The geology and water resources of the upper Suwannee River Basin, Florida ( FGS: Report of investigation 87 )
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Permanent Link: http://ufdc.ufl.edu/UF00001274/00001
 Material Information
Title: The geology and water resources of the upper Suwannee River Basin, Florida ( FGS: Report of investigation 87 )
Series Title: ( FGS: Report of investigation 87 )
Physical Description: x, 165 p. : ill., maps ; 23 cm.
Language: English
Creator: Ceryak, Ron
Knapp, Michael S
Burnson, Terry
Florida -- Bureau of Geology
Publisher: Florida Dept. of Natural Resources, Bureau of Geology
Place of Publication: Tallahassee
Publication Date: 1983
Subjects / Keywords: Geology -- Suwannee River Valley (Ga. and Fla.)   ( lcsh )
Hydrology -- Suwannee River Valley (Ga. and Fla.)   ( lcsh )
Suwannee River Water Management District (Fla.)   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: by Ron Ceryak, Michael S. Knapp, and Terry Burnson.
Bibliography: Bibliography: p. 116-120.
General Note: Published for the Bureau of Geology, Division of Resource Management, Florida Department of Natural Resources in cooperation with Suwannee River Water Management District.
 Record Information
Source Institution: University of Florida
Rights Management:
The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
Resource Identifier: aleph - 000460820
oclc - 10556333
notis - ACM3852
System ID: UF00001274:00001

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Elton J. Gissendanner, Executive Director

Casey J. Gluckman, Director

Charles W. Hendry, Jr., Chief



Ron Ceryak, Michael S. Knapp, and Terry Burnson

Published for the
in cooperation with



/km. 87



Secretary of State


Commissioner of Education

Attorney General


Commissioner of Agriculture

Executive Director


JULY 15, 1983

Governor Bob Graham, Chairman
Florida Department of Natural Resources
Tallahassee, Florida 32301

Dear Governor Graham:

The Bureau of Geology, Division of Resource Management, Depart-
ment of Natural Resources, is publishing as its Report of Investigation
No. 87, "The Geology and Water Resources of the Upper Suwannee
River Basin, Florida." The Suwannee River is one of the major stream
systems in Florida, as yet largely undeveloped. The information contained
in this report is an important contribution towards understanding the
geology and hydrology of this river, and its place in the region's

Respectfully yours,

Charles W. Hendry, Jr., Chief
Bureau of Geology

Printed for the
Florida Department of Natural Resources
Division of Resource Management
Bureau of Geology




S stract........................................................................... ..................... 1
Acknow ledgements.............................. ..........................3
Introduction ............................. ............. ....................................... 4
Purpose.............................. .......... ........................................... 4
Location ........................................................................ 4
M ethodology.....................................................................4
Climate........................................... ..................... 6
Metric Conversion Factors...................... ... ..................... 6
Geology-by M ichael Knapp.................................. ..............................8
Geologic Overview..................................... ........................ 8
Physiography ........................................................................... 9
Geologic Structure.................................. ............................. 11
Stratigraphy ................................................................. 14
Paleozoic Erathem .............................. .... ...... ..........................14
Mesozoic Erathem........................ .......... ........................18
Cretaceous System ............................ ... .......................... 18
Cenozoic Erathem ............................. ..... ............................. 18
Paleocene Series........................ .........................18
Eocene Series..................................... ...................... 18
Oligocene Series.................................. ...........................21
M iocene Series.............................................................. 21
Plio-Pleistocene Series........................................................ 27
Hydrogeology-by Ron Ceryak.............................................. ...................... 29
Hydrogeologic Overview .................................................................. .. 29
Surficial Aquifer................................................................ ......................32
Configuration and Extent..................................... ...... .....................32
Water Level Relationships and Fluctuations........................................... 34
Aquifer Properties........................... ...... ... ..... .................35
Groundwater Development....................................................................35
W ater Chem istry............................. ..... ..... ............................35
Secondary Artesian Aquifer................... ....... .. ....................39
Configuration and Extent................................................ .. 39
Water Level Relationships and Fluctuations........................................... 39
Aquifer Properties..................................... .............................43
Groundwater Development....................... .......................43
W ater Chemistry........................... .......................43
Flridan Aquifer..... ................................................................... .................44
Configuration and Extent................................. .. ......................... .. 44
Areas of Artesian and Nonartesian Conditions...........................................48
Potentiometric Surface Fluctuations............................ ....................... .. 52
W ater Level Relationships........................................................... 65
Aquifer Properties........................... ................ ............76
Groundwater Development..................... ........................84
W ater Chem istry.................................... ........ ........................84

Hydrology-by Terry Burnson................................................................... .... 38
Hydrologic Overview ...................................................................... .......... 38
Annual Peak Flow ............................................................................... 97
Low Flow s ........................... ................................ ........................... !00
Surfacew ater Chem istry ........................................................................ 106
Surfacewater Use, Impoundments, and Structures...................................... 112
Conclusions...... ........................... .. ......... .. ............................... 113
References ........................... ..... ...... .......... ......................116
Appendix A Geology............................................. ....... ...................... 121
A-1 Geologic Control Well Data ..................................................... 122
A-2 Measured Geologic Sections (Surface Outcrops)..................................126
A-3 Selected Florida Bureau of Geology Well Descriptions........................... 130
Appendix B Hydrogeology............................. .................. ....................... 140
B-1 Water Level Well Control Data................................. ........................ 141
B-2 Groundwater Quality Control Well Data............................................... 150
B-3 Pearson Product Moment Correlation Coefficients for Water
Quality Param eters............................. ................. ........................ 156
A ppendix C Hydrology.................................................................................. 157
C-1 Low Flow and Seepage Discharge Measurements on the Suwannee
River ................................................... ........................................ 158
C-2 Basic Statistical Analysis of Specific Water Quality Parameters at
Select Surfacewater Sites....................................... ........................ 162



Figure Page
1 Location of Study Area .......................................... ...................... 5
2 Physiographic Features........................................ .......................10
3 Major Structural Features of North-Central Florida and
South Georgia ................................................ ...................... 12
4 Geologic Cross Section................................................................ 1 6
5 Stratigraphic Data Points....................................... ..................... 17
6 Structural Top of Ocala Group....................... ......... .............. 20
7 Structural Top of Suwannee Limestone ........................................... 22
8 Location and Lithology of Surface Outcrops.....................................25
9 Structural Top of Hawthorn Formation ............................................ 26
10 Isopach of Combined Hawthorn Formation and
Plio-Pleistocene Deposits ................................ ...................... 28
11 General Hydrogeology.......................................... ...................... 30
12 Cluster Analysis of Water Quality Parameters...................................31
13 Extent of Surficial Aquifer...................................... ........... ................33
14 Hydrographs of Wells that Tap the Surficial Aquifer in
Osceola National Forest........................... .....................34
15 Means and Ranges of Parameter Values.......................................... 36
16 Piper Trilinear Diagram Groundwater.......................................... 38
17 Relationship of Secondary Artesian Water Levels to
Floridan Aquifer Water Levels at Osceola National
Forest............................... ............ ......... .......................... 41
18 Relationship of Secondary Artesian Water Levels to
Floridan Aquifer Water Levels at Occidental Chemical
Com pany................................................................... ....... 42
19 Inferred Depth to Base of Potable Water in Floridan Aquifer...............45
20 Structural Top of Floridan Aquifer...................................... ..........47
21 Artesian-Nonartesian Transition Zone Superimposed on
the Physiographic Map................................................... ........ 49
22 Artesian-Nonartesian Transition Zone Superimposed on
the Structural Top of the Floridan Aquifer..................................50
23 Artesian-Nonartesian Transition Zone Superimposed on
the Isopach of the Hawthorn Formation........................... ...51
24 River Basin and Climatological Region Boundaries for the
Suwannee River above the Withlacoochee, Alapaha,
and W ithlacoochee River Subbasins.......................................... 53
25 Potentiometric Surface of Principal Artesian-Floridan
Aquifer in South-Central Georgia and North-Central
Florida ............. .................................... .......... ................. 54
26 Potentiometric Surface of the Floridan Aquifer in North-
Central Florida, August 1977................................................... 55
27 Potentiometric Surface of the Floridan Aquifer in North-
Central Florida, November 1977............................................. 57
28 Net Change in the Potentiometric Surface of the Floridan
Aquifer in North-Central Florida, August to November 1977......... 58

29 Potentiometric Surface of the Floridan Aquifer in North-
Central Florida, February 1978...............................................
30 Net Change in the Potentiometric Surface of the Floridan
Aquifer in North-Central Florida, November 1977 to
February 1978 ....................................................................... 62
31 Potentiometric Surface of the Floridan Aquifer in North-
Central Florida, M ay 1978...................................... ............ 63
32 Net Change in the Potentiometric Surface of the Floridan
Aquifer in North-Central Florida, February to May 1978.............. 64
33 Mean Monthly Rainfall for the South-Central Georgia
Climatological Region (30-Year Mean) ....................................... 66
34 Seasonal Relation of Mean Monthly Precipitation, Evaporation,
Streamflow, and Groundwater Level, Valdosta Area...................67
35 Long-Term Relation of Precipitation, Streamflow, and
Groundwater Level, Valdosta Area, 1957-1975..........................68
36 Daily Groundwater Levels, Stream Discharge and Precipitation,
Valdosta Area, 1977................................................ ..............69
37 Groundwater Level Fluctuation, Valdosta, Georgia, and
Jennings, Florida 1968-1977................................... ........... 70
38 Daily Groundwater Level Fluctuation, Valdosta, Georgia,
and Jasper, Florida, June 1976 through November
1977...................................................... ......................... 72
39 Daily Groundwater Level Fluctuation at Jasper, Florida,
Compared with Daily Stage of Alapaha River near
Jennings, Florida, July 1976 through October 1977................. 73
40 Daily Groundwater Level Fluctuation at Valdosta, Georgia;
Fargo, Georgia; and Osceola National Forest,
Florida, 1977 ...................... ............................................. .. 74
41 Comparison of Stage of Suwannee River with Water
Levels in Three Wells Tapping the Floridan Aquifer
in Osceola National Forest ........................................... ...... 77
42 Long-Term Groundwater Level Fluctuation, Lake City,
Florida, 1948-1979.............................................. ... ...............78
43 Generalized Geology, Well Construction, and Static
Water Levels at Aquifer Test Site............................................80
44 Distance Versus Drawdown at Aquifer Test Site.........................8...1.
45 Theis Composite Curve Matching Method......................................32
46 Transmissivity Versus Specific Capacity in the Floridan
Aquifer in North-Central Florida................................................ 33
47 Relation of Parameters with Depth, Test Well 1,
Valdosta, Georgia ................................................................... 36
48 Location Map, Study Area, Surfacewater and Rainfall Stations............9
49 Location Map, Lakes, Ponds, and Springs........................................ 0
50 Hydrographs for Alapaha River near Jennings, Florida,
and Alapaha Rise, Florida................................. ................. 14
51 Monthly Means for Rainfall and Surfacewater Discharge
Stations........................................ ................................... 16


