24

 26

 28

 30

44 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Paleozoic-Rock Aquifers

Water levels were measured in two wells in the Paleozoicrock aquifers of northwestern Georgia during 2008–2009 

(map and table, facing page). In this area, the Paleozoic-rock 

aquifers are unconfined and show a pronounced response 

to precipitation. Hydrographs for selected wells (below) 

illustrate monthly mean water levels for the period of record. 

The hydrographs show periodic upward or downward trends 

that reflect changes in precipitation and pumping. Overall 

trends during the period of record and during 2008–2009 are 

described below.

During the period of record, the water level in 

well 07KK64 declined 0.19 foot per year (ft/yr) due to pumping 

from a nearby public-supply well. Conversely, the water 

level in well 03PP01 rose 0.04 ft/yr during the period of 

record. During 2008–2009, the water level in well 07KK64 

rose 3.80 ft/yr and declined 0.12 ft/yr in well 03PP01. 

These differences relate to variations in local pumping and 

climatic conditions.
Base modified from 

U.S. Geological Survey 

0 10 20 MILES 1:100,000-scale digital

0 10 20 KILOMETERS

03PP01

07KK64

03PP01

07KK64

EXPLANATION

Paleozoic-rock aquifers

N

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

Downward trend—Water level 

decline > 0.01 foot per year

GEORGIA

Dade

Walker

Catoosa

Whitfield

Murray

Fannin

Gilmer

Pickens

Gordon

Chattooga

Floyd Bartow Cherokee

Cobb

Paulding

Polk

Haralson

Groundwater Conditions 45

Site name County Year monitoring

began

Water-level trend, in feet, per year1

Period of record From 2008 to 2009

07KK64 Gordon 1997 –0.19 3.80

03PP01 Walker 1977 0.04 –0.12

1

See appendix for summary statistics.
Well 21BB04 (Greene County, Georgia)

Well 10DD02 (Fulton County, Georgia)

Monthly mean water level below and above (–) land surface, in feet

–2

0

 2

 4

 6

 8

 10

 12

 0

 2

 4

 6

 8

 10

Monitoring began 1973

Monitoring began 1987

 12

 22

 24

 26

 28

 30

 32

Well 12JJ04 (Dawson County, Georgia)

Blank

where

data are

missing

Trend

1956

1960

19651970197519801985

1990199520002005

2009

crystalline-rock aquifers

46 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Levels 

Crystalline-Rock Aquifers

Water levels in seven wells were measured in crystallinerock aquifers in the Piedmont and Blue Ridge Physiographic 

Provinces of Georgia during 2008–2009 (map and table, 

facing page). In this area, water is present in discontinuous 

joints and fractures and may be confined or unconfined. 

In general, crystalline-rock aquifers have local extent and 

can be greatly affected by localized water use and climate. 

Hydrographs for selected wells (below) illustrate monthly 

mean water levels for the period of record. The hydrographs 

show periodic upward or downward trends that reflect 

changes in precipitation and pumping.

During the period of record, water levels in all seven 

of the wells declined from 0.04 to 0.53 foot per year (ft/yr).

During 2008–2009, water levels in six of the wells rose 

at rates of change ranging from 0.44 to 1.74 ft/yr, which 

corresponds to the end of a 2-year drought in 2008. Water 

levels in one well (13FF30) declined at a rate of 0.22 ft/yr.
0 25 50 MILES

0 20 50 KILOMETERS

Base modified from U.S. Geological Survey 

1:100,000-scale digital data

Fall

Line

Dade

Walker

Catoosa Whitfield

Murray

Fannin

Gilmer

Union Towns

Rabun

Stephens Habersham

White

Dawson

Lumpkin

Pickens Gordon Chattooga

Floyd Bartow Cherokee Forsyth Hall

Banks Franklin Hart

Madison Elbert Jackson

Barrow Gwinnett

DeKalb Fulton

Cobb

Paulding

Polk

Haralson

Carroll

Douglas

Fayette

Clayton

Coweta

Heard

Henry

Rockdale

Newton

Walton

Morgan

Oconee

Clarke Oglethorpe

Wilkes Lincoln

Columbia

Jones Baldwin

Monroe Lamar Pike Meriwether

Troup

Harris Talbot

Upson

McDuffie

Warren

Hancock Jasper Putnam Butts Spalding

Taliaferro Greene

13FF30

10DD02

12JJ04

13FF30

12JJ04

16MM03

14GG02

21BB04

11FF04

EXPLANATION

Crystalline-rock aquifers

N

Observation well, site name, and

 2008–2009 water-level trend

Upward trend—Water level 

rise > 0.01 foot per year

Downward trend—Water level 

decline > 0.01 foot per year

PIEDMONT

BLUE RIDGE

GEORGIA

Groundwater Conditions 47

Site name County Year monitoring

began

Water-level trend, in feet, per year1

Period of record From 2008 to 2009

12JJ04 Dawson 1956 –0.04 1.74

11FF04 DeKalb 1980 –0.05 0.44

10DD02 Fulton 1973 –0.14 1.07

21BB04 Greene 1987 –0.20 1.39

13FF30 Gwinnett 2003 –0.50 –0.22

14GG02 Gwinnett 2003 –0.53 0.73

16MM03 White 1988 –0.04 0.48

1

See appendix for summary statistics.

Dade

Walker

Catoosa Whitfield

Murray

Fannin

Gilmer

Union

Towns

Rabun

Stephens Habersham

White

Lumpkin

Dawson

Pickens

Gordon Chattooga

Floyd Bartow Cherokee Forsyth

Hall Banks Franklin Hart

Jackson Madison Elbert

Barrow

Gwinnett

DeKalb Fulton

Cobb

Paulding

Polk

Haralson

Carroll

Douglas

Clayton

Fayette

Coweta

Heard

Henry

Rockdale

Newton

Walton

Morgan

Oconee

Clarke Oglethorpe

Wilkes Lincoln

Columbia

Richmond

Jefferson

Washington

Baldwin Monroe Jones

Pike Lamar Meriwether

Troup

Harris

Muscogee

Chattahoochee

Marion

Schley

Macon

Dooly Pulaski Dodge

Wilcox

Crisp

Webster

Sumter

Stewart

Quitman

Randolph

Terrell Lee

Worth

Turner Ben Hill

Coffee Bacon

Glynn

Brantley

Pierce

Ware

Berrien Atkinson

Cook

Tift

Mitchell Colquitt

Baker

Calhoun Dougherty

Clay

Early

Miller

Seminole

Decatur Grady Thomas Brooks Lowndes

Lanier

Echols

Clinch Charlton Camden

Irwin

Wheeler

Toombs

Tattnall

Evans

Bryan

Long

Wayne

Appling Jeff Davis

Telfair

Liberty

McIntosh

Chatham

Montgomery

Talbot

Upson

Crawford

Taylor

Bibb

Twiggs

Wilkinson Johnson

Emanuel

Treutlen Laurens Bleckley

Peach

Jenkins

Screven

Effingham

Bulloch Candler

Burke

McDuffie

Warren

Hancock Jasper Putnam Butts Spalding

Greene

Atlantic Ocean

Approximate northern limit 

Upper and Lower 

Floridan aquifers

Houston

Glascock

Savannah

Brunswick

Albany

Groundwater Quality in the Upper and Lower Floridan Aquifers

The quality of water from the Upper and Lower Floridan aquifers is monitored in the 

Albany and coastal areas. In the south-central part of Dougherty County near Albany, wells 

are monitored annually for nitrate as nitrogen concentrations. In coastal Georgia, chloride 

concentration in water from the Upper and Lower Floridan aquifers has been monitored in 

the Savannah and Brunswick areas since the 1950s and in the Camden County area since 

the early 1990s.
Nitrate plus nitrite as N concentration,

 in milligrams per liter

Sampling month and year

U.S. Environmental Protection Agency maximum contaminant level

12L376

2352560

Upper Floridan aquifer well

EXPLANATION

Surficial aquifer well

Flint River streamgage

12K101

12K180

12L061

12L277

12L348

12L373

12L357

12L350

0 

2 

4 

6 

8 

10 

12 

14 

Sept-98 Apr-99 Apr-01 Nov-01 Nov-02 May-03 Nov-03 Nov-04 Nov-05 May-06 Nov-06 Oct-07 Nov-08 Nov-09 

50 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Quality in the Upper

and Lower Floridan Aquifers

City of Albany Area

The Upper Floridan aquifer is shallow in southwestern 

Georgia where agricultural land use is prevalent, which 

increases the susceptibility of groundwater to contamination 

from nitrates and other chemicals. Nitrate as nitrogen (N) 

levels greater than 10 milligrams per liter (mg/L), the 

maximum contaminant level (MCL) for nitrate as N set by 

the U.S. Environmental Protection Agency (2000), have been 

measured in wells southwest of Albany. 

Nitrate plus nitrite as N concentrations have been 

measured in the southwestern Albany area at least annually 

since September 1998. Because nitrite typically represents a 

small fraction of the total concentration, the reported values 

are presented and discussed as nitrate. During November 2008 

and November 2009, samples were collected from selected 

wells and at one site on the Flint River and analyzed for major 

cations and anions and selected nutrients. The graph below 

shows the nitrate trend in selected wells and the Flint River.

Of the 25 wells sampled in November 2008, 14 are 

located in the well-field area where samples have been 

collected annually for the past 10 years. A sample from 

well 12L061, completed in the Upper Floridan aquifer, 

had a nitrate concentration of 12.5 mg/L, greater than the 

10-mg/L MCL. Water from well 12L376, completed in the 

surficial aquifer, had a nitrate concentration of 10.1 mg/L. 

Samples were collected from 13 wells and the Flint 

River during November 2009. Nitrate levels increased at 

most of the wells from November 2008 to November 2009, 

which is a typical response during wet years. Nitrate levels 

dropped slightly at well 12L348 during this period, with a 

larger decrease at well 12L350. 

To assess nitrate concentrations in an area believed 

to provide recharge to the Upper Floridan aquifer, samples 

were collected from eight additional wells in 2008 northwest 

of the well field (A, facing page). The recharge area was 

delineated by preliminary simulations from a groundwaterflow model of the Upper Floridan aquifer (Gordon, 2009). 

Nitrate concentrations in all eight wells were below 2 mg/L 

(Gordon, 2009), similar to concentrations measured in five of 

the wells in July 1993 (Stewart and others, 1999). 

Samples collected during November 2008 and 

November 2009 were plotted on trilinear diagrams (B, facing 

page), which show that the groundwater samples are chemically 

distinct from the surface-water sample. The groundwater 

samples had lower sodium, potassium, and magnesium content 

and higher carbonate and bicarbonate content than the surfacewater sample.

A hazardous-waste site, the T.H. Agriculture & 

Nutrition (THAN) Company Superfund Site (http://www.

clu-in.org/products/costperf/THRMDESP/Thagr.htm, 

accessed January 31, 2011), is located in the northern part 

of Albany (A, facing page). The USGS collected and analyzed 

water samples for pesticides from two wells closest to the 

Superfund Site in November 2008 (wells 12L010 and 12L018). 

The sample from well 12L010 contained no detectable 

pesticides, and the sample from well 12L018 had a very low 

concentration of p,p’-methoxychlor (0.0014 microgram per 

liter (μg/L)), which is below the reporting limit and nearly 

2 orders of magnitude below the MCL of 0.04 mg/L (U.S. 

Environmental Protection Agency, 2000). Although such a low

concentration is not a cause for concern, continued monitoring 

could enable tracking of any increasing trend. Well 12L018 

was sampled again in November 2009, and pesticides were not 

detected in that water sample.

References

Gordon, D.W., 2009, Groundwater conditions and studies in the 

Albany area of Dougherty County, Georgia, 2008: U.S. Geological 

Survey Open-File Report 2009–1244, 54 p.; available online at 

http://pubs.usgs.gov/of/2009/1244/. 

Stewart, L.M., Warner, Debbie, and Dawson, B.J., 1999, Hydrogeology, 

water quality, and potential contamination of the Upper Floridan 

aquifer, western Albany area, Georgia: U.S. Geological Survey WaterResources Investigations Report 99–4140, 42 p.; available online at 

http://pubs.usgs.gov/wri/wri99-4140/. 

U.S. Environmental Protection Agency, 2000, Maximum contaminant 

levels (Part 143, National Secondary Drinking Water Regulations): 

U.S. Code of Federal Regulations, Title 40, Parts 100–149, rev. 

as of July 1, 2000, p. 612–614.

.
62

County Line Rd

Old 

Vanderbilt Dr

Hard Up Rd

River Rd

91

91

234

19

82

Pretoria Rd

11L120

11L077

11L116

11L115

11L092

11L003

11L112

11L111

12L311 12L345 

4.7 12L344

12L357

12L061 12.9

12L376 13.2

12L346 7.1

12L277 9.4

12L350 2.0

12L348

7.8

12K101

3.1

12K175

5.6

12K129

3.3

12L340

5.3

12L373

8.7

12K180

2.3

12L018

12L010

Dougherty

County

Map area

GEORGIA

Albany

No data

< 4

4 to 6

6 to 10

> 10

2008 and 2009

2008 only

Well tested for pesticide 

02352560

0.45 

EXPLANATION

Surface-water site and 

 nitrate plus nitrite as N 

 concentration, in mg/L, 

 November 2009

Well and nitrate plus nitrite

 as N concentration, in 

 milligrams per liter (mg/L)

November 2009

November 2008

 < 2

Base modified from U.S. Geological Survey

1:24,000-scale digital data

0 1 2 3 MILES

0 1 2 3 KILOMETERS

84°20' 84°15' 84°10'

31°35'

31°30'

Albany

Dougherty

County

Dougherty County

Terrell County Lee County

Baker County

A

T H Agriculture & 

Nutrition Company

Flint

Cooleewahee Creek

Kiokee Creek

River

Well field

Well-field area

02352560

0.45 

EXPLANATION

Water sample

Upper Floridan aquifer

Flint River

Percent

Calcium

Magnesium

Sulfate plus chloride

Sodium plus potassium

Chloride, fluoride, nitrate plus 

nitrite as nitrogen

Chloride, fluoride, nitrate plus 

nitrite as nitrogen

Carbonate plus bicarbonate

Sulfate

Calcium plus magnesium

Percent

Percent

 100 

 80 

 60 

 40 

 20 

 0 0 

 20 

 40 

 60 

 80 

 100 0 

 20 

 40 

 60 

 80 

 100 

 0 

 20 

 40 

 60 

 80 

 100 

 100 

 80 

 60 

 40 

 20 

 0 100 

 80 

 60 

 40 

 20 

 0 

 0 

 20 

 40 

 60 

 80 

 100 

 0 

 20 

 40 

 60 

 80 

 100 100 

 80 

 60 

 40 

 20 

 0 

 100 

 80 

 60 

 40 

 20 

 0 

Percent

Calcium

Magnesium

Sulfate plus chloride

Sodium plus potassium

Carbonate plus bicarbonate

Sulfate

Calcium plus magnesium

Percent

Percent

 100 

 80 

 60 

 40 

 20 

 0 0 

 20 

 40 

 60 

 80 

 100 0 

 20 

 40 

 60 

 80 

 100 

 0 

 20 

 40 

 60 

 80 

 100 

 100 

 80 

 60 

 40 

 20 

 0 100 

 80 

 60 

 40 

 20 

 0 

 0 

 20 

 40 

 60 

 80 

 100 

 0 

 20 

 40 

 60 

 80 

 100 100 

 80 

 60 

 40 

 20 

 0 

 100 

 80 

 60 

 40 

 20 

 0 

B November 2008 November 2009

(A) Map of southwestern Albany area showing nitrate plus nitrite as nitrogen (N) concentrations in the well-field 

area, November 2009; and northeast of the well-field area, November 2008; and (B) piper plots of major cation and 

anion compositions of water samples from the Upper Floridan aquifer and the Flint River, November 2008 and 

November 2009.

Groundwater Conditions 51
Base from U.S. Geological Survey

1:100,000-scale digital data

Savannah

Fort Pulaski

National

Monument

Chatham County

Ossabaw

Island

Skidaway

Island

Tybee Is

GEORGIA

37P113

37P114

39Q024

38Q002

37P114 Well and site name

Chloride-monitoring network, 

 Upper and Lower Floridan 

 aquifers, Savannah area

EXPLANATION

0 5 10 MILES

0 5 10 KILOMETERS

N

Chatham

County

52 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Quality in the Upper 

and Lower Floridan Aquifers

City of Savannah Area

During December 2008 and December 2009, borehole 

geophysical logs and discrete water samples were collected 

from open intervals in wells completed in the Upper and 

Lower Floridan aquifers to assess changes in chloride 

concentration in the Savannah area, continuation of a program 

that began in 2003. Borehole geophysical logs include fluid 

resistivity—an indicator of dissolved-solids concentration—

and fluid temperature—an indicator of possible breaches 

in the well casing that might compromise the reliability of 

water-quality measurements. Water samples were collected at 

specific depth intervals in each well to reflect the range of fluid 

resistivity observed in the well during logging. The chloride 

concentrations in water samples are summarized in a table and 

shown graphically on the facing page.

At Fort Pulaski, fluid resistivity logs and water 

samples were collected from well 38Q002 completed in the 

Upper Floridan aquifer (facing page). The fluid resistivity 

logs collected during 2008–2009 indicated no changes or 

breaches in the well casing. During 2008 and 2009, chloride 

concentrations in all samples collected at depths of 200 and 

320 feet (ft) were at or below 12 milligrams per liter (mg/L). 

At Skidaway Island, fluid-resistivity logs and water 

samples were collected from well 37P114 completed in the 

Upper Floridan aquifer and from well 37P113 completed 

in the Lower Floridan aquifer. Water in the Upper Floridan 

aquifer is fresh (chloride concentrations less than 7 mg/L) 

at the Skidaway Island site and chloride concentrations of 

samples from well 37P114 did not appreciably change during 

2008–2009. The fluid-resistivity logs collected indicated no 

changes or breaches in the well casing. During 2008 and 2009, 

chloride concentrations in samples collected at depths of 

300 and 360 ft were less than 10 mg/L. In well 37P113, the 

fluid-resistivity logs collected during 2008–2009 indicated 

no changes or breaches in the well casing. The chloride 

concentrations were higher in samples collected at a depth 

of 1,070 ft and had greater variability than in the samples 

collected from the 900-ft interval. Chloride concentrations 

varied from 4,740 mg/L in 2007 to 1,090 in 2008 and 

3,800 mg/L in 2009. Concentrations in samples collected 

from a depth of 900 ft during the same period ranged from 

950 to 1,590 mg/L. 

At Tybee Island, fluid-resistivity logs and water samples 

were collected from well 39Q024 completed in the Lower 

Floridan aquifer. The fluid-resistivity logs collected during 

2008–2009 indicated no changes or breaches in the well casing. 

Chloride concentrations in samples collected at two depths in 

well 39Q024 increased during 2008–2009, a continuation of an 

upward trend that began in 2007 (Peck and others, 2009; facing 

page). Concentrations in samples from the 845-ft interval rose 

from 2,960 to 3,200 mg/L. Similarly, concentrations in samples 

from the 860-ft interval rose from 2,700 to 3,200 mg/L. 

Reference

Peck, M.F., Painter, J.A., and Leeth, D.C., 2009, Ground-water 

conditions and studies in Georgia, 2006–07: U.S. Geological 

Survey Scientific Investigations Report 2009–5070, 86 p. 

available online at http://pubs.usgs.gov/sir/2009/5070/.
2003 2004 2005 2006 2007 2008 2009

2003 2004 2005 2006 2007 2008 2009

2003200220012000 2004 2005 2006 2007 2008 2009

2003200220012000 2004 2005 2006 2007 2008 2009

Upper Floridan aquifer, Fort Pulaski, well 38Q002

Lower Floridan aquifer, Skidaway Island, well 37P113

Upper Floridan aquifer, Skidaway Island, well 37P114

Lower Floridan aquifer, Tybee Island, well 39Q024

Chloride concentration, in milligrams per liter

1,000

0

2,000

3,000

4,000

5,000

4

6

8

10

12

14

4

6

8

10

12

14

3,500

3,400

3,300

3,200

3,100

3,000

2,900

2,800

2,700

2,600

2,500

845

feet

860

feet

300 feet

360 feet

900 feet

1,070 feet

200 feet

320 feet

Groundwater Conditions 53

Chloride concentration in groundwater from wells in the Upper and Lower Floridan aquifers in the Savannah area, Georgia, 2000–2009.

Site name Other identifier 

Open interval 

(feet below 

land surface)

Waterbearing 

unit1

Water sample 

depth 

(feet below 

land surface)

Chloride 

concentration 

(milligrams 

per liter)

Water sample

depth 

(feet below 

land surface)

Chloride

concentration

(milligrams 

per liter)

December 2008 December 2009

38Q002 U.S. National Park Service, 

Fort Pulaski Pilot House

110 –348 U 200 11.2 200 12.0

320 9.3 320 9.5

37P113 Skidaway Institute test well 1 700–1,100 L 900 727 900 950

1,070 1,090 1,070 3,800

37P114 Skidaway Institute test well 2 262–400 U 300 6.5 300 5.0

360 5.3 360 4.7

39Q024 Georgia Geologic Survey, 

Tybee Island, test well 1

840–880 L 845 2,960 845 3,200

860 2,900 860 3,200

1L, Lower Floridan aquifer; U, Upper Floridan aquifer.
Well 34H391

Interval tapped, 1,070–1,158 feet

Brackish water-zone

Well 33H127

Interval tapped, 823–952 feet

Lower water-bearing zone

Well 33H133

Interval tapped, 520–790 feet

Upper water-bearing zone

500 

1,000 

1,500 

2,000 

2,500 

3,000 

3,500 

4,000 

500 

1,000 

1,500 

2,000 

2,500 

3,000 

3,500 

4,000 

1965197019751980198519901995

2000

20052009

1960

1965

1970

19751980

1985

1990

1995200020052009

Upper Floridan aquifer

Lower Floridan aquifer

0

500

1,000

1,500

2,000

2,500

0

500

1,000

1,500

2,000

2,500

Chloride concentration, in milligrams per liter

Well 34H393

Interval tapped, 615–723 feet

Upper water-bearing zone

Southern Brunswick area Northern Brunswick area

Upper Floridan aquifer

Upper Floridan aquifer

Well 34H403, Interval tapped, 788–982 feet

Lower water-bearing zone

54 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Quality in the Upper 

and Lower Floridan Aquifers

City of Brunswick Area

Chloride concentrations have been monitored in the 

Brunswick area since the late 1950s when saltwater was first 

detected in wells completed in the Upper Floridan aquifer at 

the southern part of the area (Wait, 1965). By the 1960s, 

a plume of saltwater had migrated northward toward two 

major industrial pumping centers. 

Since 1965, chloride concentrations have increased 

markedly in wells completed in the Upper Floridan aquifer 

in the northern Brunswick area. During 2008 and 2009, the 

chloride concentration was above the 250-milligrams per liter 

(mg/L) State and Federal secondary drinking-water standards 

(Georgia Environmental Protection Division, 1997; U.S. 

Environmental Protection Agency, 2000) in a 2-square-mile 

area and exceeded 2,250 mg/L in part of the area.

Graphs of chloride concentrations in water samples 

from wells in the upper and lower water-bearing zones of 

the Upper Floridan aquifer are shown below for wells in 

the southern Brunswick area (wells 34H393 and 34H403) 

and northern Brunswick area (wells 33H127 and 33H133). 

Chloride concentration in water from the Lower Floridan 

aquifer is shown for well 34H391 (graph below) in the 

southern Brunswick area. More information on monitoring 

groundwater quality in the Brunswick area is available at 

http://ga.water.usgs.gov/projects/brunswick/.

Dissolved chloride concentrations in the upper waterbearing zone of the Upper Floridan aquifer at Brunswick 

were mapped for July 2008 using data from 29 wells and for 

July–August 2009 using data from 28 wells (facing page). 

The 2008 and 2009 maps are similar to previously published 

maps for 2006 and 2007 (Peck and others, 2009) and show 

that areas of highest chloride concentrations are near the 

two industrial pumping centers in the northern part of the 

city, and the original area of contamination in the southern 

part of the city.

During 2008–2009, chloride concentrations within the 

plume area decreased in 18 of 28 wells sampled. The greatest 

decrease in concentration was 160 mg/L at well 33H130 in 

the northern part of the plume. Chloride concentrations in 

10 wells increased from 0.1 to 80 mg/L during 2008–2009; 

the largest increase occurred in well 33H133 in the northern 

part of the plume. These changes probably reflect shifts in 

local pumping patterns.

References 

Cherry, G.S., Peck, M.F., Painter, J.A., and Stayton, W.L., 2010, 

Groundwater conditions and studies in the Brunswick–

Glynn County area, Georgia, 2008: U.S. Geological Survey 

Open-File Report 2009–1275, 54 p.; available online at 

http://pubs.usgs.gov/of/2009/1275/.

Georgia Environmental Protection Division, 1997, Secondary 

maximum contaminant levels for drinking water: Environmental 

Rule 391-3-5-19, revised October 1997: Official Code of 

Georgia Annotated Statutes, Statute 12-5-170 (Georgia Safe 

Drinking Water Act), variously paginated.

Peck, M.F., Painter, J.A., and Leeth, D.C., 2009, Ground-water 

conditions and studies in Georgia, 2006–2007: U.S. Geological 

Survey Scientific Investigations Report 2009–5070, 86 p.; 

available online at http://pubs.usgs.gov/sir/2009/5070/.

U.S. Environmental Protection Agency, 2000, Maximum 

contaminant levels (Part 143, National Secondary Drinking 

Water Regulations): U.S. Code of Federal Regulations, 

Title 40, Parts 100–149, rev. July 1, 2000, p. 612–614.

Wait, R.L., 1965, Geology and occurrence of fresh and brackish 

ground water in Glynn County, Georgia: U.S. Geological 

Survey Water-Supply Paper 1613-E , 94 p.
Andrews

Island

East River

Oglethorpe Bay

TURTLE

RIVER

BRUNSWICK

Andrews

Island

East River

Oglethorpe Bay

TURTLE

RIVER

BRUNSWICK

Chloride concentration, July 2008 Chloride concentration, July–August 2009

Newcastle

Street

Street

Norwich

Stonewall Street

Andrews

Island

4th Street

East River

Oglethorpe Bay

TURTLE

RIVER

BRUNSWICK

Change in chloride concentration from 2008 to 2009

N

Base modified from U.S. Geological Survey

1:24,000-scale digital data

Brunswick West, Brunswick East

N

0 0.5

0 0.5

1 MILE

1 KILOMETER

Base modified from U.S. Geological Survey

1:24,000-scale digital data

Brunswick West, Brunswick East

0 0.5

0 0.5

1 MILE

1 KILOMETER

250

750

1,250

1,750

2,250

2,620

 EXPLANATION

MAPS BELOW MAP AT RIGHT

Data point

34H391

–160 to –50

Decrease Increase

–50 to 0

0 to 50

50 to 80

Chloride concentration in 

water from upper 

water-bearing zone of 

Upper Floridan aquifer—

In milligrams per liter

Well and site name— 

L, lower water-bearing zone 

of Upper Floridan aquifer; 

LFA, Lower Floridan aquifer

Change in chloride concentration in 

water from upper water-bearing 

zone of Upper Floridan aquifer 

from 2008 to 2009, in milligrams 

per liter

Area of 

enlarged

map

GEORGIA

Glynn County

Glynn

County

34H391 (LFA)

34H403

34H393

33H130

33H133

33H127(L)

Groundwater Conditions 55
1,000

1,200

1,400

1,600

1,800

2,000

2,200

Well 34H505

J F M A M J J A S NO D J F M A M J J A S NO D

2008 2009

Specific conductance, in microsiemens per centimeter

400

600

800

1,000

1,200

Well 33H325 

6,800

7,000

7,200

7,400

7,600

7,800

8,000

Well 34H514

Blank

where

data are

missing

GEORGIA

Brunswick

Glynn 

County

at right 

Area of

enlarged map

Glynn County

56 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Quality in the Upper 

and Lower Floridan Aquifer

Real-Time Specific Conductance Monitoring in 

Brunswick Area

Beginning in 2007, a network of wells with real-time, 

satellite-telemetry was established at Brunswick to 

monitor changes in specific conductance in the upper 

and lower water-bearing zones of the Upper Floridan 

aquifer (specific conductance is a surrogate for changes 

in chloride concentration). Three of the wells are located 

immediately outside of the chloride plume, and one is 

located inside the plume area (see map, facing page). Of 

these four wells currently monitored in real time, three are 

monitored for daily specific conductance and hourly water 

levels and one is monitored for specific conductance only. 

Specific conductance is monitored in wells 33H325, 

34H505, and 34H514 by pumping once a day from rigid, 

small-diameter tubing installed at predetermined depths 

(see table, facing page) to the water-bearing zone of interest 

(Walls and others, 2009). In supply well 34H134, specific 

conductance is recorded directly in the well-discharge pipe 

every 15 minutes. Data are transmitted every 1 to 4 hours, 

based on equipment, and can be viewed on the Web at 

http://water.usgs.gov/ga/nwis/current?type=gw/. 

A correlation between specific conductance and chloride 

concentration presented by Cherry and others (2010) for the 

Brunswick area was used to determine the possible range 

of chloride concentration in these wells during 2008–2009 

(see table, facing page). Estimated chloride concentration in 

wells 34H514 and 34H134 were at or below the 250-mg/L 

secondary drinking-water standard (Georgia Environmental 

Protection Division, 1997; U.S. Environmental Protection 

Agency, 2000). The estimated chloride concentration in 

wells 34H505 and 33H325 likely exceeded the secondary 

drinking-water standard.
34H505

Approximate boundary of 2009 chloride plume— 

Chloride concentrations at least 250 milligrams per 

liter in the upper water-bearing zone of the Upper 

Floridan aquifer 

EXPLANATION

Real time specific conductance and water-level 

monitoring well

34H514

34H505

33H325

34H134

Andrews

Island

East River

Oglethorpe Bay

TURTLE

RIVER

BRUNSWICK

0 0.5 1 MILE

0 0.5 1 KILOMETER

N

Base modified from U.S. Geological Survey

1:24,000-scale digital data

Brunswick West, Brunswick East

Groundwater Conditions 57

References

Cherry, G.S., Peck, M.F., Painter, J.A, and Stayton, W.L., 

2010, Groundwater conditions and studies in the 

Brunswick–Glynn County area, Georgia, 2009: U.S. 

Geological Survey Open-File Report 2009–1275, 54 p.; 

available online at http://pubs.usgs.gov/of/2009/1275/.

Georgia Environmental protection Division, 1997, 

Secondary maximum contaminant levels for drinking 

water: Environmental Rule 391-3-5-19, revised October 

1997: Official Code of Georgia Annotated Statutes, 

Statute 12-5-170 (Georgia Safe Drinking Water Act), 

variously paginated.