Pa! e

Fi, ure Page
52 Flood Frequency Curves for Select Surfacewater Stations................ 99
53- Flow Duration Curves for Select Surfacewater Stations................. 101
54 Seven-Day. Low Flow at Select Surfacewater Stations................... 102
55 Location Map, Seepage Run Measurement Sites..............................105
56 Piper Trilinear Diagram-Surfacewater..........................................108
57 Stage Versus Calcium Ion Concentration at Select
Stations on the Suwannee River............................................. 110
58 Stage Versus Specific Conductivity at Select Stations
on the Suwannee River.............................. .........................111


Table Page
1. Stratigraphic Nomenclature for Geologic Formations in the Upper
Suwannee River Basin............................................ .................... 15
2. Relationship of Lithologic and Geologic Units in Osceola National
Forest............................. ...................... .. .. ...........................24
3. Water Use in the Suwannee River above the Withlacoochee and
Alapaha River Subbasins................................ ............................ 32
4. Generalized Description of Hydrogeologic Units in Osceola National
Forest......................... ..... .... ... ........ .. ....................... 40
5. Mean Monthly Rainfall in Inches-Georgia 1977-1978................................52
6. Lakes and Ponds in the Upper Suwannee River Basin, Florida ....................91
7. Upper Suwannee River Basin Area Springs .............................................. 92
8. Monthly Mean Discharge for Select Surfacewater Stations........................93
9. Mean Monthly Rainfall in Upper Suwannee River Basin ...............................95
10. Annual Peaks Exceeding Flood Stage at White Springs and
Ellaville, Florida................................................. ....................................98
11. Extremes for Period of Record at Select Surfacewater Stations in Upper
Suwannee River Basin, Florida and Georgia........................................... 100
12. Lowest Average Flow for Suwannee River at Fargo, Georgia, and
W hite Springs, Florida....................................................................... 103
13. Lowest Average Flow for Suwannee River at Ellaville, Florida, and
Withlacoochee River near Pinetta, Florida.............................. ...........104


Ron Ceryak1, Michael S. Knapp2, and Terry Burnson'

The Okefenokee Swamp contains the headwaters of the Suwannee
River. The Upper Suwannee River Basin in Florida, excluding the major
tributaries (Alapaha and Withlacoochee), is approximately 855 square
miles. Upstream from White Springs, Florida, the Suwannee River is
superimposed on as much as 300 feet of confining sediments overlying
the Floridan Aquifer; and river flow is essentially dependent upon runoff.
Peak flows characteristically occur in the spring. The mean annual
discharge at Fargo, Georgia, is 1113 cubic feet per second (cfs); at White
Springs, Florida, it is 1879 cfs; and at Ellaville, Florida, it is 6960 cfs.
Since 1931 there have been at least 74 no-flow days recorded at Fargo,
Georgia. At White Springs and elsewhere downstream, base flow is
sustained by groundwater inflow. Stratigraphically segregated from the
carbonate aquifer, surfacewater quality in the Suwannee River above
White Springs reflects the influence of a poorly drained, heavily vegetated
environment. Water quality is acidic with low specific conductance, low
dissolved oxygen, and relatively low calcium and magnesium ion con-
centrations. At White Springs and continuing downstream, surfacewater
quality is influenced both by runoff and groundwater inflow. Magnesium
and calcium ion concentrations are relatively higher than those reported
upstream as are specific conductivity, pH, and alkalinity values.
The Upper Suwannee River Basin is located within the eastern seg-
ment of the Gulf of Mexico sedimentary province (Pressler, 1947). It
is within a transition zone between the North Gulf Coast sedimentary
province and the Florida Peninsula sedimentary province (Chen, 1965).
The Peninsular Arch is the dominant subsurface geologic structural
feature in the area. The oldest stratum encountered in well samples is
a black shale believed to be Silurian in age; however, the stratigraphic
column consists chiefly of carbonate rocks ranging in age from Upper
CrDtaceous through Tertiary.
Outcrops of the Suwannee Limestone, the St. Marks Formation, the
HEwthorn Formation, and the Undifferentiated Terrace Deposits are
de ;cribed. Structural contour maps were constructed for the tops of the
0( ala Group, Suwannee Limestone, Hawthorn Formation, and the
Fl ridan Aquifer hydrostratigraphic unit.
The major physiographic feature within the area is the Northern
Hi hands. The Northern Highlands is separated from the Gulf Coastal

wannee River Water Management District, Route 3, Box 64, Live Oak, Fl 32060.
Z F rmerly with Florida Bureau of Geology; now with South Florida Water Management
Dis rict, P.O. Box V, West Palm Beach, Fl 33402.


Lowlands by the Cody Scarp, which crests at approximately 110 fe t
above mean sea level (msl)
There are three aquifer systems in the study area. A perched, sur-
ficial aquifer mantles the Northern Highlands. This aquifer's water
chemistry displays high relative values for sodium and chloride. A secon-
dary artesian aquifer underlies the surficial aquifer and has high relative
concentrations of fluoride and orthophosphate. The artesian portion of
the Floridan Aquifer underlies the secondary artesian aquifer. Artesian
and nonartesian areas within the Floridan Aquifer are separated by the
Cody Scarp, a physical boundary that affects all of the hydrogeologic
units in the basin. Water from the artesian portion of the Floridan Aquifer
displays higher concentrations of all chemical constituents (except
nitrate) than water from the nonartesian portion of the Floridan Aquifer.
In artesian areas, water has been in contact with the rock longer and
is more nearly in chemical equilibrium with it. All Floridan waters in the
basin have high relative concentrations of calcium, magnesium, bicar-
bonate, alkalinity, sulfate, and high specific conductance.
The Valdosta, Georgia, region is the recharge area for the Floridan
Aquifer in the Upper Suwannee Basin in Florida. This area is a poten-
tiometric high with heads exceeding 100 feet above msl. Recharge areas
have the highest groundwater level fluctuation (33 feet/year at Jennings,
Florida), while groundwater levels under the confined highlands fluctuate
as little as three feet per year.
An aquifer test at Occidental Chemical Company (OXY) in Hamilton
County, Florida, indicates that the coefficient of transmissivity is about
190,000 ft2/day, and the coefficient of storage is about 0.001 for the
confined, artesian portion of the Floridan Aquifer.

The authors wish to thank the many local residents who permitted
us access to their property and use of their wells to examine the geology,
measure water levels, and take water samples. Special thanks to Pete
Deas and Stafford Scaff of Jasper, Ivey Prescott of Jennings, Santa Deas
and H. T. Reid of Bellville, and Dorothy Nott of Live Oak for allowing
us permission to install continuous recorders on their wells.
Thanks to the following well drillers who supplied invaluable informa-
tion: Dayton Everetts, Lake Park, Georgia; George Knight and Leonard
Bowers, Live Oak; and Pat and Buddy Lynch, Lake City.
Thanks to Occidental Chemical Company for the use of their facilities
to collect water samples and to conduct an aquifer test.
Thanks to the U.S. Geological Survey, Tallahassee Subdistrict, for
hydrologic and hydrogeologic data.
The authors are grateful to the following people for critical review
of the manuscript: Charles Tibbals, Rick Krause, Jim Miller, Dick
Johnston, Robert Hull, and Gilbert Hughes of the USGS; Sam Upchurch,
University of South Florida; Dan Spangler, University of Florida, and the
staffs of the SRWMD and Florida Bureau of Geology.
Thanks to Carolyn Mobley of the SRWMD for typing and editing the
many drafts, Patsy Beauchamp, SRWMD, for the data assimilation, and
Pat Batchelder, SRWMD for drafting the figures.



This study was undertaken to define the geologic, hydrogeologic,
and hydrologic characteristics of the Upper Suwannee River Basin in
Florida. The study was undertaken by the Suwannee River Water
Management District (SRWMD) in cooperation with the Florida Bureau
of Geology (FBOG).

The Suwannee River originates in south Georgia's Okefenokee
Swamp and flows south into Florida for 236 miles to the Gulf of Mexico.
The Suwannee River Basin is divided into Upper and Lower Basins. The
Lower Basin includes the Santa Fe River Subbasin and the Suwannee
River below Withlacoochee River Subbasin. The Upper Basin includes
the Alapaha River, Withlacoochee River, and Suwannee River above the
Withlacoochee River subbasins (Vanlier, et al., 1975).
The Suwannee River above the Withlacoochee includes the Oke-
fenokee Swamp and nearly 110 miles of river downstream to its con-
fluence with the Withlacoochee River in Hamilton County, Florida (Figure
1). This subbasin has a 2770 square mile drainage of which 855 square
miles are in Florida. The Alapaha River Subbasin has an 1840 square
mile drainage of which 110 square miles are in Florida. The study area
includes those parts of both subbasins that lie in Hamilton, Columbia,
Suwannee, and Baker counties in Florida as well as an eastern portion
of the Withlacoochee River Subbasin (70 square miles in Hamilton Coun-
ty). These and adjacent areas comprise an approximately 1450 square
mile study area (Figure 1).

Subsurface information was derived from existing FBOG well cut-
tings, cores, auger samples, geophysical logs, and drillers' logs (Appendix
A-1). Twenty-four auger holes were drilled and 52 surface outcrops along
the Suwannee, Alapaha, and Withlacoochee rivers were samples aid
analyzed (Appendix A-2). Stratigraphic sections were measured ir a
number of sinkholes.
Groundwater level fluctuations in the Floridan Aquifer w re
monitored quarterly in 107 wells (Appendix B-1). Continuous water le el
records were obtained from five wells (Appendix B-1). An aquifer tt st
was performed at Occidental Chemical Company (OXY) in Hamilt n
County to determine hydraulic properties of the Floridan Aquifer.
Water chemistry of each aquifer was established by sampling 1 '2
wells. Samples were analyzed for chloride (CI-), fluoride (F-), sulf< te
(SO4--), alkalinity, orthophosphate (o-P04--), nitrate (NO3-), calci mn
(Ca+ +), magnesium (Mg + +), sodium (Na +), potassium (K+), p-,
temperature, specific conductance, nitrite (NO2-), and ammonia (NH4-' )



j w


f OT H 0 M A ,;


K -






... i; ... ..

10 0 10 20 30 Miles

0 10 20 30 40 Kilometers



Figure 1. Location of study area.



Cluster diagrams, Piper Trilinear Diagrams, and means and ranges we-e
used to evaluate the chemical data.
Streamflow data were obtained at five U.S. Geological Survey
(USGS) continuous recorder stations and one wire weight station in tie
study area and were used to develop stage/discharge relations and
surface water and groundwater relationships. Both low-flow and flood
series distributions were defined using the Log-Pearson Type III method.
Additional low-flow data were obtained from seepage runs made on the
Suwannee River during drought periods. Surfacewater quality, sampled
at eight stations, was tested for 14 selected parameters. Comparative
analyses of water quality at the stations were rendered by application
of basic statistical methods, graphical analysis, and a Piper Trilinear

Humid, subtropical climatic conditions prevail in the Upper Suwan-
nee River Basin. The average year-round temperature is 670F. The
warmest temperatures are generally recorded during the summer months
of June through August. At this time maximum temperatures average
near 900F. The coldest temperatures are usually recorded during the
winter months of December and January. Minimum temperatures
average in the mid-forties. Rainfall in the Upper Basin averages 54 in-
ches per year. The highest rainfall rates usually occur in June through
August in association with convectional activity. During the summer
months and early fall, tropical storms and hurricanes can also bring in-
clement weather and heavy precipitation into the area. Rainfall during
the winter, associated with frontal system activity, is usually of a longer
duration and really more uniform than convectional precipitation (Miller,
et al., 1978b). The least amount of rainfall generally occurs in the fall
during October and November. The average evapotranspiration rate
estimated for the area is 42 inches per year (Fisk, 1977).