U.S. Environmental Protection Agency, 2000, Maximum 

contaminant levels (Part 143, National Secondary Drinking 

Water Regulations): U.S. Code of Federal Regulations, 

Title 40, Parts 100-149, rev. July 1, 2000, p. 612–614. 

Walls, C.B., Cressler, A.M., and Stayton, W.L., 2009, Realtime water-level and specific conductance monitoring of 

saltwater contamination in the Upper Floridan aquifer, 

Brunswick, Georgia, in Rasmussen, Todd, Carroll, D.G., 

and Georgakakos, Aris, eds., Proceedings of the 2009 

Georgia Water Resources Conference, held April 27–29, 

2009, at the University of Georgia, Athens, Institute of 

Ecology, The University of Georgia, accessed July 2, 2009, 

at http://www.gwri.gatech.edu/conferences/previous-gwrcconferences/gwrc-2009/.

Location of real-time specific conductance monitoring network and estimated chloride concentration in the upper water-bearing zone 

of the Upper Floridan aquifer in the Brunswick–Glynn County area, Georgia, July and August 2009.

Specific conductance, Upper Floridan aquifer, 2008–2009

[μS/cm, microsiemens per centimeter at 25o Celsius; mg/L, milligram per 

liter; LWBZ, lower water-bearing zone; UWBZ, upper water-bearing zone; 

ULWBZ, upper and lower water-bearing zones; modified from Cherry and 

others, 2010]

Site 

name

Waterbearing

zone

Sampling 

interval 

(feet)

Specific

conductance

(μS/cm)

Estimated 

chloride

concentration 

(mg/L)

34H514 UWBZ 605 401–1,130 15–250

34H134 ULWBZ 518–942 452–583 15–45

33H325 LWBZ 900 6,910–7,950 1,800–2,200

34H505 LWBZ 960 1,110–2,030 250–550
58 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Quality in the Upper 

and Lower Floridan Aquifers

Camden County Area

In the Camden County area, chloride concentrations 

have been monitored periodically in the Upper Floridan 

aquifer from 1959 to 1993 and annually to semiannually from 

1994 to the present. In the Lower Floridan aquifer, chloride 

concentrations have been monitored from 2001 to the present. 

During 2008–2009, the U.S. Geological Survey collected a 

total of 32 water samples from eight wells; six wells were 

completed in the Upper Floridan aquifer, and two wells 

were completed in the Lower Floridan aquifer. These wells 

(table, below) are part of a monitoring network maintained 

for the St. Johns Water Management District in Florida.

During 2008–2009, chloride concentrations in the 

Upper and Lower Floridan aquifers were relatively constant. 

Chloride concentrations in the Upper Floridan aquifer 

ranged from 30.2 to 44.8 milligrams per liter (mg/L), which 

are similar to the 20 to 40 mg/L background level for the 

area (Peck and others, 2005) and below the 250-mg/L 

drinking-water standard (Georgia Environmental Protection 

Division, 1997; U.S. Environmental Protection Agency, 

2000). Chloride concentrations in the Lower Floridan aquifer 

remained below the 250-mg/L drinking-water standard, 

ranging from 27.5 to 30.3 mg/L in well 33D073, completed 

in the upper section of the Lower Floridan aquifer, and from 

93.5 to 102 mg/L in well 33D074, completed in the lower 

section of the Lower Floridan aquifer (table, below).

References

Georgia Environmental Protection Division, 1997, 

Secondary maximum contaminant levels for drinking 

water: Environmental Rule 391-3-5-19, revised 

October 1997: Official Code of Georgia Annotated 

Statutes, Statute 12-5-170 (Georgia Safe Drinking Water 

Act), variously paginated.

Peck, M.F., McFadden, K.W., and Leeth, D.C., 2005, Effects 

of decreased ground-water withdrawal on ground-water 

levels and chloride concentrations in Camden County, 

Georgia, and ground-water levels in Nassau County, Florida, 

from September 2001 to May 2003: U.S. Geological Survey 

Scientific Investigations Report 2004–5295, 31 p.; available 

online at http://pubs.usgs.gov/sir/2004/5295/.

U.S. Environmental Protection Agency, 2000, Maximum 

contaminant levels (Part 143, National Secondary Drinking 

Water Regulations): U.S. Code of Federal Regulations, 

Title 40, Parts 100–149, rev. July 1, 2000, p. 612–614.

Chloride-monitoring network in the Floridan aquifer system, Camden County, Georgia

[UF, Upper Floridan aquifer; LF, Lower Floridan aquifer; —, no data]

Site name Aquifer

Open interval 

(feet below

 land surface)

Chloride concentration (milligrams per liter)

May 2008 September 2008 May 2009 September 2009

32E033 UF 420–600 — 130.2 — 131.4

33D054 UF 563–1,000 1

34.1 130.7 131.4 132.2

33D061 UF 550–1,090 1

44.6 140.3 144.8 141.1

33E049 UF 522–840 — 135.1 136.1 133.7

33E053 UF 570–900 1

37.9 135.0 135.8 136.3

34E001 UF 540–640 1

34.7 132.0 132.5 133.3

33D073 LF 1,360–1,500 30.3 27.5 28.5 29.1

33D074 LF 1,840–2,004 99.4 93.5 98.7 102.0

1

Brian McGurk, St. Johns River Water Management District, written commun., February 2010. 
0 5 10 MILES

0 5 10 KILOMETERS

N

Base from U.S. Geological Survey

1:100,000-scale digital data

Camden County

33E053

33D054

33E049

32E033 34E001

34E001

EXPLANATION

Chloride-monitoring well and site name

33D061

33D073

33D074

St Marys

GEORGIA

Well 33E053

Well 33E049

Well 32E033

26

30

34

42

38

Well 33D061

26

30

34

38

42

26

Well 33D054

30

34

38

42

Upper Floridan aquifer

Well 33D073

24

28

32

36

40

44

48

Lower Floridan aquifer

NOTE: Vertical scales vary

Chloride concentration, in milligrams per liter

Chloride concentration, in milligrams per liter

Well 33D074

60

80

100

120

140

Well 34E001 1984

198619881990

19921994

1996

1998200020022004

200620082009

26

30

34

38

42

1984198619881990

19921994

1996

19982000

20022004

200620082009

26

30

34

38

42

20

40

60

80

100

120

140

160

180

200

Groundwater Conditions 59

Dade

Walker

Catoosa Whitfield

Murray

Fannin

Gilmer

Union

Towns Rabun

Stephens Habersham

Lumpkin White

Dawson

Pickens

Gordon Chattooga

Floyd Bartow Cherokee Forsyth

Hall Banks Franklin Hart

Madison Elbert Jackson

Barrow Gwinnett

DeKalb Fulton

Cobb Paulding

Polk

Haralson

Carroll

Douglas

Clayton

Fayette

Coweta Heard

Henry

Newton

Walton

Morgan

Oconee

Clarke Oglethorpe

Wilkes Lincoln

Columbia

Richmond

Agricutural water-use project

Washington

Baldwin Monroe Jones

Pike Lamar Meriwether

Troup

Harris

Muscogee

Chattahoochee

Marion

Schley

Macon

Dooly Pulaski Dodge

Wilcox

Crisp

Sumter Webster

Stewart

Quitman

Randolph Terrell Lee

Worth

Turner Ben Hill

Coffee Bacon

Brantley

Pierce

Ware Berrien Atkinson

Cook

Tift

Mitchell Colquitt

Baker

Calhoun Dougherty

Clay

Early

Miller

Seminole

Decatur

Grady Thomas Brooks

Lowndes

Lanier

Echols

Clinch Charlton Camden

Irwin

Wheeler

Toombs

Tattnall

Evans Bryan

Long

Wayne

Appling Jeff Davis

Telfair

Liberty

McIntosh

Glynn

Chatham

Montgomery

Talbot

Upson

Crawford

Taylor

Bibb

Twiggs

Wilkinson Johnson

Emanuel

Treutlen Laurens Houston

Bleckley

Peach

Jenkins Screven

Effingham

Bulloch Candler

Burke

Glascock

McDuffie

Warren

Hancock

Taliaferro

Jasper Putnam Butts Spalding

Greene Rockdale

Jefferson

FORT

STEWART

Lawrenceville

Albany

Brunswick

Augusta

Atlantic Ocean

HUNTER ARMY AIRFIELD

Selected Groundwater Studies in Georgia, 2008–2009

The U.S. Geological Survey (USGS), in cooperation with local, State, and other Federal 

agencies, conducted several studies in Georgia and adjacent States during 2008–2009 to 

better define the quantity and quality of groundwater and to monitor hydrologic conditions. 

Summaries of current USGS studies in Georgia are provided in the following sections and 

include information regarding

• Study title 

• Study area location 

• Study chief

• Cooperating agency or agencies

• Year study began

• Problem

• Objectives

• Progress and significant results 
Albany

Dougherty

County

GEORGIA

Flint R

Dougherty County

Albany

Well field

62 Groundwater Conditions and Studies in Georgia, 2008–2009

levels were higher during 2009 than during 2008. The 

well-field pumping did not result in the formation of 

a cone of depression surrounding the well field.

• Continued to map sinkholes at the well field. No new 

sinkholes formed during 2008; however, during 2009, 

six new sinkholes developed, two on January 12, 2009, 

two on April 26, 2009, and two on July 6, 2009.

• Began to study the reasons for sinkhole formation at the 

well field with regard to precipitation and water-level 

changes within the Upper Floridan aquifer.

• Continued development of a groundwater model to simulate 

flow in the vicinity of the Albany well-field area.

Reference

U.S. Environmental Protection Agency, 2000, Maximum 

contaminant levels (Part 143, National Secondary Drinking 

Water Regulations): U.S. Code of Federal Regulations, 

Title 40, Parts 100–149, rev. as of July 1, 2000, p. 612–614.

City of Albany Cooperative Water Program

Study Chief Debbie Warner Gordon

Cooperator Albany Water, Gas, and Light

 Commission

Year Started 1977

Problem

Long-term heavy pumping from the Claiborne and 

Clayton aquifers and the Cretaceous aquifer system (includes 

the Providence aquifer), which underlie the Upper Floridan 

aquifer, has resulted in substantial water-level declines in 

these deep aquifers in the Albany area. To provide additional 

water supply and reduce the demand on the deep aquifers, the 

Albany Water, Gas, and Light Commission (WGL) developed 

a large well field southwest of Albany with wells completed in 

the Upper Floridan aquifer, a karstic unit that is the uppermost 

reliable source of water in the area. Because of local recharge 

to the aquifer, water quality may be affected by land-use 

practices. Concentrations of nitrate plus nitrite as nitrogen 

exceeding the 10-milligrams per liter (mg/L) maximum 

contaminant level (U.S. Environmental Protection Agency, 

2000) have been detected in some wells upgradient from 

the well field.

Objectives 

• Monitor water-level fluctuations in the five aquifers in the 

Albany area and relate water-level trends to changes in 

climatic conditions and pumping patterns. 

• Describe the groundwater flow and water quality of the 

Upper Floridan aquifer near the new well field in the southwestern Albany area. 

Progress and Significant Results, 2008–2009

• Continued operation of the 14-well continuous groundwaterlevel monitoring network in the surficial, Upper Floridan, 

Claiborne, Clayton, and Providence aquifers.

• Continued groundwater-quality monitoring program. 

Water samples were collected and analyzed for major 

cations and anions, and selected nutrients during 

November 2008 (25 wells), and November, 2009 (17 wells). 

The USGS sampled wells 12L010 and 12L018 (map facing 

page), two of WGL’s municipal supply wells, for pesticides 

in November 2008 and well 12L018 for pesticides in 2009. 

• Constructed potentiometric-surface maps for the Upper 

Floridan aquifer near the well field based on measurements 

from 81 wells during November 2008, and 64 wells during 

November 2009. Both maps indicate that water generally 

flows from northwest to southeast near the well field. Water 

Albany Water, Gas, and Light Commission 

well field, Albany, Georgia, April 21, 2009. 

Photo by Debbie Warner Gordon, USGS.
0

0

1,000 FEET

200 METERS

500

100

N

12L384

12L382

12L381

12L380

12L379

12L378

Well field

>10

0 to 10

Above 0 to 10

Below

>10

EXPLANATION

Sinkhole

Production well

Water level, in feet, above or below top of 

Floridan aquifer—Indicated as zero

Not pumping Pumping

Watertreatment

plant

12L277

12L018

12L010

Well field

map detail

above

12K180

84°20' 84°15' 84°10'

31°35'

31°30'

DOUGHERTY COUNTY

TERRELL COUNTY LEE COUNTY

DOUGHERTY 

COUNTY BAKER COUNTY

Albany

County Line Rd

Old Pretoria Rd Vanderbilt Dr

Hard Up Rd

River Rd

82 19

234

62

91

Flint

Cooleewahee Creek

River

Kiokee Creek

Well

EXPLANATION

Base modified from U.S. Geological Survey

1:24,000-scale digital data

0 1 2 3 MILES

0 1 2 3 KILOMETERS

1

0

2

3

4

5

January–

March

April–

June

July–

September

Number of sinkholes per month

Jan 

Apr 

July

Oct

Jan 

Apr 

July

Oct

Daily depth to water level, in feet 

below land surface

 2008 2009

Mean daily statistic (8 years)

Daily mean depth to water level

Period of approved data

EXPLANATION

35

30

25

20

Selected Groundwater Studies in Georgia, 2008–2009 63

Well 12K180 located on Victory Street, Albany, Georgia, 

April 21, 2009, following more than 15 inches of rain during 

March and April 2009. Photo by Debbie Warner Gordon, USGS.

Site map and well locations, Albany area.

Water levels relative to the top of the Upper Floridan aquifer at the Albany well field during January 12, 2009. 

Water levels were below the top of the aquifer in much of the western part of the well field and in the northeast 

corner. Two production wells in the field were pumping during the period when two sinkholes formed.

Water level in well 12L277 (see map on right for location). 

No sinkholes formed in the well field during 2008, but 

six sinkholes formed in the well field during 2009.
Richmond

County

GEORGIA

Augusta

F O R T G O R D O N

Augusta

Hephzibah Blythe

2

3

1 Enlarged map

 on facing page

Monitoring well and identification

Well field and number

EXPLANATION

2

29AA42

29AA04

RICHMOND COUNTY

64 Groundwater Conditions and Studies in Georgia, 2008–2009

General area of the groundwater monitoring study showing the three 

municipal well fields and recorder well in the Augusta–Richmond 

County area of Georgia.

• Collected water samples during June–July 2008 and 

September 2009 and analyzed for VOCs near well field 

number 2. 

• Collected water samples from selected wells in 

September 2009 for analysis of stable isotopes to provide 

an indication of the source(s) of low-level contaminants 

and age of water.

• Conducted borehole geophysical logging and flowmeter 

testing, and collected a grab water sample from 

well 30BB35 upgradient of well field number 2. Results 

indicate that borehole flow is downward from shallow to 

deep zones. VOCs were not detected in two water-quality 

samples collected from the well in September 2009.

Reference 

Williams, L.J., 2007, Hydrogeology and potentiometric surface 

of the Dublin and Midville aquifer systems in Richmond 

County, Georgia, January 2007: U.S. Geological Survey 

Scientific Investigations Map 2982, 1 sheet; available online 

at http://pubs.usgs.gov/sim/2007/2982/.