For the use of those readers who may prefer to use metric units
rather than the customary U.S. units, the conversion factors for terms
used in this report are given here.

Acres 0.4047 Hectares
Acres 4047.0 Square Meters
Cubic Feet/Second 28.3137 Liters/Second
Degrees Fahrenheit 5/9 (F-32) Degrees Centigrade
Feet 0.3048 Meters
Gallon/Minute 3.785 Liters/Minute
Horsepower 1.014 Horsepower (metric)


Square Feet
Square Miles


Square Meters
Square Kilometers




The Upper Suwannee River Basin is located on the eastern margin
of the huge depositional basin that has become known as the Gulf Coast
Geosyncline. According to Murray (1961), this feature may have
originated as early as pre-Cambrian time; but its present form is the result
of tectonic movements associated with the Appalachian and Ouachita
orogenies in late Paleozoic time. Pressler (1947) divided the sediments
on the eastern flank of the Gulf of Mexico sedimentary basin into the
North Florida Province and the South Florida Province by a general line
running from Levy County northeast of Nassau County, Florida. The
North Florida Province is composed predominantly of terrigenous, plastic
sedimentary rocks; and the South Florida Province is dominated by
carbonate sedimentary rocks. Puri and Vernon (1964) recognized these
same two provinces but preferred the names North Gulf Coast Sedimen-
tary Province and Florida Peninsular Sedimentary Province, respectively.
Although the study area is located north of the boundary drawn by
Pressler, the sediments are principally carbonates. Chen (1965) pointed
out that the boundary between these two provinces has shifted
geographically through geologic time. The region of Florida in which the
study area is located is, therefore, considered to be within a transition
zone between the two sedimentary provinces.
The Florida Peninsula has been divided into three district geomor-
phic zones by White (1970). These zones are the Southern or Distal Zone,
the Central or Mid-peninsular Zone, and the Northern or Proximal Zone.
The low-lying, flat lands of the Distal Zone are markedly different from
the undulatory surface of the Central and Northern Zones. Characteristi-
cally, the Central Zone is a series of ridges and valleys which run parallel
to the peninsula coastline. The Northern Zone, in which the Upper
Suwannee River Basin is located, is characterized by a continuous, broad
upland that extends from the northern segment of the peninsula to
western Florida. The major physiographic divisions within the Northeri
Zone are the Northern Highlands and the Gulf Coastal Lowlands.
The four major geologic structural elements within land borderin ]
the Upper Suwannee River Basin are the Peninsular Arch, the Ocaii
Uplift, the Southeast Georgia Embayment, and the Suwannee Strait r
Saddle. The Peninsular Arch is a totally subsurface structural feature i
Florida, and it lies on the southwestern flank of the Peninsular Arch. Th i
Southeast Georgia Embayment is a downwarped area lying to the north 1
and east of the Peninsular Arch. The Suwannee Strait borders the Penir
sular Arch on the north and was an effective barrier to plastic deposition
in both Mesozoic and Cenozioc time.


The stratigraphic units encountered in the study area range in age
from Paleozoic to Recent. The Paleozoic sediments are predominantly
shale and quartzitic sandstones. The Mesozoic sediments are very sandy
and tend to be more calcareous toward the top. Cenozoic units are
dominated by deposits of limestone and dolomite. Virtually all of the
geologic units associated with the Cenozoic and Mesozoic eras are
relatively thin when compared with their equivalents in south Florida.
This is due to the presence of the positive structural features in the area.

The Northern Highlands are the most prominent physiographic
feature in north-central Florida. The physiographic map (Figure 2) shows
that the Northern Highlands almost entirely encompass the study area.
The Northern Highlands are separated from the Coastal Lowlands by
what has been described as the most "persistent topographic break in
the state" by Puri and Vernon (1964). This escarpment is called the Cody
Scarp and extends from the eastern perimeter of Trail Ridge, through
the study area, and across northern Florida into Alabama. Within the
Upper Suwannee River Basin the crest of the scarp approximately
correlates with the 110-foot topographic contour; and its continuity is
broken by the Suwannee, Withlacoochee, and Alapaha rivers.
The Lake City Ridge (Figure 2) is a geomorphic feature associated
with the Northern Highlands. It was recognized by Pirkle (1972) as the
more southerly of two prominent ridges which intersect the Trail Ridge
in southeastern Georgia and northern Florida. Elevations on the Lake City
Ridge vary from 150 to 215 feet and are generally about the same as
the elevations on Trail Ridge. Pirkle described the Lake City Ridge as
extending from Lake City, Florida, to a point six or seven miles west of
Macclenny, Florida, where it turns north to meet Trail Ridge at the St.
Marys River. Knapp (1979) showed an area west of Lake City to have
a lithology, configuration, and topography similar to this easterly ridge.
This area, lying directly east of Live Oak and southwest of White Springs,
is here included as part of the Lake City Ridge.
There are three marine terraces or elevation zones recognized within
the Upper Suwannee River Basin. These are the Wicomico (70' to 100'
Elevation), the Okefenokee (100' to 170' elevation), and the Coharie
(170' to 215' elevation) (Healy, 1975). The Wicomico Terrace extends
i p all of the major river valleys and is part of the Gulf Coastal Lowlands.
he Okefenokee Terrace forms the higher elevations surrounding these
ver valleys, and the Coharie Terrace is represented by the Lake City
The Gulf Coastal Lowlands extend into the southwestern segment
f the study area (Figure 2). The Suwannee, Alapaha, and Withlacoochee
i ver valley lowlands are present in the study area. All of these river valley
I )wlands extend into the Northern Highlands but are still considered part
Sf the Gulf Coastal Lowlands division. The Suwannee River Valley

R 11E

R 17E O


MA DIsoN C~O T18

1 0 3 6 MI. Oak r
0 2 4 6 8 Km. G)

Cody Scarp i3

Figure 2. Physiographic features.


.owlands are larger and more distinctive than the other river valley
lowlands in the study area.
The change in course of the Suwannee River at White Springs from
i north-south to an east-west direction is to a large degree the result
of the stratigraphy and structure of the study area. Above White Springs,
ihe Suwannee River bed is entrenched in the Miocene Hawthorn For-
mation; and downstream from this point the Oligocene Suwannee
Limestone forms the walls and bed of the river channel to Ellaville. The
change in lithology between these two formations is influential in the
course of the Suwannee River.
The lithology of the beds associated with the Hawthorn Formation
and exposed in the river channel varies from a weakly cemented,
argillaceous, phosphatic sandstone to a well-indurated, phosphatic
dolomite with interbedded clayey sands and sandy clays (Appendix A-2).
The more resistant and stratigraphically lower beds of this formation,
which are dolomitized and/or silicified, are most apparent east and north-
east of White Springs where they are influential in turning the river to
the west. The durability of these bends to fluvial processes is exemplified
by the numerous overhanging dolomite ledges and the abundance of
silicified materials along the shoal areas. A relatively thin (less than 8'),
green, clayey sand bed or, less commonly, a calcareous clay bed
separates the dolomitic beds from the top of the Suwannee Limestone.
When the river channel intersects the Suwannee Limestone, it aligns its
course parallel to the major fracture patterns in the study area and
assumes a northwesterly course (Vernon, 1951). Downstream from the
confluence of the Withlacoochee River, the course of the Suwannee River
follows the regional topography and flows in a predominantly southerly
direction to the Gulf of Mexico.


The Peninsular Arch is the dominant subsurface structure in the
Florida Peninsula (Figure 3). Applin (1951) used the name "Peninsular
/ rch" to describe "the anticlinal fold, or arch, which is approximately
275 miles long, trends south-southeastward, and forms the axis of the
F orida Peninsula as far south as the latitude of Lake Okeechobee."
F pplin (1951) concluded that the Peninsular Arch had been a dominant
s ibsurface structure since Paleozoic time and owes its present configura-
t )n to regional movements during the Mesozoic and Cenozoic. The Upper
j wannee River Basin lies west of the crest of the Arch, which is in the
V cinity of Union and Bradford counties, Florida, and is at a depth of 2600
t 3000 feet below sea level (Applin and Applin, 1967). The pre-
. 'esozoic rocks that form the crest of the Arch are described as having
b ,en topographically high during Early Cretaceous time (Puri and Vernon,



r"----------.-,C~ -~-~~"-'~---1
I,. v



10 0 60 100 Mi.
0 50 100 180 Km.

0O C

Figure 3. Major structural features of North Central Florida and
South Georgia.


1964) and were not completely covered by sediments until Late
Cretaceous time.
The term "Ocala Uplift" was first used by O.B. Hopkins in the USGS
press release in 1920. It was documented and described by Vernon
(1951) as "an anticline that developed in Tertiary sediments as a gentle
flexure, approximately 230 miles long, and about 70 miles wide where
exposed in central peninsular Florida." He showed the structure to have
been active from Late Eocene to Early Miocene time. Despite the develop-
ment of this feature along the flanks of the Peninsular Arch, it does not
appear to reflect any structural association with that feature. This
conclusion was reached by Vernon (1951) because wells drilled on the
crest of the Ocala Uplift in eastern Citrus and Levy counties penetrated
the Peninsular Arch well down on its flanks after encountering relatively
thick sequences of Mesozoic strata. Chen (1965), in studying the regional
Paleocene and Eocene stratigraphy of Florida, reported the Ocala Uplift
to have formed in "post-Oligocene or Lower Miocene" time. In later
work, Winston (1976) proposed that the Ocala Uplift was not really an
anticline but had resulted from the anomalous thickening of the Lake
City Formation and the eastward tilting of the Florida Peninsula.
The Southeast Georgia Embayment (Toulmin, 1955), also termed
the Okefenokee Embayment (Pressler, 1947), is a negative feature which
lies to the northeast of the study area (Figure 3). This basin plunges in
an easterly direction beneath southeast Georgia, northeast Florida, and
the adjacent continental shelf. Murray (1961) expanded the area encom-
passed by the embayment and referred to it as the Savannah (Southeast
Georgia) Basin. He felt that this larger feature may have been active as
early as the Paleozoic Era. Herrick and Vorhis (1963) proposed the term
"Atlantic Embayment of Georgia" for a major structural feature in
southeastern Georgia. They thought that the basin originated in Middle
Eocene time and was active intermittently through Middle Miocene time.
Determining when deposition began in this basin appears to be a question
of defining the geographic limits of the embayment. For the area referred
to by Pressler (1947) and Toulmin (1955), deposition was most active
during Paleocene-Eocene time (Chen, 1965) and progressed inter-
riittently through Middle Miocene time.
The Suwannee Strait lies directly adjacent to, and partly within, the
Upper Suwannee River Basin (Figure 3). The term "Suwannee Straits"
kas first used by Dall and Harris (1892) to define an area "which
s aparated the continental border from the Eocene and Miocene Island"
\'here Hawthorn sediments were deposited. Hull (1962) described the
E uwannee Strait as being more than 200 miles long and 20 to 30 miles
\ ide with up to 800 feet of relief developed on top of the Cretaceous
r >cks. The origin of the Strait is quite debatable. Jordan (1954) attributed
i to regional movements at the close of the Cretaceous, causing a
c iannel to be formed along the transition zone between the plastic and
carbonate faces of the Cretaceous. Hull (1962) considered it to be a
r arrow area of nondeposition due to the effects of oceanic currents


similar to the present-day Gulf Stream. Chen (1965) used the tern
"Suwannee Channel" and described it as "the site of relatively thiiu
accumulation of very fine sands, silts, clays, and limestones at leas,
during the time from late Upper Cretaceous to Lower Eocene." He felk
that slower Paleocene-Eocene accumulation of sediment within the
channel rather than differential erosion was responsible for the feature.
Applin and Applin (1967) used the term "Suwannee Saddle" and
designated it as "a subsurface syncline that extends about 200 miles
in a broad arc from southeastern Georgia to Jefferson, Leon, and Wakulla
counties in north-central Florida, bordering the Peninsular Arch on the
north and northwest." They interpreted the feature as an upwarped
barrier during Late Cretaceous time and concluded that widespread
tectonic movements in the Tertiary in the Coastal Plain of Georgia and
the Florida Peninsula resulted in the relative depression of the upwarped
feature due to uplift of the areas north and south.