Groundwater Monitoring Program for the 

Augusta–Richmond County Area

Study Chief John S. Clarke

Cooperator Augusta Utilities Department

Year Started 2006

Problem

Water supply in the Augusta–Richmond County area is 

provided in part by three well fields that withdraw water from 

the Dublin–Midville aquifer system—a Late Cretaceous sand 

aquifer. Low levels of the volatile organic compounds (VOCs) 

tetrachloroethene and trichloroethene have been detected in a 

supply well at the northernmost extent of well field number 2. 

To ensure that groundwater pumping does not adversely affect 

water levels in adjacent areas and to monitor groundwater 

quality, the U.S. Geological Survey operates a groundwater 

monitoring program for the Augusta–Richmond County area. 

Data from this network provide information to support watermanagement decisions and serve as a basis for future groundwater-modeling efforts while adding to improved regional 

characterization of groundwater conditions. 

Objectives

• Determine current groundwater levels, flow directions, 

and water quality of the Dublin–Midville aquifer system 

in the Augusta–Richmond County area. 

• Monitor groundwater fluctuations and trends by operating 

a continuous water-level recorder network.

• Monitor groundwater quality in the vicinity of well field 

number 2 and assess the source of low-level volatile 

organic compounds.

Progress and Significant Results, 2008–2009

• Operated continuous water-level recorder network in wells 

30AA06, 30AA33, and 30AA35 near well field number 2.

• Constructed three new test wells at two sites—one two-well 

site upgradient of well field number 2 (wells 30AA37 and 

30AA38), and one single-well site located northwest of 

well field number 3 (well 29AA42).

• Obtained water-level measurements during June 2008 and 

September 2009 and constructed potentiometric-surface 

maps for the Dublin–Midville aquifer system.

• Conducted aquifer test at well field number 2 during 

October 19–24, 2009, to assess hydraulic properties of 

water-bearing units and to evaluate changes in groundwater 

levels and flow directions when various combinations of 

wells are pumped.
Recovery after 

wellfield 

shutdown

Drawdown

from 

pumping

well 

30AA06

Recovery

after 

shutdown

well

Normal wellfield operations 30AA06

See

map A

See

Water level, in feet below 

map B

land surface

October 2009

36

38

40

42

44

46

16 17 18 19 20 21 22 23

Well 30AA37

Well and identification 

150

EXPLANATION

Potentiometric contour—Shows altitude at which water level 

would have stood in tightly cased wells. Dashed where 

approximately located. Hachures indicate depression. 

Contour interval variable. Datum is NGVD of 1929

Direction of groundwater flow

Groundwater divide

30AA37

l

l l

l

l

l l l

l l

l

l

l

l l l

l l

l l l l

81°59'30" 81°59' 81°58'30" 81°58'

33°22'

33°22'30"

33°21'30"

81°59'30" 81°59' 81°58'30" 81°58'

33°22'

33°22'30"

33°21'30"

30AA33

30AA25

30AA37

30AA11

30AA07

30AA06

30AA10

30AA09

30AA18

30BB35

30AA33

30BB35

30AA06

30AA25

30AA37

30AA11

30AA07

30AA10

30AA18 30AA09

115

125

110

130

135

120

120

120

130

135

115

110

125

110

70

115

100

80

90

A. October 21, 2009, 6:00 a.m.

4 H Club Rd

Tobacco Rd

Mike Padgett Hwy

Doug Barnard Pkwy

0 500 METERS

0 0.25 0.5 MILE

250

Base from U.S. Geological Survey

1:2,000,000-scale digital data

B. October 22, 2009, 6:00 a.m.

81°59'30" 81°59' 81°58'30" 81°58'

33°22'

33°22'30"

33°21'30"

30AA25

30AA37

30AA35 30AA36

30AA11

30AA07

30AA06

30AA10

30AA09

30AA08

30AA18

30BB35

30AA08

30AA11

30AA25

30AA27

30AA19

30AA38

Undetectable volatile organic compound levels

Detectable volatile organic compound levels

Detectable levels of chlorine 

 disinfection byproducts

Well and identification with— 

EXPLANATION

0

Base from U.S. Geological Survey

1:2,000,000-scale digital data

500 METERS

0 0.25 0.5 MILE

250

4 H Club Rd

Tobacco Rd

Doug Barnard Pkwy

Mike Padgett Hwy

Selected Groundwater Studies in Georgia, 2008–2009 65

following initiation of pumping in well 30AA06. Note a groundwater 

divide has formed between wells in the southern part of the well 

field (not pumping) and the pumping well 30AA06. Groundwater 

north of this line flows toward well 30AA06, whereas south of the 

line water flows southeastward.

Results of water-quality monitoring near well field number 

two during 2008 and 2009 indicate presence of low-level 

concentrations of volatile organic compounds in some wells. 

Long-term water-quality monitoring provides information on 

water-quality trends to help assess contaminant migration. 

Analysis of groundwater age provides an indication of 

potential source areas of groundwater withdrawn at the 

well field. The apparent year of groundwater recharge 

in shallow well 30AA38, completed at a depth of 120 feet 

was 1991; whereas deeper wells at the well field (depths 

typically greater than 250 feet) were recharged between 

1980 and 1984.

Graph and maps showing water levels in the Midville aquifer system 

near well field number 2 during aquifer test conducted in October 2009. 

Water levels shown on the graph are from well 30AA37, located 

upgradient of the well field. Map A shows water levels about 45 hours 

following shutdown of well field. Map B shows water levels 24 hours 
SOUTH

CAROLINA

GEORGIA

Model area

Glynn

County

Area of

enlarged

map on

facing page

Glynn County

Brunswick COASTAL PLAIN

66 Groundwater Conditions and Studies in Georgia, 2008–2009

City of Brunswick and Glynn County 

Cooperative Water Program

Study Chief Gregory S. Cherry

Cooperator City of Brunswick, Glynn County

 Jekyll Island Authority

Year Started 1959

Problem

In the Brunswick area, saltwater has contaminated the 

Upper Floridan aquifer for more than 50 years. Currently 

within an area of 2 square miles in downtown Brunswick, 

the aquifer yields water with a chloride concentration greater 

than 2,000 milligrams per liter (mg/L), markedly higher than 

the State and Federal secondary drinking-water standard of 

250 mg/L (Georgia Environmental Protection Division, 1997; 

U.S. Environmental Protection Agency, 2000). This chloride 

contamination has constrained further development of the Upper 

Floridan aquifer in the Brunswick area and stimulated interest 

in the development of alternative sources of water, primarily 

from the shallower surficial and Brunswick aquifer systems.

Objectives

• Define and simulate mechanisms of groundwater flow

and the occurrence and movement of saltwater in the 

Floridan aquifer system.

• Assess alternative sources of water supply from the 

surficial and Brunswick aquifer systems and the 

Lower Floridan aquifer.

• Monitor long-term groundwater levels and quality 

including real-time monitoring of the spatial extent of 

chloride contamination in the Upper Floridan aquifer.

• Develop and maintain a comprehensive 

groundwater database.

Progress and Significant Results, 2008–2009

A network of 32 continuous groundwater-level

monitoring wells was operated—12 wells in the Upper Floridan 

aquifer, 8 wells in the Lower Floridan aquifer, 7 wells in the 

Brunswick aquifer system, and 5 wells in the surficial aquifer 

system (C, facing page). Of these 32 wells, 20 are funded by 

the Georgia Environmental Protection Division through the 

Coastal Georgia Sound Science Initiative.

Potentiometric surfaces of the Upper Floridan aquifer 

were mapped as follows:

• July 2008—mapping was based on water-level 

measurements made in 35 wells (Brunswick area only).

• August 2009—mapping was based on water-level 

measurements made in 52 wells (all of Glynn County).

• Chloride concentration of the Upper Floridan aquifer 

was mapped as follows:

• July 2008—mapping was based on analyses of samples 

collected from 67 wells.

• July–August 2009—mapping was based on analyses 

of samples collected from 60 wells.

A regional MODFLOW model of coastal Georgia and 

adjacent parts of Florida and South Carolina (Payne and 

others, 2005) was refined with higher resolution near the area 

of chloride contamination at Brunswick. The revised model 

is being used to assess the effects of pumping on hydraulic 

gradients along the outer margin of the contaminated area.

Real-time monitoring systems were installed in wells 

completed in the upper and lower water-bearing zones of 

the Upper Floridan aquifer that surround the area of chloride 

contamination. The following continuous data were collected:

• Water levels at Southside Baptist Church (wells 34H504 

and 34H505), Perry Park (well 34H514), and Georgia–

Pacific Cellulose (wells 33H324 and 33H325).

• Specific conductance at Southside Baptist Church 

(well 34H505), Perry Park (well 34H514; hydrograph, 

facing page), Georgia–Pacific Cellulose (well 33H325), 

and Brunswick Villa (well 34H134).

Information from the real-time groundwater-monitoring

sites can be accessed at http://waterdata.usgs.gov/ga/nwis/

current/?type=quality&group%20Key=basin%20cd and

http://waterdata.usgs.gov/ga/nwis/current/?type=gw&group_

key=county_cd.

References 

Cherry, G.S., Peck, M.F., Painter, J.A, and Stayton, W.L., 2010, Groundwater conditions and studies in the Brunswick–Glynn County area, 

Georgia, 2008: U.S. Geological Survey Open-File Report 2009–1275, 

54 p.; available online at http://pubs.usgs.gov/of/2009/1275/.

Georgia Environmental Protection Division, 1997, Secondary 

maximum contaminant levels for drinking water: Environmental 

Rule 391-3-5-19, revised October 1997: Official Code of Georgia 

Annotated Statutes, Statute 12-5-170 (Georgia Safe Drinking Water 

Act), variously paginated.

Payne, D.F., Rumman M.A., and Clarke J.S., 2005, Simulation of groundwater flow in coastal Georgia and adjacent parts of South Carolina and 

Floridan Predevelopment, 1980, and 2000: U.S. Geological Survey 

Scientific Investigations Report 2005–5089, 91 p.; available online at 

http://pubs.usgs.gov/sir/2005/5089/.

U.S. Environmental Protection Agency, 2000, Maximum contaminant 

levels (Part 143, National Secondary Drinking Water Regulations): 

U.S. Code of Federal Regulations, Title 40, Parts 100–149, rev. 

July 1, 2000, p. 612–614.
33J065

33J062

34H188

33H133

34H500

34H495

33H206

33H207

33H208

33H324

33H325

35H068

34H515

34H391

34H371

33H127

34H505

34H504

34H537

34H536

34J077

34J044

35H070

35H076

35H077

34H334

34H514

34H492

34H134

34J081

34J080

34J082

34G033

NEWCASTLE STREET

NORWICH STREET

STONEWALL STREET

Andrews

Island

4TH STREET

B r u n swic k

East River

Oglethorpe Bay

TURTLE

RIVER

B. Hydrogeologic units and model layers

C. Groundwater-level monitoring network

A. Hydrogeologic units and model layers

Water-table zone Upper Floridan aquifer

FLORIDAN AQUIFER SYSTEM

Lower Floridan aquifer

Fernandina 

permeable 

zone

Confining unit

Not

modeled

Lower Floridan

confining unit

Upper Floridan confining unit

Hydrogeologic unit

Confining

unit

Upper waterbearing zone

Upper 

Floridan semiconfining unit

Lower waterbearing zone

Revised

model 

Model layer

Aquifer 

system

Savannah Brunswick

1

GHB

(not

modeled)

2

3

4

6

10

11

5

7

8

9

Not

modeled

1

GHB

(not

modeled)

2

3

4

6

7

5

[GHB, general-head boundary]

Upper

Brunswick

 aquifer

Lower

Brunswick

 aquifer

Upper waterbearing zone

Lower waterbearing zone

SURFICIAL

AQUIFER SYSTEM

BRUNSWICK

AQUIFER SYSTEM

Confining

unit

Confining

unit

Payne and 

others, 2005

A digital model is being developed to simulate 

groundwater flow in the vicinity of the chloride 

plume at Brunswick. The model is based on a 

regional model developed by Payne and others 

(2005) as part of the Coastal Sound Science 

Initiative. A greater number of model layers 

(A) and finer grid resolution (B) are being applied 

to enable more detailed simulations in the vicinity 

of the chloride plume, including assessment of 

the effects of pumping on the hydraulic gradients 

near the plume. A groundwater-level monitoring 

network (C) helps assess current hydrologic 

conditions and the effectiveness of watermanagement practices.

EXPLANATION

No pumping

0.01 to 0.99

1.00 to 2.99

3.00 to 4.99

5.00 to 6.79

0

0

0.5

0.5 1 KILOMETER

Base modified from U.S. Geological Survey 1 MILE

1:100,000-scale digital data

Area of

map B

above

Total estimated pumping 

per grid cell— In million 

gallons per day, during 

2004, layers 7 and 9 

(Upper Floridan aquifer)

Approximate 

boundary of 2005 

chloride plume

(Cherry and 

others, 2010)

33J065

0 3 6 MILES

0 3 6 KILOMETERS

Base modified from U.S. Geological Survey

1:100,000-scale digital raster graphics

34J044

N

N

WAYNE

GLYNN

Brunswick

Well in Brunswick–

 Glynn County network

Climatic monitoring site

EXPLANATION

Atlantic Ocean

Georgia Environmental 

 Protection Division 

 monitoring site

Jekyll

Island

St Simons

Island BRANTLEY

CAMDEN

MCINTOSH

82

341

95

17

Selected Groundwater Studies in Georgia, 2008–2009 67
GA

SC

GEORGIA

Model

boundary

BRYAN

BULLOCH

LIBERTY LONG

EVANS

FORT

STEWART

ATLANTIC

OCEAN

HUNTER

ARMY

AIRFIELD

SOUTH

CAROLINA

CHATHAM

Hilton

Head

Island

Savannah

68 Groundwater Conditions and Studies in Georgia, 2008–2009

Progress and Significant Results, 2008–2009

• Completed construction and field testing of new production 

well at HAAF completed in the Lower Floridan aquifer. 

Field testing included collection of drill cuttings, core, 

borehole geophysical logs and flowmeter data, conducting 

aquifer-performance tests in the Upper and Lower Floridan 

aquifers, collection and analysis of water samples from 

a variety of depths, conducting packer slug tests in the 

Lower Floridan confining unit, and laboratory analysis 

of core samples for determination of vertical hydraulic 

conductivity. Data were synthesized into an existing 

groundwater-flow model modified to assess interaquifer 

leakage between the Upper and Lower Floridan aquifers.

• Conducted evaluation of the hydrology, water-quality, 

and water-supply potential of four ponds at HAAF. This 

included determination of the volume of water stored in 

the ponds under a range of stage conditions; measurement 

of streamflow discharging from one of the ponds and 

development of a stage-discharge relation to determine flow 

rates over a range of climatic conditions; estimating net 

groundwater seepage by developing hydrologic budgets; 

and sampling and analysis to determine pond water quality. 

Results of the investigation are documented in a final report 

(Clarke and Painter, 2010).

References

Clarke, J.S., and Painter, J.A., 2010, Hydrology, water quality, 

and water-supply potential of ponds at Hunter Army 

Airfield, Chatham County, Georgia, November 2008–

July 2009: U.S. Geological Survey Scientific Investigations 

Report 2009–5265, 34 p.; available online at http://pubs.

usgs.gov/sir/2009/5265/.

U.S. Environmental Protection Agency, 2009, Drinking water 

contaminants, accessed February 3, 2011, available online 

at http://water.epa.gov/drink/contaminants/index.cfm.

Williams, L.J., 2010, Summary of hydrologic testing of 

the Floridan aquifer system at Hunter Army Airfield, 

Chatham County, Georgia: U.S. Geological Survey 

Open-File Report 2010–1066, 30 p.; available online at 

http://pubs.usgs.gov/of/2010/1066/.

Fort Stewart–Hunter Army Airfield 

Alternative Water Resources 

Study Chief John S. Clarke

Cooperator U.S. Department of the Army

Year Started 2009

Problem

The U.S. Department of the Army Fort Stewart and 

Hunter Army Airfield (HAAF), Georgia, are home of the 

3rd Infantry Division. These two sites are located in coastal 

Georgia near Savannah, where concern over saltwater intrusion 

at Hilton Head Island, South Carolina, has resulted in increased 

restrictions on groundwater withdrawals from the Upper 

Floridan aquifer by the Georgia Environmental Protection 

Division (GaEPD). To meet the growing water demand in 

Georgia’s coastal area, the GaEPD has encouraged use of 

alternative water sources to the Upper Floridan, including 

streams, ponds, and wells completed in the Lower Floridan 

aquifer and shallower surficial and Brunswick aquifer systems.

To assess the water-resource potential of these various 

sources for potable supply and irrigation, the U.S. Geological 

Survey, in cooperation with the Department of the Army, 

is conducting detailed field investigations at HAAF and 

Fort Stewart.

Objectives

• Analysis of shallow alternative aquifers (surficial and 

Brunswick aquifer systems)—Conduct detailed site 

investigations in new and existing wells, including borehole 

geophysical logging and flowmeter testing, depth-integrated 

water sampling and analysis, and aquifer-performance 

testing to determine the drawdown and water-bearing 

capacity of the aquifer.

• Analysis of Lower Floridan aquifer—Conduct detailed 

site investigations, including borehole geophysical logging 

and flowmeter testing, depth-integrated water sampling 

and analysis, and aquifer-performance testing to determine 

the drawdown and water-bearing capacity of the Lower 

Floridan aquifer and interconnection (leakage) with the 

overlying Upper Floridan aquifer. Perform groundwater 

model analyses to further assess the effects of pumping on 

leakage between the Upper and Lower Floridan aquifers.

• Analysis of ponds—Conduct detailed site investigations of 

selected ponds to assess water-supply potential, including 

describing the local site setting and pond bathymetry, 

estimating the volume of water stored in the ponds over a 

range of stages, estimating net groundwater seepage derived 

from water-budget analyses and pond-discharge tests, 

and determining the suitability of pond water quality for 

irrigation purposes.
1,000

1,075

875

700

525

1,000

1,075

875

700

525

Sample depth below land surface, in feet

Microsiemens per

centimeter at 

25 degrees Celsius

Magnesium

Sodium

Specific conductance

Fluoride

Chloride

1 10 1,000 100 1 10 1,000 100

1001 10,000

0 21 3

Less than 1.0

Potassium

105 20 25 15

Milligrams per liter

Milligrams 

per liter

Sulfate

200100 300

1,000

1,075

875

700

525

Alkalinity as CaCO3

0 200100 300

0 0

0

2010 30

Days

Pond volume, in million gallons

1,000

500

250

0 20 40 60 80 100 120 140

0

2

4

6

8

10

12

14

NOT TO SCALE

Groundwater

inflow

Groundwater

outflow

Water table

Rainfall

Pond

evaporation

Earthen 

dam

Conduit

outflow

Dam

leakage

Overflow

Surficial aquifer

Study pond 

Pond stage 

Geophysical logs and flowmeter data collected from a test boring open 

to both the Upper and Lower Floridan aquifers at HAAF were used to 

determine the relative flow contribution from water-bearing zones and 

to delineate the top and bottom of the Upper and Lower Floridan 

aquifers. While pumping at a rate of 847 gallons per minute (gal/min), 

flowmeter data indicated that the Upper Floridan aquifer, as a whole, 

produced 83.5 percent of the total flow with the remaining 16.5 percent 

derived from the underlying confining unit and the Lower Floridan 

aquifer. Two intervals in the Upper Floridan aquifer, 405–435 feet (ft) and 

475–505 ft, produced the highest percentage of accumulated flow with 

an estimated 610 gal/min or 72 percent of the total pumping rate 

(modified from Williams, 2010).

Stormwater inflow

Discrete water samples collected from the Upper and Lower 

Floridan aquifers indicate that constituent concentrations 

generally increase with depth and are within drinking-water 

standards, with the exception of the deepest sample at 1,075 feet 

(ft). Water from the 1,075-ft interval had a chloride concentration 

of 480 milligrams per liter (mg/L), which exceeds the U.S. 

Environmental Protection Agency (USEPA) Secondary Maximum 

Contaminant Level (SMCL) of 250 mg/L (U.S. Environmental 

Protection Agency, 2009). The sulfate concentration of water 

from the same interval (240 mg/L) is slightly below the USEPA 

SMCL of 250 mg/L (U.S. Environmental Protection Agency, 2009). 

Flowmeter testing in the completed Lower Floridan aquifer well 

indicates that water from the 1,075-ft zone contributes less than 

2 percent of the total flow to the well, and therefore the relatively 

higher concentrations of chloride and sulfate do not adversely 

affect the overall water quality from the well.

At one of the ponds at HAAF, the total available volume was 

12.8 million gallons and the average rate of net groundwater 

flow was 19 gallons per minute (gal/min). Assuming long-term 

average climatic conditions for July and an 8-hour-per-day 

pumping period, total depletion of pond volume would occur 

after 29 days at a pumping rate of 1,000 gal/min, after 60 days 

at a pumping rate of 500 gal/min, and after 130 days at a 

pumping rate of 250 gal/min. (modified from Clarke and 

Painter, 2010).

Hydrogeology

Feet

0 500 Land

surface

237 0 2,0001,000 0 100 200

100

200

300

400

500

600

700

800

900

1,000

1,100

Pumping rate—

 In gallons

 per minute

EXPLANATION

Conceptual model of pond-aquifer flow for a typical coastal area pond. 

Water supply from ponds is derived from the amount of available 

storage in the pond replenished by groundwater inflow and surface 

runoff. Evaporation, groundwater outflow, and leakage through earthen 

dams accounts for losses to pond storage. Field data including 

precipitation, evaporation, pond stage, and pond bathymetry were used 

to develop a hydrologic budget for three ponds at Hunter Army Airfield 

(HAAF) and assess their potential as sources of irrigation water supply 

(modified from Clarke and Painter, 2010).

Percent

contribution

Resistivity,

in ohm-meters Borehole flow (gallons per minute)

Upper Floridan aquifer Upper confining unit Lower Floridan aquifer

Surficial 

aquifer

systemConfining unit Confining unit

Bottom of 

16-inch 

casing is at 

333 feet

Same flowmeter 

log plotted at 

different scales

Stationary point 

measurement

Flow is exaggerated 

through this zone 

probably because of 

turbulence resulting 

from variable borehole 

diameter in 

this interval

6.7

44.9

27.2

1.8

3.0

4.3

1.5

5.4

1.8

3.0

0.6

Lateral

16-inch 

normal

64-inch 

normal

Caliper,

in inches

Selected Groundwater Studies in Georgia, 2008–2009 69
GEORGIA

Gwinnett

County

Study area

Upper Alcovy River

EXPLANATION

Watershed

Upper Apalachee 

 River

Redland–Pew Creek

Shoal Creek

Yellow River

70 Groundwater Conditions and Studies in Georgia, 2008–2009

Monitoring of Groundwater and Surface-Water 

Resources in the City of Lawrenceville Area

Study Chief John S. Clarke

Cooperator City of Lawrenceville, Georgia

Year Started 2002

Problem

To meet Lawrenceville’s growing need for water, the 

city is expanding development of its groundwater supply. 

During 1995–2007, Lawrenceville obtained 4–7 percent 

of its drinking water from groundwater (from a single 

well); the remainder of the drinking water was obtained 

from surface-water sources. In addition to a well near 

the center of town, the city plans additional groundwater 

withdrawal in the Redland–Pew Creek and upper Alcovy 

River watersheds. To enable informed decisions, city 

managers want to be able to quantify the effects (if any) of 

groundwater pumping on the surface-water resources as 

development increases. In addition to understanding groundwater resources, successful watershed management requires 

an understanding of how stream water quality is affected by 

watershed characteristics. 

To support long-term management goals, the City of 

Lawrenceville, in cooperation with the U.S. Geological 

Survey (USGS), established a hydrologic monitoring 

network. The network consists of groundwater (regolith 

and bedrock wells) and surface-water (streamgages) sites in 

the two newly developed watersheds and in a background 

watershed (upper Apalachee River watershed) that is not 

influenced by the main pumping centers. In addition, sites 

in the Yellow River watershed are monitored to provide an 

indication of changes along the northern boundary of the 

Redland–Pew Creek watershed. An additional streamgage 

was installed in the adjacent Shoal Creek watershed. The 

data and information collected during the study can be used 

by local resource managers to develop a sustainable groundwater supply while minimizing the effects on surface-water 

resources. The data also will help in understanding changes 

in surface-water quality over time.

Objectives

A cooperative water program (CWP) between the USGS 

and the City of Lawrenceville has been in place since 1994. 

The initial purpose of the CWP was to provide a better understanding of the geologic controls on groundwater availability 

in fractured crystalline rock. In 2002, the program was 

modified to incorporate groundwater and stream monitoring 

to assess the effects of groundwater development. Stream 

water-quality monitoring was added to the program in 2005. 

Progress and Significant Results, 2008–2009

• Monitored groundwater levels in 26 wells, 3 of which 

recorded continuously, 21 wells were measured periodically, 

and 2 wells were continuously monitored during part of 

the year and measured periodically during the remainder 

of the year. 

• Monitored streamflow and precipitation continuously 

at three sites, two of which included continuous waterquality monitoring of water temperature, specific 

conductance, and turbidity. In addition to these three 

continuously monitored surface-water sites, the network 

included periodic streamflow measurements at 22 other 

sites (the number of locations measured in a given year 

varied over the reporting period).

• Collected synoptic stream base-flow measurements in 

September 2008 to locate and quantify gains or losses 

to streamflow resulting from groundwater interaction 

(groundwater seepage). Measurements were not collected 

during the fall of 2009 because of above-normal 

precipitation and high streamflows.

• Collected borehole geophysical logs in well 13FF34, 

a 605-foot-deep test well drilled by the City of 

Lawrenceville in June 2008 to explore additional water 

resources in the Redland–Pew Creek watershed. 

• Published study results in USGS Scientific Investigations 

Report 2010–5032, “Hydrologic conditions, stream-water 

quality, and selected groundwater studies conducted in the 

Lawrenceville area, Georgia, 2003–2008.”

• Updated the project Web site, which can be accessed at 

http://ga.water.usgs.gov/projects/lawrenceville/.

Reference

Clarke, J.S., and Williams, L.J., 2010, Hydrologic 

conditions, stream-water quality, and selected groundwater studies conducted in the Lawrenceville area, 

Georgia, 2003–2008: U.S. Geological Survey Scientific 

Investigations Report 2010–5032, 55 p.; available online 

at http://pubs.usgs.gov/sir/2010/5032/.
29

120

20

124

Blank where data are missing

Average 

2006–2008

(3.25 inches)

Average

2003–2005 

(4.42 inches)

LAWRENCEVILLE

City limit

City limit

13FF34

13FF18

13FF16

13FF13

Reach RP-5

Redland

Creek

Pew

Creek

0 1 MILE

0 1 KILOMETER 0.5

0.5

Existing or proposed 

 bedrock production well 

Yellow

River

Monthly precipitation,

in inches

0 

2 

4 

6 

8 

10 

12 

Well 13FF13 (periodic, Redland–Pew Creek watershed)

Well 13FF16 (periodic, Redland–Pew Creek watershed)

2003 2004 2005 2006 2007 2008

–10 

0 

10 

20 

30 

40 

50 

60 

–10 

0 

10 

20 

30 

40 

50 

60 

Drawdown due to

water sampling

Water level above (–) and below 

land surface, in feet

10 gal/min gained in this unit

Air lifting approximately 22 gal/min

10 gal/min gained in this unit

Air lifting approximately 

 10 to 12 gal/min

Land

surface

Natural 

gamma, 

in APIU

Lateral

resistivity, in 

ohm-meters

100

200

300

400

500

600

Feet Lithology

Caliper,

in inches

Base modified from U.S. Geological Survey

1:24,000-scale digital raster graphics

Reach RP-5

–0.25

0.25

0.50

–0.5

0

9/8/2003 10/28/2004 9/12/2005 9/5/2006 10/17/2007 9/8/2008

+25 percent error

Estimated groundwater seepage

–25 percent error

Groundwater seepage,

in million gallons per day

Groundwater level and streamflow monitoring data are used to evaluate 

effects of groundwater pumping in the Lawrenceville area. In the 

Redland–Pew Creek watershed during 2003–2007, groundwater levels in 

wells 13FF13 and 13FF16 showed a similar, slightly downward trend in 

response to decreased precipitation. In 2008, water levels in well 13FF16 

showed little change, whereas well 13FF13 showed a sharp decline of 

nearly 37 ft. This sharp decline was in response to the initiation of pumping 

in well 13FF18, located about 0.3 mile west of well 13FF13. In reach RP-5 

along Redland Creek, streamflow gain was indicated throughout 2003–2008, 

with a decrease related to low precipitation during the drought period of 

2006–2008. There was no appreciable difference in streamflow gain since 

the initiation of pumping in well 13FF18 (modified from Clarke 

and Williams, 2010).

Well 13FF34 is a 605-ft-deep test well drilled by the City of 

Lawrenceville in June 2008 to explore additional water resources in 

the Redland–Pew Creek watershed. Borehole geophysical logs and 

examination of drill cuttings indicate the rocks penetrated by this 

well include an upper and lower amphibolite unit, biotite gneiss and 

button schist unit, a quartzite/schist unit and a pegmatite/granite 

unit. Four water-bearing zones provide water to this well: (1) within 

the upper amphibolite unit, (2) near the contact of the upper 

amphibolite unit and the biotite gneiss and button schist unit, 

(3) within the quartzite/schist unit, (4) near the basal contact of the 

lower amphibolite unit. The final air-lift yield was measured at about 

22 gal/min (gallon per minute; APIU, American Petroleum Institute 

Units; modified from Clarke and Williams, 2010).

Amphibolite

Air lifting approximately

 1 to 2 gal/min

Biotite gneiss with button schist

(shearing)

Quartizite/schist

5,000

Pegmatite/granite

Water-bearing zone

Amphibolite

Schist/quartzite/biotite gneiss

Fracture near contact 

 approximately 2 to 3 gal/min

Biotite schist/schistose-biotite gneiss

Biotite gneiss and button schist

Biotite gneiss

Approximate location of water-bearing zone 

 based on air-lift yield during drilling

5 7 0 700 0

EXPLANATION

EXPLANATION

EXPLANATION

N

Surface-water station

Groundwater monitoring well River reach

Redland–Pew

Creek watershed

Selected Groundwater Studies in Georgia, 2008–2009 71
Area maps A and B

facing page

GEORGIA

72 Groundwater Conditions and Studies in Georgia, 2008–2009

Georgia Agricultural Water-Use Project

Study Chief Lynn J. Torak

Cooperator Georgia Soil and Water Conservation 

 Commission

Year started 2008

Introduction

By the end of 2009, agricultural water withdrawals 

in south Georgia were being monitored from a network of 

6,985 annually read flow meters and 148 daily reporting, 

satellite-transmitted, telemetry sites (see map A, facing page). 