Table 1 shows the stratigraphic units which exist in the Upper
Suwannee River Basin. The outcropping formations range in age from
Oligocene to Recent. From oldest to youngest they are: the Suwannee
Limestone, the St. Marks Formation, the Hawthorn Formation, and the
undifferrentiated Marine Terrace Deposits. The Eocene and older
stratigraphic units are restricted to the subsurface. Figure 4 is a cross
section showing the shallow stratigraphy of the study area.

Paleozoic Erathem
Within the study area there have been three wells drilled deep
enough to penetrate pre-Mesozoic sediments. Applin (1951) described
and interpreted these wells and referred the lowermost beds to the
Paleozoic Erathem. Well number 1548 in Suwannee County (T2S,R15E,
Sec. 28, Figure 5) encountered a black shale at an elevation of -3333
msl and -3165 msl, respectively. Berdan and Bridge (in Vernon, 1951)
examined these shales and concluded from faunal evidence that the I
were of "Upper Silurian or Lower Devonian" age. In Well 1789 (T1F
R17E, Sec. 22);,Applin (1951) also listed six intrusions of diabase an I
amygdaloidal basalt sills within the black shales. He assigned these intr -
sions to the Triassic Period. Other deep wells bordering the study are i
have revealed the presence of quartzitic sandstones believed to L ;
Ordovician in age.


Table 1. Stratigraphic nomenclature for geologic formations
in the upper Suwannee River Basin.


? Recent
E Pleistocene Unnamed Marine Terrace

Pliocene Undifferentiated Marine Terrace

Miocene Alum Bluff Hawthorn Formation

Tampa St. Marks Formation
Z Oligocene Vicksburg Suwannee Limestone
Crystal River Formation
o co.


Claiborne Avon Park Limestone

Wilcox Lake City Limestone

Paleocene Midway Cedar Keys Formation

Navarro Beds of Navarro Age
Taylor Beds of Taylor Age
Gulf Austin Beds of Austin Age
0 Woodbine- Atkinson Formation
0 Eagleford
() Comanche Unnamed red and variegated sand

Unnamed intrusions of diabase
and amygdalar basalt skills

o c Unnamed micaceous shale
o |
N m
LU Unnamed quartzitic sandstone

150 W wl


0 -











-600 -


-700 -

Fine to Medium Sand

Phosphatic Sand Medium Grained Limestone (Calcarenite)

Calcareous and Dolomitic Clay and Silt Micritic and Coquinoid Limestone

Calcareous Sandstone Higly Recrystallized Dolomitic Limestone

Very Fine Grained Limestone Highly Recrystalized Dolomite

Figure 4. Geologic cross section.

1 0 2 4 6 ILE RS
0 2 4 6 8 KLOMETERS

14vo (MS()














4 600



R if

Well Locations
(Wells with cuttings taken, well data in appendix A-1)
Auger Sample Locations

Figure 5. Stratigraphic data points.

,13E G E R G A
S--R 25 E

A A A f/











Mesozoic Erathem

Cretaceous System
The Paleozoic sediments are overlain unconformably by rocks of
Early Cretaceous age. These sediments have been assigned to the
Comanche Series by Applin (1951). They are described as consisting
predominantly of red and variegated sand that tends to be conglomeratic
at the base. The Comanche Series is overlain by the Upper Cretaceous
Gulf Series. The Gulf series consists of beds that are equivalent to the
Woodbine, Eagle Ford, Austin, Taylor, and Navarro stages of the Gulf
Coast. The basal Woodbine and Eagle ford equivalent beds are sandy,
calcareous, glauconitic, and shaly with a distinct microfauna. The Austin,
Taylor, and Navarro equivalent beds are composed of marine limestones,
dolomites, and chalks.

Cenozoic Erathem

Paleocene Series
The Paleocene Series within the study area unconformably overlies
the Gulf Series and is represented by sediments belonging to the Cedar
Keys Formation. The term "Cedar Keys Formation" was proposed by
Cole (1944) and "designed to cover the rocks encountered in wells in
peninsular and northern Florida from the first appearance of the Borelis
fauna to the top of the Upper Cretaceous." Cole also determined the
Cedar Keys Formation to be the stratigraphic equivalent of the Midway
Formation of the Gulf Coast area. Applin and Applin (1944) described
this formation as a "gray and cream-colored to white limestone,
commonly having a distinctive spotted appearance." Within the study
area, the Cedar Keys Formation occurs as a slightly gypsiferous dolomite
containing the foraminifer Borelis.

Eocene Series
The Oldsmar Limestone overlies the Cedar Keys Formation within
the Upper Suwannee River Basin. The term "Oldsmar Limestone" vwas
originally used by Applin and Applin (1944) to denote the nonclastic ro :ks
of Early Eocene age in Peninsular and northern Florida. This unit is mar: ed
at the top by abundant specimens of the foraminifer Helicostegina gyr. !is.
Chen (1965) recognized a conformable relationship between this i nit
and the overlying beds. Within the study area, the Oldsmar Limeste ne
is essentially composed of dolomite and limestone with evapori es
(gypsum and anhydrite) and glauconite being minor accessory miner Is.
The Lake City Limestone overlies the Oldsmar Limestone through ut
the study area. Applin and Applin (1944) first used the term "Lake ( ty
Limestone" for rocks of early Middle Eocene age and described this i tit
as a dark brown and chalky limestone in northern and peninsular Flori !a.


Th e Applins established the top of the Lake City as the highest appear-
ance of the foraminifer Dictyoconus americanus. Within the study area,
the Lake City Limestone is predominantly a gray-brown, dense,
mcrocrystalline dolomite with occasional thin beds of limestone, chert,
and carbonaceous material. Commonly, this unit is impregnated with
gypsum and anhydrite.
It is difficult to lithologically differentiate this unit from the underlying
Oldsmar Limestone in this area of Florida. The lithologies of the two are
markedly similar and differences in microfauna are the major criteria for
formation separations. The Oldsmar Limestone, Lake City Limestone,
and possibly the Avon Park Limestone in this area could easily be referred
to as one formation and divided into several biostratigraphic zones.
The Avon Park Limestone overlies the Lake City Limestone through-
out the study area. The term "Avon Park Limestone" was proposed by
Applin and Applin (1944) for sediments of late Middle Eocene age in
Florida. Vernon (1951) described three different lithologies within this
unit where it crops out in Citrus and Levy counties, Florida. In general,
these lithologies are a very fossiliferous limestone, a fossiliferous, peat-
flecked limestone, and a very crystalline dolomite. The Avon Park
Limestone within the study area occurs predominantly as a dolomite with
numerous molds and casts of foraminifera, especially Dictyoconus
The Ocala Group overlies the Avon Park Limestone throughout the
study area. The term "Ocala Limestone" was first used by Dall and Harris
(1892). This unit is named after the city of Ocala, Marion County, Florida,
where it has been quarried for many years. Cooke (1915) established
the Ocala Limestone as Eocene in age and proved that its fauna is essen-
tially identical to that of the Jackson Stage. Applin and Applin (1944)
showed that the Ocala Limestone could be divided into an upper and
a lower member. Puri (1953) followed Vernon (1951) in recognizing three
distinct units that he believed were present within the strata of the
"Ocala Limestone." He proposed for his units the names Crystal River
Formation, Williston Formation, and Inglis Formation "in descending
order and depth" and suggested that the new formations should be
included in the Ocala Group. This usage is followed in this report.
The Ocala Group does not crop out within the Upper Suwannee River
Ba ,in. It is, however, ubiquitous in the subsurface, being overlain
un :onformably by the Suwannee Limestone or Hawthorn Formation and
un lerlain unconformably by the Avon Park Limestone. The structural top
of the Ocala Group is depicted in Figure 6. Lithologically, in this area
thi Ocala can be separated into two formations. The upper unit (Crystal
Ri\ er Formation) is a very pale orange tb very light gray, moderately
inc urated, biogenic, and very micritic limestone containing many larger
foi .minifera. The lower unit-Williston Formation-is a very pale orange
to tery light gray, moderately indurated, biogenic, and medium-grained
lir rastone (calcarenite) containing many smaller foraminifera especially
Ar 'phistegina pinarensis cosdeni). The boundary between these two
foi-nations is conformable and gradational.

Fiaure 6. Structural top of Ocala Group.

0 LOR 11 C-0 R 13 E G E 0 R Gj I
-12 -150 R 17 E -200
-60 ennngR 0
irHAMI H A M I L T 0 N C 0T

a A
r T
M A 01 6 0N C 0 ~ -175


%11- O -


Oligocene Series
The term "Suwannee Limestone" was established by Cooke and
Mansfield (1936) for limestone exposures along the Suwannee River
from White Springs to the confluence with the Withlacoochee River
containing the echinoid Rhyncholampas (cassidulus) gouldii. In the period
before 1936 the characteristic Suwannee Limestone beds were placed
in various other formations. Matson and Clapp (1909) placed them in
the Hawthorn Formation; Mossom (1926) referred them to the Glendon
Formation; and Cooke and Mossom (1929) put them in the Tampa
Limestone. Cooke (1945) described the lithology and fauna of the
Suwannee Limestone regionally. Puri and Vernon (1964) summarized
various other authors, presented several measured sections, and listed
associated fossils. Colton (1978) studied the lithostratigraphy and
depositonal history of this formation in detail in Hamilton County.
The Suwannee Limestone crops out along the Withlacoochee River
from near the Florida and Georgia border to the confluence with the
Suwannee River and along the Suwannee River from White Springs to
the confluence with the Withlacoochee River. The structural top of the
Suwannee Limestone is depicted in Figure 7. The Suwannee is normally
found as a very pale orange, moderately indurated, very porous
calcarenite with numerous foraminifera, mollusks, and echinoids present.
It is unconformably overlain by either the St. Marks or Hawthorn forma-
tions. Colton (1978) recognized another major lithology within the
Suwannee Limestone and described it as "a dense, hard resonant
limestone composed of foraminiferal tests completely embedded in dense
crystalline calcite." Other minor lithologies associated with this forma-
tion include silicified limestone, dolomite, and lithographic limestone. The
Suwannee Limestone can be differentiated from the overlying St. Marks
Formation by its lack of sand, more granular texture, and characteristic
faunal content (Appendix A-3). The underlying Crystal River Formation
is much more micritic and has a distinctive fauna.