The monitoring is a result of the enactment of House 

Bill 579 by the Georgia General Assembly on June 4, 2003, 

which granted jurisdiction to the Georgia Soil and Water 

Conservation Commission (Commission) to “[implement] 

a program of measuring farm uses of water in order to 

obtain clear and accurate information on the patterns and 

amounts of such use, which information is essential to proper 

management of water resources by the state and useful to 

farms for improving the efficiency and effectiveness of their 

use of water, ..., and [for] improving water conservation” 

(Georgia General Assembly, 2003).

Since November 2008, the U.S. Geological Survey, 

in cooperation with the Commission, has been researching 

methods for estimating agricultural water use and growingseason pumping rates through the analysis of water-meter 

data. A geographic information system (GIS) has been used 

for geospatial analyses of the data and has yielded promising 

results for identifying seasonal pumping patterns.

Objectives

Objectives of the analysis were to (1) develop a qualityassurance program to ensure completeness and internal 

consistency of water-meter data, (2) calculate descriptive 

statistics of aggregated water-use data, (3) evaluate the 

potential to relate daily water-use telemetry to annually 

reported water use through a descriptive statistical model, 

and (4) identify spatial and temporal distributions of 

agricultural-irrigation pumpage

Progress and Significant Results

A GIS-compatible relational database was developed 

consisting of all annually reported and satellite-transmitted 

telemetry of agricultural water use for aggregated statistical 

evaluation and comparison by source (groundwater, surfacewater, and well-to-pond irrigation systems). Quality-assurance 

checks indicated water-meter “rollback” or “roll forward” 

during periods of non-irrigation, and zero water use at some 

meter sites since the inception of the metering program 

in 2003; zero water use significantly affected calculations 

of mean annual water use. On average, irrigation volume 

supplied by groundwater exceeded the volume supplied 

by surface water by about one-third. Comparison of mean 

irrigation volumes by source indicated that groundwater and 

surface-water use represent two distinct data populations that 

require independent statistical analyses.

Analyses of 81 telemetered and 4,357 annually reported 

water-use sites, which constitute the metering program in the 

Chattahoochee–Flint River basin, were conducted to evaluate 

the randomness of the two datasets (groundwater and surface 

water)—a prerequisite for subsequent geospatial analyses—

and to assess the spatial distribution of meter locations. The 

analyses indicated 

• Possible outliers or “hot spots” (clusters of high or low 

water-use values) that may relate to variations in aquifer 

yield, streamflow availability, soil type, crop patterns, 

rainfall and topography, requiring further identification 

and study. Separate hot-spot analyses for surface water 

(map B) and groundwater (map C) indicated geographic 

bands trending northwest to southeast of low-to-high 

agricultural water-use volume.

• Concentrated distributions (clustering) of telemetry 

sites in areas containing low-irrigation volumes, 

which resulted in underestimating annually reported 

mean water use with the telemetry network.

• A wide range of applied irrigation volumes among

meter sites, which required data conversion to per-acre

application rates by dividing irrigation volume by 

field acres 

Reference

Environmental Systems Research Institute, Inc., 2009, How 

hot spot analysis: Getis-Ord Gi* (Spatial Statistics) works: 

Environmental Systems Research Institute, Inc., release 9.2,

accessed March 24, 2010, at http://webhelp.esri.com/

arcgisdesktop/9.2/index.cfm?TopicName=How%20Hot%20

Spot%20Analysis:%20Getis-Ord%20Gi*%20(Spatial%20

Statistics)%20works.

Georgia General Assembly, 2003, HB 579—Water resources; 

farm uses; water-measuring device: Georgia General 

Assembly, accessed March 23, 2010, at http://www.legis.

state.ga.us/legis/2003_04/search/hb579.htm.
Base modified from 

U.S. Geological Survey

1:2,000,000-scale digital files

Satilla–Suwannee–

St Marys–Ochlockonee

Chattahoochee–Flint

Altamaha–Oconee–

Ocmulgee

Coosa–Tallapoosa–

Tennessee

Chattahoochee–Flint

Altamaha–Oconee–Ocmulgee

Satilla–Suwannee–

St Marys–Ochlockonee

Savannah–Ogeechee

ALABAMA

GEORGIA

GEORGIA

FLORIDA

EXPLANATION

B. Surface-water metered sites, 2009 C. Groundwater metered sites, 2009

< –2.57

 –2.57 to –1.96

1.66 to 1.96

1.97 to 2.58

> 2.58 

Annual hotspot Gi* Z score—

 Standard deviation

Telemetry

0 10 20 MILES

0 N 10 20 KILOMETERS

–1.95 to –1.66

–1.65 to 1.65

50 MILES

50 KILOMETERS

0 25

0 25

EXPLANATION

148 telemetered stations

6,985 annual meters 

N

A. Georgia agricultural water metering program, 2009

Base modified from 

U.S. Geological Survey

1:100,000-scale digital data

Enlarged area in 

maps B and C

Fall Line

Selected Groundwater Studies in Georgia, 2008–2009 73

Locations of agricultural water metering 

program sites in south Georgia, 2009, including 

(A) 6,985 annually read and 148 daily satellitetransmitted data sites, with pattern of statistic 

(Gi* Z scores, Environmental Systems Research 

Institute, Inc., 2009) indicating geographic 

clustering of low-to-high annual irrigation 

volumes (“hot spots”) applied to (B) surfacewater and (C) groundwater metered sites in 

the Chattahoochee–Flint River basin. The Gi* 

statistic defines a normal Z score (or standard 

score), which assesses the distribution of the 

annually reported water-use values about the 

mean. Statistically significant Z scores (less than 

−1.64 or greater than 1.65 standard deviations) 

of the Gi* statistic occur in areas containing 

clusters of either high (positive Z scores) or low 

(negative Z scores) irrigation water-use volume.
GEORGIA

Savannah

Brunswick

Augusta

Glynn County

Camden County

Chatham County

Continuous 

Real time

EXPLANATION

Monitored well

74 Groundwater Conditions and Studies in Georgia, 2008–2009

Groundwater Information and Project Support

Study Chief Michael F. Peck

Cooperator Georgia Department of Natural 

 Resources Environmental 

 Protection Division

 St. Johns River Water Management 

 District, Florida

Year Started 1938

Problem

Groundwater supplies about 22 percent of freshwater 

withdrawals in Georgia—more than 1.2 billion gallons 

per day during 2005. More than 1.9 million people are served 

by groundwater supplies, and 752 million gallons per day 

are withdrawn for irrigation (Fanning and Trent, 2009). The 

distribution and quality of groundwater are highly variable 

and directly related to geology and natural and human 

stresses. Monitoring groundwater levels and groundwater 

quality is essential for the management and development 

of this resource.

Objectives

• Collect groundwater-level and groundwater-quality data to 

assess the quantity, quality, and distribution of groundwater.

• Provide data to address water-management needs and 

evaluate the effects of national and local management and 

conservation programs.

• Contribute data to national databases that will be used 

to advance the understanding of regional and temporal 

variations in hydrologic conditions..

Progress and Significant Results, 2008–2009

• Continuous water-level recorders were operated in 

179 wells during 2008 and in 181 wells during 2009. 

Of the 181 wells, 30 are instrumented with real-time 

transmission (satellite relay) of continuous water-level 

records. During 2009 an additional well was instrumented 

with real-time equipment in the coastal area to monitor 

specific conductance, which brought the total to four 

wells being monitored for water quality. The data from 

these wells can be accessed through the National Water 

Information System (NWIS) database on the Web at 

http://waterdata.usgs.gov/ga/nwis/current/?type=gw.

• Periodic water-level measurements were made in 

more than 3,700 wells to define potentiometric surfaces 

and to assess long-term trends. 

• Water samples for chloride analyses were collected 

from 66 wells during 2008 and 60 wells during 2009 

in the Brunswick area, and from 4 wells in the Savannah 

area and 7 wells in Camden County during 2008–2009.

• During 2008–2009, borehole geophysical logs were 

collected in 11 wells in northern Georgia and in 22 wells 

in southern Georgia (map and table, facing page).

• Well-inventory, water-level, and geologic data were 

verified for entry into the NWIS database. Field 

inventories of well sites were conducted to assist projects, 

and 1,030 sites were added to the NWIS Groundwater 

Site Inventory to improve groundwater data coverage 

in the State. The NWIS database can be accessed on the 

Web at http://waterdata.usgs.gov/ga/nwis/inventory/.

References

Fanning, J.L., and Trent, V.P., 2009, Water Use in 

Georgia by county for 2005; and water-use trends, 

1980–2005: U.S. Geological Survey Scientific

 Investigations Report 2009–5002, 186 p.; available 

online at http://pubs.usgs.gov/sir/2009/5002/.

Peck, M.F., Painter, J.A., and Leeth, D.C., 2009, 

Ground-water conditions and studies in Georgia, 

2006–2007: U.S. Geological Survey Scientific 

Investigations Report 2009–5070, 86 p.; available 

at http://pubs.usgs.gov/sir/2009/5070/.
Augusta

50 MILES

50 KILOMETERS

0 25

0 25

N

33P029

32P007

33P028

36Q392

29AA42

See 

county

map

 above

30AA38

37Q162

37Q162

15L020

16K052

16K054

16K053

18M017

20K010

18M018

20M027

18K049

12DD27

12DD24

12DD28

12DD22 14DD217 12DD23

12DD26

14DD216

14DD213

14DD214

14DD215

12H020

12H022

12H021 18H073

17G029 16H075

EXPLANATION

Well and station name

HUNTER

ARMY

AIRFIELD

CHATHAM

COUNTY

Base modified from U.S. Geological Survey

1:2,000,000-scale digital files

Selected Groundwater Studies in Georgia, 2008–2009 75

A hydrologic technician from the Groundwater 

Information and Project Support unit is recording 

the discharge from a well at Augusta, Georgia, 

during a 24-hour aquifer test. The well is completed 

in the Dublin–Midville aquifer system. Photo by 

Michael D. Hamrick, USGS.

Hydrologic technicians set up a data logger and pressure 

transducer to monitor the stage at Hunter Army Airfield in 

Chatham County, Georgia. A tipping bucket rain gage has also 

been installed to record precipitation during the test period. 

Data were used to develop a hydrologic budget for the pond to 

help assess water-bearing potential as a source of irrigation 

supply. Photo by John S. Clarke, USGS.

Well locations where geophysical logs were collected 

during 2008–2009.

Wells where geophysical logs were collected, 2008–2009

County name Station name Well depth, in feet,

below land surface 

Ben Hill 18M018 265.0

Ben Hill 20M027 304.0

Berrien 20K010 485.0

Chatham 36Q392 1,168.0

Chatham 37Q162 903.0

Colquitt 16H075 342.0

Cook 17G029 306.0

Cook 18H073 210.0

DeKalb 12DD22 228.0

DeKalb 12DD23 183.0

DeKalb 12DD24 165.0

DeKalb 12DD26 183.5

DeKalb 12DD27 206.6

DeKalb 12DD28 172.6

Liberty 32P007 505.0

Liberty 33P028 1,300.0

Liberty 33P029 560.0

Mitchell 12H020 133.0

Mitchell 12H021 76.0

Mitchell 12H022 200.0

Richmond 29AA42 509.0

Richmond 30AA38 122.0

Rockdale 14DD213 622.0

Rockdale 14DD214 622.0

Rockdale 14DD215 725.0

Rockdale 14DD216 305.0

Rockdale 14DD217 305.0

Tift 16K053 244.0

Tift 18K049 622.0

Tift 18M017 230.0

Worth 15L020 738.0

Worth 16K052 725.0

Worth 16K054 520.0
76 Groundwater Conditions and Studies in Georgia, 2008–2009

Selected Groundwater Publications, 

Conferences, and Outreach, 2008–2009

Many reports, conference proceedings papers, and 

abstracts were published during 2008 and 2009 presenting 

results of U.S. Geological Survey (USGS) groundwater 

investigations in Georgia. Oral and poster presentations were 

given at various technical conferences and outreach events 

throughout the State. These publications and presentations 

provide results of investigations conducted in cooperation 

with State, Federal, and local agencies including the 

Georgia Department of Natural Resources (primarily the 

Environmental Protection Division); U.S. Department of 

Defense, City of Brunswick and Glynn County; Albany 

Water, Gas, and Light Commission; City of Lawrenceville; 

and Rockdale County. Most of the publications are available 

on the Web only and can be viewed and downloaded at

http://ga.water.usgs.gov/publications/.

Georgia Water Resources Conference for 2009

The biennial Georgia Water Resources Conference is 

co-sponsored by the USGS, and the results of several USGS 

investigations are highlighted. The 11th biennial conference 

was held at The University of Georgia in Athens during 

April 2009. Twenty-eight USGS papers and posters, 14 of 

which addressed groundwater investigations, were published in 

the conference proceedings (see bibliographic listing below).

Other Conferences and Outreach Events

During 2008–2009, USGS groundwater scientists 

participated in a variety of conferences and outreach events, 

including the following:

• Georgia Association of Water Professionals Spring 

Conference and Expo, April 2009

• Carl E. Kindsvader Symposium, April 2008

• Geological Society of America, October 2008 

and October 2009

• Sunbelt Agricultural Exposition, October 2008 

and October 2009

• Georgia CoastFest, October 2008 and October 2009

• Georgia Groundwater Association, various

• Future Farmers of America, 2009

• Environmental Flows: Water for People and Nature 

in the Southeast, 2008

• Lake Seminole Workshop, 2008

• U.S. Geological Survey–U.S. Army Corps of Engineers 

(USGS–USACE) Annual Program Meeting, 2009

• American Society of Civil Engineers, Environmental 

and Water Resources Meetings and Georgia Section 

Meetings, 2009

• Managing Georgia’s groundwater—A monitoring and 

modeling approach: Georgia Association of Environmental 

Professionals meeting, February 2009

Selected U.S. Geological Survey Reports 

and Conference Proceedings Articles 

U.S. Geological Survey Reports

Calhoun, D.L., Gregory, M.B., and Wyers, H.S., 2008, Algal 

and invertebrate community composition along agricultural 

gradients—A comparative study from two regions of the 

Eastern United States: U.S. Geological Survey Scientific 

Investigations Report 2008–5046, 33 p.; also available 

online at http://pubs.usgs.gov/sir/2008/5046/.

Cherry, G.S., and Clarke, J.S., 2008, Ground-water 

conditions and studies in the Brunswick–Glynn County 

area, Georgia, 2007: U.S. Geological Survey OpenFile Report 2008–1297, 42 p.; available online at

http://pubs.usgs.gov/of/2008/1297/. 

Dalton, M.S., Stewart, L.M., Ip, H.S., 2009, Occurrence of 

viable avian influenza viruses in water and bed sediments 

from selected water bodies along the Atlantic Flyway, 

February and May 2006 and January 2007: U.S. Geological 

Survey Open-File Report 2009–1161, 12 p.; available 

online at http://pubs.usgs.gov/of/2009/1161/.

Fanning, J.L. and Trent, V.P.; 2009a, Water use in Georgia 

by county for 2005; and water-use trends, 1980–2005: 

U.S. Geological Survey Scientific Investigations Report 

2009–5002, 186 p.; available online at http://pubs.usgs.gov/

sir/2009/5002/.

Fanning, J.L., and Trent, V.P, 2009b, Water use in Georgia by 

county for 2005; and water-use trends, 1980–2005: U.S. 

Geological Survey Fact Sheet 2009–3034, 4 p.; available 

online at http://pubs.usgs.gov/fs/2009/3034/.

Gordon, D.W., 2008, Ground-water conditions and studies 

in the Albany area of Dougherty County, Georgia, 2007:

 U.S. Geological Survey Open-File Report 2008–1328,

49 p.; available online at http://pubs.usgs.gov/

of/2008/1328/.

Gordon, D.W., 2009, Groundwater conditions and studies in 

the Albany area of Dougherty County, Georgia, 2008: U.S. 

Geological Survey Open-File Report 2009–1244, 54 p.; 

available online at http://pubs.usgs.gov/of/2009/1244/.
Selected Groundwater Publications, Conferences, and Outreach, 2008–2009 77

Gotvald, A.J., Feaster, T.D., and Weaver, J.C., 2009, 

Magnitude and frequency of rural floods in the southeastern 

United States, 2006—Volume 1, Georgia: U.S. Geological 

Survey Scientific Investigations Report 2009–5043, 120 p., 

available online at http://pubs.usgs.gov/sir/2009/5043/.

Gotvald, A.J., and Oberg, K.A., 2008, Acoustic Doppler 

current profiler applications used in rivers and estuaries by 

the U.S. Geological Survey: U.S. Geological Survey Fact 

Sheet 2008–3096, 4 p.; available online at http://pubs.usgs.

gov/fs/2008/3096/.

Holloway, O.G., and Waddell, J.P.; 2008, Design and operation 

of a borehole straddle packer for ground-water sampling 

and hydraulic testing of discrete intervals at U.S. Air Force 

Plant 6, Marietta, Georgia: U.S. Geological Survey 

Open-File Report 2008–1349, 24 p.; available online at 

http://pubs.usgs.gov/of/2008/1349/.

Knaak, A.E., and Joiner, J.K., 2008, Hydrologic streamflow 

conditions for Georgia, 2007: U.S. Geological Survey Fact 

Sheet 2008–3099, 4 p.; available online at http://pubs.usgs.

gov/fs/2008/3099/.

Knaak, A. E., Joiner, J. K., and Peck, M. F., 2009, Summary 

of hydrologic conditions in Georgia, 2008: U.S. Geological 

Survey Fact Sheet 2009–3109, 6 p.; also available online at

http://pubs.usgs.gov/fs/2009/3109/.

Landers, M.N., and Ankcorn, P.D., 2008, Methods to evaluate 

influence of onsite septic wastewater-treatment systems 

on base flow in selected watersheds in Gwinnett County, 

Georgia, October 2007: U.S. Geological Survey Scientific 

Investigations Report 2008–5220, 12 p.; available online at 

http://pubs.usgs.gov/sir/2008/5220/.

McCallum, B.E., Gotvald, A.J., and Landers, M.N., 2009, 

Historic flooding in South Georgia, March 27–April 3, 2009:

U.S. Geological Survey Fact Sheet 2009–3079, 2 p.; available online at http://pubs.usgs.gov/fs/2009/3079/.

Musser, J.W., 2008, Evaluation of floodplain modifications 

to reduce the effect of floods using a two-dimensional 

hydrodynamic model of the Flint River at Albany, Georgia: 

U.S. Geological Survey Scientific Investigations Report 

2008–5223, 12 p.; available online at http://pubs.usgs.gov/

sir/2008/5223/.

Peck, M.F., Leeth, D.C., and Hamrick, M.D., 2008, Well 

inventory and geophysical logging of selected wells in 

Troup County, Georgia, 2007–2008: U.S. Geological 

Survey Scientific Investigations Map 3058, 1 sheet; 

available online at http://pubs.usgs.gov/sim/3058/.

Peck, M.F., Painter, J.A., and Leeth, D.C., 2009, Groundwater conditions and studies in Georgia, 2006–2007: 

U.S. Geological Survey Scientific Investigations Report 

2009–5070, 86 p.; available online at http://pubs.usgs.gov/

sir/2009/5070/.

Riley, J.W., and Jacobson, R.B., 2009, Long-term stage, 

stage-residual, and width data for streams in the Piedmont 

physiographic region, Georgia: U.S. Geological Survey 

Open-File Report 2009–1205, 46 p.; available online at 

http://pubs.usgs.gov/of/2009/1205/.

U.S. Geological Survey, 2008, Georgia’s ground-water 

resources and monitoring network, 2008: U.S. Geological 

Survey Fact Sheet 2008–3072, 2 p.; available at 

http://pubs.usgs.gov/fs/2008/3072/.

U.S. Geological Survey, 2008, Borehole geophysical logging 

of water-supply wells in the Piedmont, Blue Ridge, and 

Valley and Ridge, Georgia: U.S. Geological Survey Fact 

Sheet 2007–3048, 4 p.; available online at http://pubs.usgs.

gov/fs/2007/3048/.

2009 Georgia Water Resources Conference 

Proceedings Papers

The following USGS papers were published in

Rasmussen, Todd, Carroll, D.G., and Georgakakos, Aris,

eds., 2009, Proceedings of the 2009 Georgia Water Resources 

Conference, April 27–29, 2009: Athens, Georgia, The University of Georgia, CD–ROM. All USGS papers also are 

available online at http://www.gwri.gatech.edu/conferences/

previous-gwrc-conferences/gwrc-2009/.

Buell, G.R., Calhoun, D.L., and Wehmeyer, L.L., 2009, 

Hydrologic and land-use/land-cover metrics used in 

ecological assessments of six U.S. Fish and Wildlife 

Service National Wildlife Refuges in the southeastern 

USA, 8 p. 

Cherry, G.C., 2009, Ground-water modeling and monitoring 

to manage chloride plume expansion in the Upper 

Floridan aquifer near Brunswick, Georgia, 2 p.

Clarke, J.S., 2009a, Assessment of hydrogeology and 

effects of pumping on water-bearing zones within and 

overlying the Upper Floridan aquifer, south-central 

Georgia, 3 p.

Clarke, J.S., 2009b, The Israeli red line—A possible way 

to manage ground-water conditions in Georgia?, 4 p.

Fanning, J.L., 2009, Effectiveness of water-management 

actions during droughts in the Chattahoochee River Basin, 

Metropolitan Atlanta area, poster. 

Gonthier, G.J., 2009, Conceptual model of ground-water 

flow in fractured-crystalline rock—A case study based 

on constant-discharge tests at U.S. Air Force Plant 6, 

Marietta, Georgia, 2003, 6 p.

Gotvald, A.J., Weaver, J.C., and Feaster. T.D., 2009, 

Magnitude and frequency of floods in rural basins of 

Georgia, South Carolina, and North Carolina, 1 p.
78 Groundwater Conditions and Studies in Georgia, 2008–2009

Hall, M.E., and Holloway, O.G, 2009, Impact of declining 

water levels on domestic wells in south-central 

Georgia, 1 p.

Horowitz, A.J., 2009, An update on sediment studies 

associated with the City of Atlanta long-term monitoring 

program, 6 p.

Hughes, W.B., and Moon, C., 2009, Assessment of pesticides 

in urbanized watersheds of the Atlanta Metropolitan area, 

Georgia, 4 p. 

Joiner, J.K., 2009, Comparison of automated hydrograph 

separation methods in a Metropolitan Atlanta, Georgia, 

watershed, 2 p.

Jones, L.E., 2009, Temporal and spatial variation of 

simulated effects on base flow of increased ground-water 

pumping in the Lower Apalachicola–Chattahoochee–

Flint River Basin, 1 p.

Knaak, A.E., 2009, U.S. Geological Survey 

Georgia Water Science Center streamflow gaging network 

in Cobb County, Georgia, poster.

Knaak, A. E., and Joiner, J.K., 2009, Hydrologic streamflow 

conditions for Georgia, 2007, 2 p. 

LaFontaine, J., 2009, Hydrologic characteristics of watersheds 

in Metropolitan Atlanta, Georgia, 2003–2007, 3 p.

Landers, M.N., and Ankcorn, P.D., 2009, Influence 

of septic wastewater-treatment systems on base 

flow in southeastern Gwinnett County, Georgia, 

October 2007, 6 p.

Lawrence, S.J., 2009, Occurrence of organic wastewaterindicator compounds in the urban streams of Atlanta, 

Georgia, 2003–2006, 6 p. 

Leeth, D.C., 2009, Using the World Wide Web to assess 

current ground-water conditions in Georgia, 2 p.

Musser, J.W., 2009, Evaluation of floodplain modifications 

to reduce the effect of floods using a two-dimensional 

hydrodynamic model of the Flint River in Albany, 

Georgia, poster.

Payne, D.F., 2009, Simulated effects of sea-level rise on 

saltwater intrusion in the Upper Floridan aquifer at 

Hilton Head Island, South Carolina, 2 p.

Peck, M.F., Leeth, D.C., Hamrick, M.D., 2009, Well 

inventory and geophysical logging of selected wells in 

Troup County, Georgia, poster.

Peters, N.E., and Aulenbach, B.T., 2009, Hydrologic 

pathway contributions to stream fluxes of weathering

 products at Panola Mountain Research Watershed, 

Georgia, 8 p.

Riley, J.W., 2009, Assessing channel change using USGS 

stream gaging data. 2 p.

Torak, L.J., 2009, Effects of climate and pumpage on the 

ground-water level of the Upper Floridan aquifer in the 

Aucilla–Suwannee–Ochlockonee River Basin, southcentral Georgia, 8 p.

Torak, L.J., and Sanders, J.H., 2009, New evidence of 

leakage from Lake Seminole into karst limestone and the 

Apalachicola River near Chattahoochee, Florida, 6 p.

Walls, C.B., Cressler, A.M., and Stayton, W.L., 2009, 

Real-time water-level and specific conductance monitoring 

of saltwater contamination in the Upper Floridan aquifer, 

Brunswick, Georgia, poster.

Williams, L.J., 2009, Revised hydrostratigraphy of the 

Upper Floridan aquifer in South-Central Georgia—Insights 

gained through flowmeter logging, 4 p. 

Williams, L.J., and Gonthier, G.J., 2009, Movement and 

discharge of trichloroethene to streams near U.S. Air Force 

Plant 6, Marietta, Georgia, 6 p.
Appendix. Regression Statistics

Water-level trends in this report were estimated by applying the Levenberg–Marquardt 

Algorithm (LMA; Moré, 1978) to monthly mean water-level data for the period of record and 

during 2008–2009. Although the LMA typically is used for nonlinear fitting, it also can be used 

for deriving linear fits very near values derived using ordinary least squares fitting. In concept, 

LMA works by optimizing a mathematical function (called a merit function by statisticians) 

that measures how well the function represents the data. In this report, the merit function is 

the weighted sum of the squares of the differences (informally known as chi-squared and 

represented in equations and tables as χ2). 

In this report, the steps involved in minimizing this merit function are as follows:

1. Estimate a value for the slope and intercept, and calculate a line based 

on this estimate.

2. Calculate how far this line lies from the data (using the χ2). Adjust the line 

so that it lies closer to the center of the data. 

3. Repeat this until adjustments no longer affect the χ2 value.

Each step is completed through manipulations of algebraic matrices, that are beyond the scope 

of this report, but are fully explained in Moré, (1978).

Summary statistics for the straight line (linear) fits of water-level trends described in the 

main body of the report are provided here as an indicator of goodness of fit (Janert, 2010), and 

so that readers can make decisions based on their tolerance for risk. These include:

• The degrees of freedom representing the number of data points minus the variables used. 

For this evaluation, two variables are used—slope (m) and intercept (b). A general rule of 

thumb is that the residuals and the χ2 should be in the same order of magnitude, for the fit 

to be reasonable (with some exceptions).

• The root mean square error (RMSE) of the residuals is the square root of the average squared 

distance of a data point from the fitted line. RMSE units are in the same units as the quantity 

being estimated (in this report, feet).

• The chi-squared is the sum of squared residuals (differences) between the monthly mean 

water level and the values computed by the algorithm after the final iteration. Thus, the term 

“least-squares” fitting. The χ2 from the fit along with χ2 distribution tables may be used to 

estimate confidence intervals.

• The standard error (SE) of a variable (m or b in this report), expressed as a percentage, is 

a measure of how well m or b has been estimated and affects the location of the regression 

line. The greater the standard error, the greater the scatter around the regression line. In other 

words, standard error is a measure of dispersion. 

References

Janert, P.K., 2010, Gnuplot in action—Understanding data with graphs: Greenwich, 

Connecticut, Manning Publications Co., 360 p.

Moré, J., 1978, The Levenberg-Marquardt Algorithm—Implementation and theory,

in Watson, G.A., ed., Numerical analysis, v. 630: Berlin, Springer-Verlag, p. 105.
80 Groundwater Conditions and Studies in Georgia, 2008–2009

Table A–1. Regression statistics.

[%, percent]

Well

name

Period of record summary statistics 2008–2009 summary statistics

Degrees 

of

freedom 

Root mean 

square error 

of residuals

(RMSE)

Variance

 of

residuals

(χ2

)

Standard 

error of 

slope

(SEm %)

Standard 

error of

 intercept 

(SEb %)

Degrees 

of

freedom 

Root mean 

square error 

of residuals

(RMSE)

Variance

 of

residuals

(χ2

)

Standard 

error of 

slope

(SEm %)

Standard 

error of

 intercept 

(SEb %)

03PP01 375 3.01 9.08 43.36 1.45 22 3.22 10.37 969.70 86.35

06F001 351 7.47 55.79 45.81 1.74 17 6.43 41.33 73.18 44.35

06G006 193 8.80 77.38 110.80 1.29 19 7.35 54.01 52.93 24.87

06K009 293 7.61 57.85 4.24 0.27 22 5.06 25.65 1,851.00 8.68

06K010 294 1.30 1.69 11.71 0.11 21 0.41 0.17 11.29 1.58

06S001 641 6.09 37.05 1.76 1.00 22 1.11 1.24 11.55 30.39

07H002 346 7.62 58.13 12.78 3.69 18 4.42 19.57 58.63 42.58

07H003 355 4.91 24.14 175.10 2.93 20 3.97 15.73 1,918.00 151.30

07KK64 150 3.81 14.54 43.60 2.00 22 3.00 8.99 27.88 16.74

07N001 530 3.44 11.82 1.35 0.13 22 3.26 10.60 20.75 4.66

08E038 89 0.79 0.62 29.50 0.91 19 0.40 0.16 39.67 5.13

08E039 91 1.27 1.62 771.10 2.76 22 1.07 1.15 79.38 37.54

08G001 393 8.47 71.73 42.42 1.64 22 6.84 46.80 40.09 25.11

08K001 362 9.32 86.84 71.45 5.48 22 8.29 68.64 131.90 95.31

09F520 477 3.00 8.99 20.08 0.39 22 2.25 5.08 39.18 11.02

09FF18 89 0.56 0.31 23.01 0.66 11 0.45 0.21 48.70 9.42

09G001 351 3.43 11.75 29.71 0.41 21 2.59 6.71 47.88 12.47

09G003 336 2.30 5.29 45.13 0.39 20 0.97 0.94 30.73 6.99

09M007 295 23.05 531.26 9.89 0.83 21 24.20 585.75 219.10 36.08

09M009 300 1.48 2.20 103.50 0.33 22 0.84 0.70 19.00 6.53

10DD02 431 1.69 2.86 5.72 1.32 22 1.29 1.66 42.54 21.49

10G313 463 5.35 28.67 23.65 0.61 21 3.47 12.02 44.39 14.96

10H009 136 5.68 32.31 44.52 1.97 22 6.03 36.42 47.04 24.63

10K005 306 1.80 3.24 15.93 0.51 19 2.93 8.61 89.23 28.05

11AA01 763 2.80 7.85 98.73 1.04 18 2.27 5.16 29.49 17.28

11FF04 355 0.38 0.15 4.89 0.32 22 0.42 0.18 33.37 11.48

11J011 345 3.69 13.61 15.24 0.55 22 2.22 4.92 21.86 9.48

11J012 342 3.61 13.05 42.04 0.48 22 3.54 12.53 64.15 17.77

11K003 139 1.05 1.11 223.20 1.39 22 4.14 17.16 22.88 15.27

11K005 362 4.29 18.39 1.54 0.39 22 0.91 0.84 101.70 3.53

11L002 452 15.58 242.67 4.05 0.79 17 13.52 182.83 122.60 32.11

11P014 291 17.52 306.80 9.07 1.09 15 6.82 46.52 23.67 12.61

11P015 296 1.69 2.84 30.88 0.28 18 0.97 0.95 30.51 6.37

12F036 520 5.87 34.44 7.60 0.26 17 1.39 1.93 24.71 3.11

12JJ04 464 1.52 2.31 10.50 0.34 21 1.13 1.29 23.82 8.36

12K014 330 3.95 15.58 31.37 0.56 21 3.67 13.45 64.68 19.48

12K141 161 6.81 46.31 36.82 2.04 22 3.67 13.47 17.67 11.50

12K180 84 3.96 15.65 126.80 5.51 20 4.12 16.95 56.17 28.84

12L019 362 8.70 75.67 12.96 0.74 10 3.39 11.46 42.63 15.22

12L020 357 14.43 208.33 26.28 0.69 14 10.04 100.74 213.30 39.42
Appendix. Regression Statistics 81