Miocene Series
The sediments now assigned to the Tampa Stage (Lower Miocene)
ha.,e been subdivided and redefined may times. Finch (1923) referred
to 1he limestone at St. Marks in his description of mollusks from Wakulla
Co nty, Florida. The name "Tampa Formation" was applied to the
lirr stone outcrops near Ballast Point in Hillsborough County, Florida,
by L.C. Johnson in 1888. Dall and Harris (1892) included the Tampa,
Ch pola, and Alum Bluff beds in the Tampa Group. Matson and Clapp
(11 09) put the Tampa Formation in the base of the Apalachicola-Group
an i restricted it to south Florida. Cooke and Mossom (1929) changed
the name "Tampa Formation" to "Tampa Limestone" and redefined it
to include the Chattahoochee Formation. Vernon (1942) used the term
"T impa Formation" to include "all sediments lying above the Suwannee
Liriestone and below the Alum Bluff Group." Puri (1954) erected the


z o-

I- .-* I-
0 c




N 0
l e
,. o ,


O J o 00 ? 4 0 N U

t Q
cw oo_ *,H w "

o o a
-J 0

'L i.

NC r -


T 3mpa Stage in his study on the Miocene of the Florida Panhandle and
ir cluded in it "all Miocene sediments lying between the Oligocene Series
aid the Alum Bluff Stage." Within the Tampa Stage he recognized two
d fferent lithofacies-an updip, silty, and clayey lithology (Chattahoochee
Ficies) and a downdip, calcareous lithology (St. Marks Facies). Puri and
Vernon (1964) described the Chattahoochee and St. Marks formations
as comprising the Tampa Stage (Lower Miocene). They established a
type locality for the St. Marks Formation in Wakulla County, Florida. Yon
(1966) adhered to the nomenclature presented by Puri and Vernon and
described the St. Marks Formation in Jefferson County as "a white to
very pale orange, finely crystalline, sandy, silty, clayey limestone
(calcilutite)." Within the study area, the St. Marks Formation is a very
pale orange, sandy, silty, occasionally fossiliferous, and micritic
limestone. It occurs infrequently along the northern Withlacoochee River
and in deep sinkholes in western Hamilton county. This formation is thin,
discontinuous, and only occurs as erosional remnants east of the Alapaha
The Hawthorn Formation is named after the town of Hawthorne
located in Alachua County, Florida. Dall and Harris (1892) were the first
authors to use the term "Hawthorne Beds" when referring to phosphatic
limestone they saw being quarried and ground for fertilizer near the town
of Hawthorne, Florida. Dall also cited some measured geologic sections
by L.C. Johnson. Matson and Clapp (1909) designated these beds the
Hawthorne Formation. They described the formation as consisting of
clays, sands, and phosphatic limestone and lying stratigraphically be-
tween the limestones of the Vicksburg Group and the Alum Bluff
Formation. Vaughn and Cooke (1914) showed that the Hawthorn
Formation is almost synonymous with the Alum Bluff Formation as
defined by Matson and Clapp (1909) and recommended that the name
"Hawthorn" be discarded. Gardner (1926) raised the Alum Bluff deposits
to the rank of group including the Chipola Formation (at base), the Oak
Grove Sand, and the Shoal River Formation (at top). Cooke and Mossom
(1929) restored the name "Hawthorn Formation" by fitting it into the
Alum Bluff Group. They referred to the Hawthorn Formation as being
different from other formations in the group, containing some fossils that
ar of Chipola Age, and excluding the "Cassidulus-bearing" limestone
(S jwannee Limestone) which is older. Cooke (1945) described outcrops
of the Hawthorn Formation along the Suwannee River and in Columbia
C< unty. Puri and Vernon (1964) erected the Alum Bluff state and included
th Hawthorn Formation within it. They also examined Hawthorn out-
cr Ips in the Upper Suwannee River Basin and concluded that this unit
in :his area presented the most diversified lithofacies of the Hawthorn.
MI ler (1978a) in his description of geologic and geophysical logs from
tF ? Osceola National Forest area identified five lithologic units within
th i Hawthorn (Table 2).
The Hawthorn Formation is exposed continually in the banks of the
S wannee River from the Florida-Georgia border to White Springs and


Table 2. Relationship of lithologic and geologic units
in Osceola National Forest (from Miller, 1978a).

Unit Age (feet) Lithology
Unnamed Post- 6-54 Medium-grained sand and blue-gray
Miocene sandy clay. Local peat layers.
A 15-102 Brown phosphate sand, yellow-brown
to blue-gray clay, gray phosphatic
shell limestone. Limestone more pro-
c minent in western part of forest.
B ., 13-70 Green to greenish-gray massive clay.
co Often fractured. Black clay prominent.
C E- ( 13-58 Green to greenish-gray, fine- to
o -
LL ) medium-grained sand. Contains clay
c o and limestone to east of forest.
D 5-43 Complexly interbedded shell
limestone, clay, clayey sand, and
co fine-grained sandstone.
E 14-73 Brown sandstone, tan to dark-brown
limestone, dolomite, and argillaceous
limestone. Fossiliferous, well
Ocala' 102+ White calcarenite at top, containing
Lime- Eocene some green clay. Gray hard fractured
stone limestone below. Penetrated 102
'The Suwannee Limestone of Oligocene age, which is part of the Floridan Aquifer in places,
was not found in the Osceola National Forest.

intermittently from White Springs to the confluence of the Alapaha River
(Figure 8). The top of the Hawthorn Formation normally occurs as
phosphatic clayey sands and pale blue-green, phosphatic clays. The unit
as a whole is characteristically phosphatic, dolomitic, calcareous, clayey,
and heterogenous throughout. The lower section is dominated by sandy,
phosphatic dolomites and limestones. The St. Marks Formation and
Suwannee Limestone underlie the Hawthorn Formation in the study arca.
The absence of phosphorite and lower percentages of quartz sand in tie
St. Marks Formation and Suwannee Limestone are the major distinctic is
between them and the Hawthorn Formation. East of a line drawn from
Live Oak, Florida, to Jasper, Florida, and within the Upper Suwann .e
River Basin, the top of Hawthorn Formation gently slopes down to t ie
northeast (Figure 9). The structural highs near Lake City, Florida, a d
Township 3 South, Range 15 East are due to uneroded, thicker accumu a-
tions of the Hawthorn in these area. In parts of the study area, tie
Hawthorn Formation is either absent or has been greatly modified )Y
post-depositional erosion.


ii I W-1 GE 0 1C- IA


::::SAND o

Figure 8. Location and lithology of surface



10 MI.

10 Km.

-r_--... ..r E W-13
,' ,I .. .." '


Rll 1 12R 1580 3 G E 0 R G

innings HAMIL 0N CO ,

HMI N A \ A A A A N 2

a We Locato* n

Bl \A \ g

S10 3 6 Mi
024 8 Km. UW NN

A Auger Samples

76 *" Contour on the Upper Surface of 125 12 100
Hawthorn Formation n Feet above MSL
Contour Interval 25 Feet
E9 Hawthorn Formation Absent

rlPCIIIrr~s ~L~a3 --g~r II

rslq sv aaY U~--I~8~r~s~sited"1Qa


The name "Alachua Clays" was first used by Dall and Harris (1892)
ir a reported memorandum they submitted to the Director of the USGS
ir 1885. They described the clays as being "of a bluish or grayish color
and extremely tenacious" and containing a mammalian fauna. The
MViocene Alachua Formation was reported by Cooke (1945) to exist in
Hamilton County west of the Alapaha River, although no details were
available. Puri and Vernon (1964) described this formation as being
terrestrial and, in part, possibly lacustrine and fluviatile. Lithologically,
it is quite diverse, being a mixture of interbedded sand, clayey sand, and
sandy clay. Within the Upper Suwannee River Basin it is not possible
to lithologically differentiate the Alachua Formation from the Hawthorn
Formation and the Undifferentiated Marine Terrace Deposits, either in
outcrop or in the subsurface. In observations of outcrops within the study
area, a few localities were found where mammalian fauna was preserved
in clays and sandy clays. However, the occurrence of these deposits
are infrequent and lateral correlation between them is not apparent. The
Alachua Formation is not recognized as a geologic formation in this

Plio-Pleistocene Series
The term "Undifferentiated Marine Terrace Deposits" is here used
for the plastic materials which lie above the Hawthorn Formation. These
deposits are normally fine-to medium-grained quartz sand with minor
amounts of organic material, clays, and heavy minerals. They are virtually
ubiquitous in the Upper Suwannee River Basin and are only absent where
they have been eroded by streams or rivers. These terrace deposits owe
their origin to Plio-Pleistocene eustatic sea level fluctuation. Figure 10
depicts the total thickness of Hawthorn sediments plus these undiffer-
entiated sediments.

" -------- O _1 R15E i1 7




T3 S

Well Locations
A Auger Samples
75of.. Line of Equal Thickness in Feet 10 1

ure 10. sopach of combined Hawthorn Formation and PoPeistocee deposits.
Figure 10. isopach of combined Hawthorn Formation and plio.Pleistocene deposits.



There are three aquifer systems within the Upper Suwannee River
Basin (Figure 11). A perched, surficial (water table) aquifer mantles the
Northern Highlands. Areas where the surficial aquifer exist are usually
underlain by a secondary artesian (Hawthorn) aquifer that is wholly con-
fined by low permeability units within the Hawthorn Formation. The
Floridan Aquifer displays two distinct characteristics. It is artesian where
it underlies the secondary artesian aquifer; it is nonarteasian in areas
where the Hawthorn Formation is thin or nonexistent.
The unconfined surficial aquifer, consisting of Miocene and younger
sands, maintains the highest water levels relative to mean sea level. The
secondary artesian aquifer, comprised of sands and carbonates of the
Miocene Hawthorn Formation, has water levels at altitudes between
those of the surficial aquifer and the Floridan Aquifer. The potentiometric
surface of the artesian portion of the Floridan Aquifer is higher than the
potentiometric surface where the Floridan is unconfined; therefore, water
within the Floridan Aquifer flows from the artesian to the nonartesian
portion. The portion of the Floridan Aquifer that contains potable water
consists of carbonates that range from early Miocene to middle Eocene
in age.
These aquifer systems can be differentiated by water chemistry as
well as by stratigraphic position, lithology, and hydraulic heads. Ground-
water samples from the study area were analyzed for the following
variables; pH, specific conductance, alkalinity, chloride, flouride, sulfate,
orthophosphate, nitrate, calcium, magnesium, sodium, and potassium
(Appendix B-2). These variables tend to be correlated; that is, an increase
or decrease in one variable may be accompanied by a predictable change
ir another variable. The mutual variablility or covariance of a pair of pro-
pwrties is the joint variation of two variables about their common mean.
Ir order to estimate the degree of interrelation between variables, the
correlation coefficient is used. Correlation is the ratio of the covariance
o two variables to the product of their standard deviations (Davis, 1973).
P !arson Product Moment correlation coefficients of the variables sampled
ft r this study are shown in Appendix B-3. The correlation coefficient
i, used as a similarity measure. Two variables are connected that have
ti e mutually highest correlations with each other.
A cluster diagram constructed from the mutually highest correla-
t in coefficients is shown in Figure 12. This diagram shows the relation-
s ip among variables. A + indicates a strong correlation between the
t to variables (r is ) + 0.3). A "(+)" indicates a weak correlation between
t e two variables (r is between + 0.135 and + 0.03). For a sample size
c 370, a correlation coefficient of >0.135 is significant (Rohlf and Sokol,
1 '69). The three cluster relations in Figure 12 represent chemical pro-

HYDROGEOLOGY confined (artesian)
Floridan Aquifer
SCLAY unconfined (non-artesian) %9 O
Floridan Aquifer

UNIT are members A .'..
within HAWTHORN H| k

Figure 11. General hydrogeology.



cesses that reflect water in contact with different lithologies. Each
lithology is associated with a different hydrogeologic horizon.
The variables in Cluster 1 are associated with the dissolution of
calcium and magnesium carbonates. This is the lithology that comprises
the Floridan Aquifer. Therefore, Floridan waters are typically character-
ized by higher relative values for calcium, magnesium, alkalinity, pH, and
specific conductance, which reflect the amount of bicarbonate in the
water. Sulfate values are relatively higher in the Floridan Aquifer due to
oxidation of sulfides or dissolution of evaporites in ground water at depth.

pH SC Alk SO4 Ca Mg C1 Na K N03 F 0-P04

+ Strong Correlation (r > .300)
(+) Weak Correlation (r = .135 to .300)
Significance Level for 370 Samples = 0.135 (Rohlf and Sokol, 1969)

Figure 12. Cluster analysis of water quality parameters.
The variables in Cluster 2 are associated with marine aerosols. The
Dominant lithology containing surficial aquifer water is sand that does
ot readily react with water. The water in the surficial aquifer is essen-
ally rainwater that is relatively higher in sodium, chloride, and potassium
'ian water from the lower aquifers. The higher relative values for nitrate
re man-induced.


The variables in Cluster 3 are associated with the dissolution of
fluorapatite. The Hawthorn Formation contains abundant flourapatite.
The secondary artesian aquifer is entirely within the Hawthorn and is
characterized by water that has higher relative concentrations for
orthophosphate and fluoride than the other aquifers.
An aquifer test at Occidential Chemical Company in Hamilton County
indicates that the cofficient of transmissivity is about 190,000 ft2/day;
and the coefficient of storage is about 0.001 for the confined artesian
portion of the Floridan Aquifer.

Table 3. Water Use in the Suwannee River
Above the Withlacoochee and the Alapaha Subbasins in Florida.

Pumpage (MGD) (MGD)
Ground Surface
Water Water
Public Supply 2.61 0 0.56
Industrial 28.81 0 4.40
Rural (Domestic) 0.70 0 0.26
Rural (Livestock) 0.22 0.15 0.28
Irrigation (Average) 1.62 0.29 1.88
TOTAL 33.96 0.44 7.38

Within the study area, Lake City, White Springs, Jasper, Jennings,
and Wellborn have public supply wells. Total industrial use is accounted
for by Occidental Chemical Company's phosphate mine and chemical
plant in Hamilton County. Irrigation use is seasonal, but in Table 3
irrigation is averaged daily over the entire year. Most irrigation takes place
during the spring, and a maximum 24.5 million gallons per day (mgd) is
used for this purpose during the peak irrigation period.


Configuration and Extent
An unconfined, surficial aquifer (also referred to as the water table
aquifer) exists in the Upper Suwannee Basin (Figure 13). This aquifei
consists of Miocene and younger sands and clayey sands that blanket
the area and range in thickness from 20 feet to 150 feet. In the Osceolz
National Forest in Columbia County, Miller, et al. (1978b) divided the
Hawthorn Formation into five mappable lithologic units that he assigned
informal letter designations (Table 2). The massive clays of Member E
retard or restrict downward percolation and are the base of the surficia

Figure 13. Extent of surficial aquifer.





aquifer throughout the Upper Suwannee Basin. Member B is the same
unit referred to as Bed A in strata of the Alapaha River Basin (Ceryak,
1977). Member A (Miller, et al., 1978b) of the Hawthorn is entirely within
the surficial aquifer as are the overlying Pliocene, Pleistocene, and Re-
cent sands. The areal extent of the surficial aquifer coincides with the
elevation of two prominent ancient marine terraces within the Northern
Highlands. The Okefenokee Terrace exists between elevations of 100
to 170 feet. Portions of Suwannee and Columbia counties also display
remnants of the Coharie Terrace at elevations between 170 to 215 feet.

Water Level Relationships and Fluctuations
Water levels within the surficial aquifer are at or near land surface
and often coincide with surfacewater levels observed in swamps, lakes,
and ponds. The water table is a subdued replica of the topography and
ranges in altitude from about 100 to 200 feet above msl. The surficial
aquifer is recharged directly by rainfall that migrates vertically downward
to the water table. Mean annual rainfall in the study area is 54 inches
per year.
Water level fluctuations in the surficial aquifer are in direct response
to the amount of rainfall. Rainfall events cause sharp rises in surficial
aquifer levels, while lack of precipitation causes a gradual decline. Nor-
mal annual fluctuation is a few feet as shown in hydrographs of wells
completed into this aquifer (Figure 14).
0 -. .- i7 141
1 j 140
140 Lu
< 2 \ 139
aC 3 --,138 w

0 '
2 P

1976 1977

Figure 14. Hydrographs of wells that tap the surficial aquifer in
Osceola National Forest.



Of the 54 inches of available rainfall per year, approximately 42
inches per year is lost to evaportranspiration (ET) (Fisk, 1977). Discharge
from the surficial aquifer is mostly downward to the underlying aquifers
and is greatest where Hawthorn Member B is breached, discontinuous,
or permeable. There is also lateral discharge along the Cody Scarp and
into topographically low areas-lakes, swamps, and streams. A minimal
amount of water from the surficial aquifer is consumed by rural domestic

Aquifer Properties
In western Hamilton County, the average hydraulic conductance
reported for clayey sands of the water table aquifer (Reynolds, Smith,
and Hills, 1974) was 3.0 x 10-4 ft/min. An aquifer test on the water table
aquifer at the Swift Creek Chemical Complex site in Hamilton County
yielded a storage coefficient of 7.5 x 10-4 and a transmissivity of ap-
proximately 500 ft2/day (U.S. EPA, 1978).

Groundwater Development
Most shallow wells completed into the surficial aquifer are driven
or jetted; a few are dug.
Shallow wells usually consist of one 20-foot section of 1 1/2-inch
or 2-inch diameter pipe. Well screens are not commonly used. A typical
well has a 1/2 to 1 horsepower (hp) jet pump and yields between 4 and
10 gallons per minute (gpm).

Water Chemistry
Surficial aquifer water is characterized by high relative values for
sodium, chloride, potassium, and nitrate. These parameters are strongly
correlated in Cluster 2 in Figure 12. Figure 15 shows the range of values
for each aquifer water type. The ranges extend two standard deviations
from the mean, which accounts for 95% of the variability of the values.
The purpose is to show, along with trilinear and cluster diagrams, distinct
differences in parameter values that define the water types. Figure 15,
ike Figure 12, reveals the relatively high values for the constituents
characteristicc of surficial aquifer water.
The relatively high sodium and chloride values are apparently de-
ived from precipitation of marine aerosols (ocean-derived moisture)
Ceryak, 1977). This is especially true in the summer in peninsular Florida
!vhen ocean-derived moisture accumulates daily as afternoon thunder-
;howers. The CI:Na ratio in seawater is 1.8:1 and, similarly, averages
2:1 in the 61 surficial aquifer water samples that were analyzed. Sodium
s the most abundant cation in seawater, while chloride is the most
abundant anion. Potassium is a very soluble cation found in water and
easily recombines with clay minerals. Figure 15 shows the effect of clays
n the secondary artesian aquifer on potassium correlation, but this ion



H PH units
4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10
C. mlcromhos-cm
id. ON I I_ _
0 50 100 150 200 250 300 350 400 450 500

lk 1= Img/I1
0 40 80 120 180 200 240 280 320 360 400

S17 I I mgl

3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

F 2 .3 .5 .8 mgI
0 1 .2 .3 .4 .5 .6 .7 .8 .9

S4 "n I I
0 3 6 9 12 15 18 21 24 27 30 33 38 39 42 45 48 51 54 57 60 63 66 69 72 75

O-PO4 7.*1i I I
0 .09 .18 .27 .38 .45 .54 .63 .72 .91 1.0 1.09 1.18 1.27 1.38 1.45 1.54 1.63
NO l ,,,mg/I

0 1 2 3 4 5 6 7 8 9 10

Ca 7 "W I l' I"" M "I"o" wwwn""ml'" mp
0 10 20 30 40 50 80 70 80 90 100

WMg W *...*.*II I I' m
0 3 8 9 12 15 18 21 24 27 3"

Na s l I 1 11111
0 1 2 3 4 5 8 7 8 9 10 11 12 13 14 15 18 17 18 19 20 21 22 23 24 2

K ,, mg/i
0 1 2 3 4 5 6 7 81
Surficial Aquifer (61 Samples)
Secondary Artesian Aquifer (7 Samples)
Floridan (Non-Artesian) Aquifer ilaRmammaseummi n u (43 Samples)
Floridan (Artesian) Aquifer (23 Samples)
Mean (Example) I
(This Data Represents 2 Standard Deviations on Each Side of Mean)

Figure 15. Means and ranges of parameter values.




_ 1 I


is also present in relatively high values in the surficial aquifer where clays
are not as abundant. High potassium concentrations in the surficial
aquifer are the probable result of marine aerosols.
High nitrate concentrations in the surficial aquifer appear to be man-
induced. Natural nitrate values can be as high as 5 milligrams per liter
(mg/I) but are often less than 1 mg/l (Hem, 1959). Factors that contribute
to high nitrate values in the surficial aquifer are barnyard animal excre-
ment, chicken and hog barns, chemical fertilizers, septic tanks,
outhouses, and, to a lesser degree, plants that fix nitrate-nitrogen in the
soil. These factors are all common in a predominantly rural area such
as that where the shallow aquifer occurs.
Contrasting these high values, pH, specific conductance, alkalinity,
calcium, and magnesium exhibit relatively low values when compared
with water from the secondary artesian and Floridan Aquifers (Figure
15). Once the cation-anion balance of the variables was determined (Fred
Lawrence, SRWMD, Live Oak, FL, unpublished computer program,
1978), the results were plotted on a Piper Trilinear Diagram (Figure 16).
This is a useful graphical 'method to show sources of, and chemical rela-
tionships between, different groundwater types in the study area. The
trilinear plots help to further distinguish the basin's aquifer types. Piper
Trilinear Diagrams treat ground water as though it contains three cation
constituents (Mg, Na + K, Ca) and three anion constituents (CI, SO4, CO3
+ HCO). Figure 16 shows the distinction between surficial aquifer water
and the deeper aquifer water types on a trilinear diagram. Surficial water
contains a high relative percentage of sodium and potassium cations and
a low relative percentage of calcium cations. The anion balance reveals
relatively high values for chloride and low values for carbonate plus
bicarbonate. The resultant plot on the diamond-shaped field classifies
surficial water as a type where strong acids exceed weak acids compared
to the remaining water types that fall in the category of carbonate hard-
ness "secondary alkalinity", where chemical properties of the water are
dominated by alkaline earths and weak acids (Walton, 1970).
Chapter 17-3 of the Rules of the Department of Enviromental Regula-
Jion of the State of Florida lists water quality standards for Class I-B
'aters (Florida Administrative Code, 1977), potable and agricultural
vater supplies, and storage (ground water). Of the parameters sampled
or this study, fluoride and nitrate have criteria standards. Fluoride shall
lot exceed 1.5 mg/I, and nitrate shall not exceed 10 mg/l. Secondary
standards for chlorides and sulfates limit their concentration to 250 mg/l.
contaminatedd wells in the surficial aquifer display nitrate values as high
's 24?6 mg/l. Values of 114.1 mg/I of chlorides, 89.1 mg/l of sodium,
ind 14.32 mg/I of potassium have been reported. Standards have not
,een set for sodium and potassium, but these values are high when
comparedd to the mean for surficial aquifer waters and are obviously the
esult of point source pollution to the aquifer. High values for the above
>arameters result in specific conductances as high as 600 micromhos
umhos/cm), whereas the mean is 70 umhos/cm and the standard
deviation is 35.8.