Table A–1. Regression statistics.—Continued

[%, percent]

Well

name

Period of record summary statistics 2008–2009 summary statistics

Degrees 

of

freedom 

Root mean 

square error 

of residuals

(RMSE)

Variance

 of

residuals

(χ2

)

Standard 

error of 

slope

(SEm %)

Standard 

error of

 intercept 

(SEb %)

Degrees 

of

freedom 

Root mean 

square error 

of residuals

(RMSE)

Variance

 of

residuals

(χ2

)

Standard 

error of 

slope

(SEm %)

Standard 

error of

 intercept 

(SEb %)

12L021 359 11.73 137.61 173.70 0.57 16 7.18 51.50 185.80 20.09

12L029 322 5.84 34.09 42.92 0.80 21 3.71 13.79 58.36 19.51

12L030 287 4.49 20.20 64.36 1.22 22 2.89 8.34 26.77 15.89

12L277 130 6.02 36.24 209.20 2.72 21 3.92 15.39 21.91 14.16

12L370 107 4.23 17.88 207.10 2.18 21 3.82 14.59 40.72 17.84

12L373 88 4.24 17.94 127.00 3.74 22 4.09 16.73 44.15 19.56

12M001 341 11.64 135.49 6.14 0.65 17 8.81 77.54 70.88 55.64

12M002 345 13.88 192.67 11.26 0.58 15 8.57 73.41 104.30 20.16

12M017 326 4.77 22.73 58.41 0.94 22 2.43 5.91 99.80 20.60

12Z001 483 2.07 4.30 11.84 1.09 17 1.41 1.99 40.80 19.53

13FF30 67 1.07 1.15 14.92 2.22 17 1.20 1.44 193.00 14.94

13FF31 66 1.04 1.08 20.77 2.33 22 0.81 0.65 23.46 7.34

13J004 377 4.49 20.18 12.48 0.56 22 2.85 8.14 35.76 11.75

13K014 323 4.64 21.53 30.17 0.88 19 4.39 19.24 84.12 28.54

13L002 599 17.20 295.76 2.96 0.74 22 7.25 52.63 87.87 15.55

13L011 382 6.54 42.72 28.73 0.54 18 1.67 2.78 27.59 6.89

13L012 388 3.69 13.60 50.84 0.53 22 3.57 12.77 58.98 18.40

13L013 367 8.91 79.31 71.72 0.52 18 0.48 0.23 5.27 2.75

13L015 358 9.18 84.36 10.89 0.60 21 3.52 12.39 136.30 13.43

13L049 284 5.85 34.20 44.80 1.11 19 4.04 16.34 45.41 21.55

13L180 137 5.11 26.11 344.90 1.15 22 2.42 5.86 30.15 9.77

13M005 352 5.10 26.03 13.58 2.18 20 4.17 17.39 385.10 71.30

13M006 353 6.51 42.35 41.32 4.02 21 6.76 45.75 147.40 85.60

13M007 351 2.10 4.40 234.10 1.55 21 1.52 2.30 137.60 41.78

14GG02 70 1.02 1.05 12.22 0.54 16 0.91 0.84 47.03 3.39

14P014 302 3.59 12.89 7.85 0.46 21 1.49 2.23 27.11 7.06

14P015 299 9.29 86.26 23.42 2.47 19 10.08 101.56 80.86 52.98

15L020 442 1.19 1.42 0.78 0.04 20 0.72 0.52 33.46 1.10

15Q016 76 8.02 64.37 66.34 5.95 22 7.43 55.25 147.30 31.04

16MM03 258 0.64 0.41 17.84 0.93 22 0.51 0.26 37.28 18.18

18H016 527 1.56 2.44 1.63 0.05 22 1.04 1.07 26.63 1.70

18K049 367 3.22 10.38 2.14 0.16 15 3.33 11.10 4,515.00 8.10

18T001 335 1.35 1.82 3.82 0.14 21 1.00 1.00 50.22 5.48

18U001 406 1.10 1.21 4.80 0.04 17 0.90 0.81 101.60 1.95

19E009 613 6.83 46.66 15.54 0.31 22 6.15 37.84 76.71 12.71

21BB04 270 2.07 4.30 9.51 2.95 22 1.86 3.44 47.11 30.05

21T001 536 3.88 15.08 19.76 0.71 22 3.58 12.83 713.80 35.42

21U004 333 0.70 0.49 1.47 0.10 22 0.49 0.24 75.02 3.61

23X027 291 4.26 18.11 3.92 0.10 21 2.62 6.85 10.63 2.53

24V001 338 1.00 1.01 1.10 0.05 15 0.84 0.71 124.10 2.38
82 Groundwater Conditions and Studies in Georgia, 2008–2009

Table A–1. Regression statistics.—Continued

[%, percent]

Well

name

Period of record summary statistics 2008–2009 summary statistics

Degrees 

of

freedom 

Root mean 

square error 

of residuals

(RMSE)

Variance

 of

residuals

(χ2

)

Standard 

error of 

slope

(SEm %)

Standard 

error of

 intercept 

(SEb %)

Degrees 

of

freedom 

Root mean 

square error 

of residuals

(RMSE)

Variance

 of

residuals

(χ2

)

Standard 

error of 

slope

(SEm %)

Standard 

error of

 intercept 

(SEb %)

25Q001 510 2.16 4.68 1.33 0.15 22 2.08 4.32 30.71 5.87

26R001 426 3.20 10.21 1.89 0.11 22 3.26 10.65 125.10 5.48

27E004 361 2.52 6.33 12.90 0.22 22 1.07 1.14 34.57 4.16

27G003 339 2.63 6.93 8.27 0.16 22 1.42 2.02 51.45 3.98

28X001 348 2.07 4.28 1.90 0.20 22 1.76 3.09 33.17 9.73

29AA09 152 1.36 1.84 8.46 0.17 22 0.44 0.19 30.74 1.85

30AA04 353 2.26 5.09 4.08 0.11 22 0.71 0.51 130.90 1.75

30L003 425 3.43 11.74 3.14 0.24 18 1.66 2.77 49.36 5.33

31U008 313 3.39 11.48 4.54 0.25 22 2.59 6.73 81.28 10.38

31U009 320 3.18 10.12 4.32 0.25 20 2.11 4.45 72.52 9.08

32G047 65 1.43 2.05 11.42 7.03 22 0.43 0.18 14.70 21.25

32L005 133 1.02 1.05 2.85 0.16 22 0.30 0.09 25.52 1.72

32L015 312 2.53 6.41 10.25 0.26 22 1.64 2.69 44.07 7.04

32L016 316 1.55 2.37 5.97 0.17 21 0.59 0.34 452.40 3.25

32L017 309 1.54 2.37 7.35 0.23 22 0.81 0.65 73.58 5.45

32Y030 148 0.99 0.98 4.61 0.10 13 0.56 0.32 115.20 3.39

32Y031 164 1.42 2.01 5.06 0.17 22 0.95 0.90 213.20 4.21

32Y033 158 5.04 25.45 7.74 1.41 22 7.46 55.70 195.40 67.56

33D069 183 6.46 41.79 5.91 9.28 20 1.18 1.40 45.62 35.58

33D071 134 4.77 22.79 5.30 7.69 22 0.28 0.08 16.20 38.04

33D072 138 1.44 2.06 8.64 3.24 19 0.46 0.21 22.38 16.51

33D073 116 7.64 58.41 8.92 46.01 22 0.80 0.64 25.40 20.13

33D074 77 1.62 2.64 20.82 1.78 22 0.72 0.52 23.09 9.78

33E027 361 3.40 11.55 15.17 0.98 22 1.04 1.09 27.54 31.22

33H127 537 4.34 18.81 29.57 27.96 16 1.80 3.25 35.67 36.86

33H133 528 4.54 20.60 5.58 4.77 13 2.94 8.67 71.39 64.43

33H188 325 2.87 8.23 20.45 2.42 19 0.98 0.97 46.30 28.02

33H206 306 3.30 10.86 9.80 3.70 22 1.38 1.91 31.58 55.24

33H207 303 3.81 14.51 5.99 48.12 21 1.46 2.14 58.34 60.90

33H208 303 1.38 1.91 6.66 2.32 22 0.61 0.37 20.40 15.91

33H324 33 1.95 3.79 22.56 12.41 22 1.80 3.23 28.35 18.15

33H325 33 7.15 51.12 33.63 13.84 22 6.88 47.37 32.03 18.42

33J044 363 2.64 6.96 17.52 26.36 21 1.05 1.11 18.82 18.10

33J062 107 2.74 7.49 24.07 4.13 22 0.65 0.42 61.75 15.33

33J065 97 1.18 1.38 9,726.00 285.30 17 0.11 0.01 12.49 9.79

33M004 498 2.93 8.56 2.49 0.32 22 1.31 1.72 32.86 5.88

33R045 90 3.43 11.75 34.71 1.70 22 1.66 2.75 40.56 6.58

34G033 59 2.21 4.87 12.28 4.68 21 1.08 1.16 28.73 87.47

34H334 492 3.43 11.78 6.48 7.86 19 1.37 1.88 34.48 46.85

34H371 507 2.87 8.23 7.30 3.79 22 1.31 1.70 36.01 70.07
Appendix. Regression Statistics 83

Table A–1. Regression statistics.—Continued

[%, percent]

Well

name

Period of record summary statistics 2008–2009 summary statistics

Degrees 

of

freedom 

Root mean 

square error 

of residuals

(RMSE)

Variance

 of

residuals

(χ2

)

Standard 

error of 

slope

(SEm %)

Standard 

error of

 intercept 

(SEb %)

Degrees 

of

freedom 

Root mean 

square error 

of residuals

(RMSE)

Variance

 of

residuals

(χ2

)

Standard 

error of 

slope

(SEm %)

Standard 

error of

 intercept 

(SEb %)

34H391 399 2.82 7.94 8.34 2.84 20 1.39 1.92 32.36 55.03

34H436 310 2.92 8.55 11.86 2.01 22 1.21 1.45 29.14 96.02

34H437 298 2.09 4.39 10.12 286.80 21 0.92 0.84 63.33 51.45

34H492 119 1.06 1.13 38.80 4.59 22 0.75 0.57 30.10 20.78

34H495 88 2.85 8.13 9.29 7.15 21 0.94 0.88 21.66 85.01

34H500 102 3.52 12.38 218.40 6.61 20 1.14 1.31 21.30 58.57

34H515 48 0.52 0.27 200.70 14.44 17 0.42 0.18 64.39 28.20

34J077 136 3.77 14.18 10.15 2.99 22 2.58 6.65 39.52 18.35

34J080 90 2.33 5.42 21.19 92.57 22 1.19 1.42 28.74 20.11

34J081 88 1.60 2.57 47.25 3.70 22 1.27 1.62 34.50 14.93

34J082 90 0.89 0.80 49.25 4.10 22 0.50 0.25 43.80 14.19

34K104 52 2.44 5.94 54.27 6.13 22 0.71 0.51 23.84 5.59

34N089 508 3.00 9.03 2.18 0.70 22 1.33 1.78 24.04 9.17

34S008 98 1.22 1.49 25.17 1.02 22 0.46 0.21 9.48 3.29

34S011 90 3.14 9.89 43.63 1.35 22 1.46 2.14 45.38 5.40

35H077 52 4.45 19.81 747.70 19.21 22 4.17 17.41 92.90 40.12

35M013 506 2.52 6.34 2.13 0.65 22 0.91 0.83 19.16 7.02

35P094 807 2.23 4.96 78.57 2.12 22 1.36 1.86 51.04 31.44

35P110 111 3.10 9.60 223.30 2.10 22 1.62 2.26 26.05 10.16

35P109/125 108 3.08 9.46 62.41 2.00 19 1.64 2.70 27.90 10.58

35Q050 47 2.16 4.65 24.19 3.81 21 0.68 0.46 24.77 8.31

35S008 115 1.39 1.94 16.49 0.50 22 0.53 0.29 18.59 2.82

35T003 112 3.38 11.40 48.79 1.64 22 2.02 4.09 64.41 12.71

35T005 107 2.24 5.02 5,375.00 1.72 22 1.27 1.61 56.87 10.91

36N012 121 2.40 5.75 43.04 0.91 22 1.33 1.77 27.26 7.32

36Q008 660 11.29 127.38 17.03 0.66 22 4.71 22.19 35.26 11.59

36Q020 603 4.47 19.99 2.28 0.52 20 2.49 6.22 36.50 12.11

37P114 307 2.93 8.58 10.25 0.35 22 2.52 6.36 29.30 10.56

37P116 304 0.30 0.09 26.04 0.22 21 0.36 0.13 104.10 12.15

37Q016 647 8.29 68.69 56.25 0.58 22 4.45 19.79 35.65 12.73

37Q185 247 5.51 30.38 3.40 0.36 17 7.53 56.75 52.32 19.33

37Q186 67 1.89 3.56 15.43 2.68 21 0.87 0.76 14.08 3.47

38Q002 641 3.01 9.07 2.77 0.51 22 1.66 2.75 39.63 11.59

38Q201 274 1.31 1.72 8.31 0.15 22 0.76 0.58 23.52 3.89

38Q208 137 0.40 0.16 85.67 0.85 22 0.42 0.18 23.13 11.29

38Q209 141 0.32 0.11 14.14 0.46 22 0.36 0.13 152.90 14.53

39Q003 543 2.51 6.32 3.08 0.50 20 1.47 2.16 77.36 13.89

39Q024 159 1.30 1.68 15.13 0.34 22 1.02 1.05 30.71 6.74

39Q025 158 1.60 2.58 18.42 0.46 22 1.44 2.08 46.19 10.25

39Q026 152 0.50 0.25 62.52 0.46 21 0.48 0.23 284.50 12.91

39Q029 139 1.05 1.11 223.20 1.39 21 0.87 0.76 40.06 17.33
Manuscript approved for publication, March 21, 2011

Edited by Rebecca J. Deckard

Illustrations and layout by Bonnie J. Turcott

For more information concerning the research in this report, contact

USGS Georgia Water Science Center

3039 Amwiler Road, Suite 130

Atlanta, Georgia 30360

telephone: 770-903-9100

http://ga.water.usgs.gov
Peck, M.F., Leeth, D.C, and Painter, J.A.—Groundwater Conditions and Studies in Georgia, 2008–2009—Scientific Investigations Report 2011–5048