Floridan (Non-Artesian) Aquifer
Floridan (Artesian) Aquifer
I Secondary Artesian Aquifer
Surficial Aquifer
- Surficial Aquifer
Secondary Concentration


Figure 16. Piper trilinear diagram-ground water.




Configuration and Extent
The secondary artesian aquifer system underlies most of the Nor-
thern Highlands (elevations higher than 110 feet msl) in the study area.
Where the surficial aquifer exists (Figure 13), the secondary artesian
aquifer usually underlies it. The secondary artesian aquifer system is com-
prised of phosphatic sands, clays, and carbonates (Members C, D, and
E) of the middle Miocene Hawthorn Formation. Permeable beds within
the aquifer system vary in depth and thickness throughout its extent.
Water-bearing Hawthorn sediments in the study area range from around
80 feet to 234 feet in thickness; the entire unit thickens considerably
from the west to the northeast. The massive clays of Member B act as
the upper confining bed for the secondary artesian aquifer (Table 4).
Beneath Osceola National Forest, the E member contains well-indurated
sandstone and dolomitized limestone that acts as a very tight
semipermeable unit and forms the lower confining bed for the secondary
aquifer system and the upper confining bed for the Floridan Aquifer.
Six sets of observation wells penetrate the secondary aquifer system
in eastern Hamilton County at OXY's Suwannee River Mine (U.S. EPA,
1978). The A and B Hawthorn members are definable, but the lower
Hawthorn section has not been differentiated into lithologic zones. As
the Hawthorn thins to the west, the depositional environment changes
from marine to deltaic. The lower section becomes a conglomeration of
sediment types, and, therefore, is difficult to differentiate into lithologic
zones. No single lower confining bed for the secondary aquifer system
has been described in this area, but a thin sand below Member B is
lithologically similar to Member C in the Osceola National Forest. Varia-
tions in lithology in the lower parts of the Hawthorn create variations
in permeability. For the most part, the basal Hawthorn in Hamilton County
can be considered a confining bed separating local permeable Hawthorn
beds from the underlying Floridan Aquifer.

Water Level Relationships and Fluctuations
Water levels in the secondary artesian aquifers are lower in altitude
t ian surficial aquifer levels throughout the study area. In Osceola National
Forest, in two wells completed into the Hawthorn C member, the water
l;ovels (approximately 100' above msl) lie 40 feet below surficial aquifer
levels. Secondary artesian aquifer water levels at the Suwannee River
line (approximately 60' to 75' above msl) are also intermediate be-
t veen surficial aquifer and Floridan Aquifer water levels but are lower
ii altitude than in Osceola National Forest. These water levels from wells
r penetrating permeable fine sands below Member B lie 50 to 60 feet below
t ie water table and 10 to 20 feet above Floridan water levels. The smaller
[ sad difference between the secondary and Floridan Aquifers in the OXY
vells is probably due to a greater amount of hydraulic connection be-

Table 4. Generalized description of hydrogeologic units in Osceola National Forest
(Modified from Miller, et al., 1978b).
Water unconfined. Readily absorbs and Post- 6-54 Medium-grained sand and blue-
stores precipitation until water table rises to Unnamed Miocene gray, sandy clay. Local peat
Surficial land surface. Principal source of baseflow to layers.
Aquifer streams draining forest. Uppermost member A 15-102 Brown phosphatic sand, yellow-
of Hawthorn Formation is hydraulically con- brown to blue-gray clay, gray
tinuous with surficial deposits and forms phosphatic shell limestone. Lime-
lower part of surficial aquifer. stone more prominent in western
___ _part of forest.
Because of comparatively low permeability, B 13-70 Green to greenish-gray massive
most of unit acts to retard the downward o clay. Often fractured. black clay
Hawthorn movement of waterfrom the surficial aquifer prominent.
confining to the Floridan Aquifer. Member C yields C 13-58 Green to greenish-gray, fine- to
unit small quantities of water under confined u. medium-grained sand. Contains
(Secondary conditions. Basal limestone beds are not E clay and limestone to east of
Artesian considered part of the Floridan Aquifer in Forest
Aquifer) Forest. D | 5-43 Complexly interbedded shell lime-
I stone, clay, clayey sand, and fine-
grained sandstone.
E 14-73 Brown sandstone, tan to dark-
brown limestone, dolomite, and
argillaceous limestone.
________Fossiliderous, well indurated.
Floridan Yields large quantities of water under Ocala' Eocene 102 + White calcarenite at top containing
Aquifer confined conditions everywhere under Lime- some green clay. Gray, hard
Osceola National Forest. fractured limestone below. pene-
_______ treatedd 102 feet.
*Thp ~Awnnpc 1irn mitnn o-f O inr)ene age, which is part of the Floridan Aquifer in places, was not found in the Osceola National Forest.


tween the two units there than exists in the Osceola National Forest.
The E member at OXY is thinner and probably more permeable than to
the east. High rates of pumping from the Floridan Aquifer by OXY (28.8
mgd) may also contribute to secondary aquifer drawdown in the area.
Figure 17 compares secondary aquifer potentiometric surface fluct-
uations with Floridan fluctuations in Osceola National Forest wells. The
pattern of fluctuation is similar, but the range of fluctuation in the
secondary aquifer well is one-third the range of the Floridan Aquifer.
Secondary aquifer fluctuations respond to the same changes in storage
that affect the Floridan Aquifer, but the lesser degree.
Feet Above
Mean Sea Level
Artealan us ""'
Aquifer 100



Aquifer 58 U3UIA Uses *


(Modified from Miller).
50 JI JI1 A 1 S-1-0 1'N_ I 1 F IM

Figure 17. Relationship of secondary artesian water levels to Floridan
Aquifer water levels in Osceola National Forest
(Modified from Miller).
In the OXY area, secondary aquifer water levels fluctuate as much
as, or more than, Floridan Aquifer water levels (Figure 18). The basal
Hawthorn confining beds (E member ) apparently are more permeable
at OXY than in Osceola National Forest, accounting for lower secondary
head pressures and a more direct correlation with Floridan Aquifer
ootentiometric surface fluctuations.
The secondary aquifer system is recharged from the overlying
;urficial aquifer wherever Member B is discontinous and leaky. Due to
lack of data, it is difficult to pinpoint exact locations of recharge to the
secondary aquifer. The secondary aquifer discharges vertically
downward to the Floridan Aquifer where confining beds separating the
two are breached through karst activity or are permeable. Some
discharge occurs laterally along the Cody Scarp and anywhere streams
have cut through the upper confining bed (Member B).


Water Level in Feet
Above Mean Sea Level
80 I r' r-r I I

70 '- --
-011502005 -

-011501001 -011502018


501 -,

40 .----
5 10 15 20 25 5 10 15 20 25 5 10 15 20 25 5 10 15 20 25 5 10 15 20 25
-011502009 SRWMD Well Site Identification Number
Secondary Artesian Wells
Floridan Artesian Wells

Figure 18. Relationship of secondary artesian water levels to Florid& n
Aquifer water levels at Occidental Chemical Company.


Aquifer Properties
In 1977 the USGS conducted an aquifer test on the C member of
the Hawthorn in Osceola National Forest. The unit was pumped at 3.2
gpm for 336 hours. Effects of pumping were felt in the C and D members
of the Hawthorn. Analysis of the data by the Hantush Method resulted
in a low transmissivitv of 15 ft2/day and a storage coefficient of 0.00012
(1.2x10-4) (Miller, et al., 1978b).

Groundwater Development
Wells tapping the secondary aquifer system are not common in the
Upper Suwannee River Basin. Where the secondary aquifer exists, there
is an overlying surficial aquifer that yields as much or more than the
secondary aquifer. If there is a need for a larger supply (irrigation, public
supply, industry), a deeper Floridan Aquifer well is usually drilled.

Water Chemistry
Secondary aquifer water chemistry is not as well defined as surficial
or Floridan Aquifer chemistry due to the small number of wells completed
into the aquifer (15 in the study area) available for sampling and the lack
of areal Hawthorn Formation stratigraphic data. In northern Columbia
County there are five Hawthorn members (Miller, et al., 1978b). The
lower three-C, D, and E-are permeable enough to contain water, while
C is the most productive. In eastern Hamilton County, Members D and
E appear to be absent or discontinuous, while in Suwannee County there
are no data. Facies changes are common throughout the Hawthorn
Formation, and the lithology varies from sand to clay to carbonate in
all manner of proportions. This causes difficulties in attempting to
characterize the water.
Secondary artesian water is characterized by high relative values
for fluoride and orthophosphate. These parameters are strongly corre-
lated in Cluster 3 in Figure 12. The high values for fluoride and ortho-
phosphate (Figure 15) are a result of dissolution of fluorapatite, the most
abundant phosphate mineral present in the Hawthorn Formation
(Lawrence and Upchurch, 1976). Figure 15 also reveals that secondary
artesian water has high relative values for the parameters potassium,
sodium, and pH. Montmorillonite clays within the Hawthorn readily sorb
-otassium and sodium ions, and weathering those clays can release the
sodium and potassium into solution (Garrels and Christ, 1965). The pH
nay be high because of high sodium and orthophosphate values that
promote a higher pH due to hydrolysis reactions influenced by
:hosphates and carbonate salts (Hem, 1959).
Trilinear plots of secondary aquifer ion ratios (Figure 16) show that
as far as the major anions and cations are concerned, secondary arte-
sian water is nearly identical to the calcium-magnesium-bicarbonate
Floridan artesian water. These ratios are relative percentages and the


stoichiometric equations are for the same reactions so the relative per-
centages of ions for the two types should be the same (Robert Hull,
USGS, Tallahassee, FL, personal communication, 1980). In the adjacent
Santa Fe River Basin, secondary artesian water from the Hawthorn
Formation is of the calcium-magnesium-bicarbonate type (J.D. Hunn,
USGS, Tallahassee, FL, written communication, 1980). In the Upper
Suwannee Basin the secondary artesian aquifer is always underlain by
the artesian portion of the Floridan Aquifer, and there are varying degrees
of hydraulic conductivity between the two.


Configuration and Extent
In north central Florida the potable water-bearing portion of the
Floridan Aquifer is comprised of carbonates deposited during the Tertiary
Period. The portion of this aquifer that extends into Georgia is named
the principal artesian aquifer. The base of potable water in the Floridan
Aquifer is estimated to range from approximately 1000 feet below land
surface (-900 feet msl) in the southern part of the study area to more
than 1250 feet below land surface (-1150 feet msl) in the northern part
(Klein, 1975) (Figure 19). These depths are generalized from widely
scattered data, and test wells need to be drilled to verify the base of
potable water. Krause (1979) reports highly mineralized, nonpotable
water in the Valdosta, Georgia, area as shallow as -330 feet msl.
The deepest (oldest) formation in the area that contains potable
water is the Lake City Limestone (Eocene). Water from the lower portions
of the Lake City contains high sulfate concentrations. From oldest to
youngest, the other carbonate units containing potable water are the
Avon Park and Ocala Group (Eocene), the Suwannee Limestone
(Oligocene), and the St. Marks Formation (Miocene). Together these units
comprise the Floridan Aquifer. Even though they may be hydraulically
connected to the older carbonates, basal Hawthorn carbonates are not
considered to be a part of the Floridan Aquifer in this area because of
differences in water chemistry, potentiometric heads, and transmissi-
vities. Most of the domestic Floridan wells in Hamilton and northern
Suwannee counties tap the Suwannee Limestone for water. In northern
Columbia County the Suwannee is thin or absent, and most Floridan wells
are completed into the Ocala Limestone. A few municipal and industrial
wells penetrate rocks older than the Ocala in the study area.
Most of the groundwater circulation takes place in the upper 200
to 300 feet of saturated limestone (J.D. Hunn, USGS, Tallahassee,
Florida, written communication, 1980). Suwannee River Water Manage-
ment District geophysical and drillers' logs were examined to locate
cavity zones in the Floridan Aquifer. Data revealed that of all reported
cavities in the study area, nearly two-thirds occurred at formational
contacts. Most occurred at the contact between the Suwannee



1000 A--------- 8 A K E R
l ooptI -f -f" I COLUMBIA I


A Y L 0 R U N I CL Y

500 Ir

m --. Line Showing Inferred Depth t' 1250
to Base of Potable Water GILCH\ST'
In the Floridan Aquifer 11IF / S
Contour Interval 250 Feet 10
Datum is Land Surface 250 A A HUA
(Modified from Klein, 1975) X I E PUTNAM 0

S2750 -
L V Y %
S" r --_ M A R I 0 N

.. 2 250 500
Figure 19. Inferred depth to base of potable water in Floridan Aquifer.


Limestone and the overlying Hawthorn, but the Ocala Group-Suwannee
Limestone contact is also a major cavity zone. Area springs exhibit ex-
tensive horizontal cave systems at these contacts (Fisk and Exley, 1977).
These systems are known to extend for miles, and velocities within the
conduits commonly reach five feet per second (Dave Fisk, SRWMD,
personal communication, 1979).
The upper one-half of the Suwannee Limestone also contains signi-
ficant cavity zones. A high degree of secondary porosity has developed
in the upper Suwannee since it is, generally, the first major carbonate
unit encountered by the downward percolating acidic ground water,
especially where the aquifer is in a leaky artesian or nonartesian con-
dition. The upper portion of the Suwannee Formation is also a former
erosional surface, is not as lithified as the lower Suwannee because of
less compaction in early diagenesis, and probably developed a degree
of secondary porosity during this weathering period.
In the areas south and east of White Springs, the Suwannee
Limestone is relatively thin (less than 20 feet thick). Where this situation
exists, the entire Suwannee and Upper Ocala are potentially cavernous.
Cavity zones up to 25 feet thick are common. The limestone along the
rivers has developed high secondary porosity partially due to dissolution
by acidic river waters. During flood stages, a large volume of river water
recharges the Floridan Aquifer along the river corridor. In areas that are
nonartesian now, or have been in the geologic past, solution cavity
development takes place at the water table and within the zone of water
table fluctuation. Where the aquifer is artesian, most solution takes place
at the contact of the saturated carbonates with the overlying confining
The upper surface of the carbonate rock that comprises the Floridan
Aquifer is depicted in Figure 20. The highest elevation of limestone is
approximately 100 feet above msl in the Live Oak area. Limestone is
at land surface here and is quarried. The carbonates form a domal feature
that underlies most of Suwannee and western Columbia counties. From
the dome the rock surface drops at a steep gradient (400 feet over 30
miles) to the east-northeast to more than 200 feet below msl within the
study area.
The Floridan Aquifer has been described extensively in the literature.
Miller, et al. (1978b, p. 28) sum it up very well:
It consists of a thick and really extensive sequence of in-
terbedded limestones and dolomites of Paleocene to mid-
dle Miocene age. Although these carbonate rocks differ ver-
tically and horizontally in texture, porosity, and permeabili-
ty, they can be treated as a single hydrologic unit in that,
overall, their internal hydrologic dissimilarities are minor
compared with dissimilarities between them and other
units. Groundwater storage and movement in the Floridan
takes place through a complex admixture of intergranular
openings, cavities, and solution cavities.


O 0 25 0


25 25 50

1 0 3 6 Mi.
0 2 4 6 8 Km. 75
75 -*. Contour on the Upper Surface of the
Carbonate Rock That Comprises
the Floridan Aquifer in Feet MSL
(Dashed Where Eroded)
Contour Interval 25 Feet


St. Marks Formation

Suwannee Limestone

Ocala Group

-"-25 1s5 -50 -75-100-125-150-175-9nn

F ,


Figure 20. Structural top of Floridan Aquifer.








Areas of Artesian and Nonartesian Conditions
Two types of hydrologic conditions exist in the Floridan Aquifer.
Artesian conditions prevail beneath the Northern Highlands (Figure 21).
Where the Floridan is confined on top by relatively impermeable strate
of the Hawthorn Formation, it is under artesian pressure. Under artesian
conditions, water levels in tightly cased wells penetrating the aquifer
will rise above the altitude of the saturated carbonates.
Nonartesian conditions prevail in the Coastal Lowlands. The Floridan
is not confined on top, and the saturated zone of the aquifer is at
atmospheric pressure. Water levels fluctuate from below the upper
surface of limestone to above it into the overlying sands, depending on
the amount of water in storage. The potentiometric surface of the
Floridan is higher where the aquifer is in an artesian condition; therefore,
groundwater flow in the Floridan Aquifer is from the artesian to the
nonartesian portion.
The artesian-nonartesian boundary in Figure 21 was described by
superimposing potentiometric surfaces onto the structural top of the
Floridan Aquifer map (Figure 20). Along the boundary line, the highest
limestone encountered is the Suwannee Limestone. There is a small area
in the northwest portion of the study area where the St. Marks Forma-
tion is the highest limestone encountered. Artesian areas are defined
where the potentiometric surface is above the top of the limestone.
Nonartesian areas are defined where the potentiometric surface is below
the top of the limestone. The transition zone between the artesian and
nonartesian portions migrates as water levels fluctuate. During periods
of recharge to the aquifer, the potentiometric surface rises. This results
in an areal increase of artesian conditions. The increase is greatest in
the Alapaha Subbasin where groundwater fluctuation is greatest.
The artesian-nonartesian transition zone during high water levels
(maximum artesian area) generally concides with the crest of the Cody
Scarp which follows the 100- to 110-foot msl surface contour lines.
These contours also separate the Northern Highlands from the Gulf
Coastal Lowlands as seen in Figure 21. Along the Cody Scarp there is
a high degree of physical and chemical weathering. Mature karst develop
ment is evidenced by deep, steep-sided sinkholes, dolines, sinkintj
streams, and, at the base of the scarp, artesian springs. The artesian-
nonartesian boundary also generally coincides with the 40- to 50-foo:
msl contour lines on the top of the Floridan Aquifer (Figure 22). Arte-
sian conditions prevail wherever the top of the limestone is less tha,
40 feet above msl. Since the transition zone generally follows th
110-foot msl surface contour, the Hawthorn has been eroded to a 50
to 70-foot thickness along this boundary (Figure 23). It becomes apparel
that thickness of the overlying, confining Hawthorn strata is related t<
artesian conditions. Less than 50 to 70 feet of basal Hawthorn does no
appear to constitute a good confining bed. Where the Hawthorn has beei
eroded to a thickness of less than 70 feet, it has become solution-riddle:
and is leaky and discontinuous. Along the transition zone, up to 50 fee'


R 11




0 "

1 0 3 6Mi. Z
1 1 1 .r I I I,
02468 Km. 0
Cody Scarp
Northern Highlands
Arteslan-Nonarteslan Transition Zone

Figure 21. Artesian-Nonartesian transition zone superimposed on the physiographic map.

2--250 -75-100-12-150-175200
R 19 E
50 I L Ta N 0.



Carn _ome 0he iX \ "L e 0\ \ I Jz
o -10 200
M AD 18 0 N "T 1 S


CO Rock Tt Cpr100 0s
(Dashed Wher0 Mi. -75
Ii 1 11 1 75 05
0 2 4 8 8 Km. SU WAN NE -50

75 *.... Contour on the upper surface of the
Carbonate Rock That Comprises the ke. -25
Floridan Aquifer in Feet MSL
(Dashed Where Eroded) 75 0
Contour Interval 25 Feet
Artesian-Nonartesian Transition Zone 25

.,,, ,, ^,h.,L,, nn-+mS1.n transition zone superimposed on the structural top of the Floridan A/n.ifr.

7 O
50 Ru E100 128
~S 4
Lj i '% P'; -~

I G E 0 R G I A


Line of Equal Thickness of Hawthorn
Formation in Feet
Contour Interval 25 Feet

Figure 23. Artesian-Nonartesian transition zone superimposed on the isopach of the Hawthorn Formation.



of basal Hawthorn can be carbonate rock that directly overlies Floridan
carbonates. The Hawthorn carbonates have varying degrees of hydraulic
connection with the underlying Floridan. They constitute a separate
aquifer from the Floridan, however, since they exhibit different hydraulic
heads and different water types.

Potentiometric Surface Fluctuations
River basin boundaries for the Suwannee River above the
Withlacoochee River, Alapaha River, and Withlacoochee River subbasins
are shown in Figure 24. Oligocene and Eocene carbonates that comprise
Georgia's principal artesian aquifer (equivalent to the Floridan Aquifer)
outcrop in the northwest. This aquifer dips southeast beneath Upper
Miocene and younger coastal plain sediments and underlies all of the
coastal plain of Florida. The aquifer is recharged generally in the out-
crop area and locally wherever the overlying sediments are thin, discon-
tinuous, removed, or leaky. Since 94 percent of the Alapaha and 69 per-
cent of the Suwannee River above the Withlacoochee subbasins lie in
Georgia, precipitation in the outcrop area and in the upper river basin
area is the major source of recharge to the artesian portions of these
basins of Florida.
Georgia has two climatolotical regions in the area of concern the
South-Central Divsion and the Southeast Division (NOAA, B,
1949-1978) (Figure 24). Precipitation data from these two divisions
(Table 5) were correlated with fluctuations in the potentiometric surfaces
in the Alapaha and Suwannee Basins in Florida. The South-Central Divi-
sion encompasses all of the Alapaha and Withlacoochee subbasins in
Georgia and approximately two-thirds of the Suwannee River above the
Withlacoochee River Subbasin in Georgia. The eastern one-third of the
Suwannee above the Withlacoochee Subbasin is within the Southeast

Table 5. Mean monthly rainfall in inches. Georgia-1977 through 1978.

May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr
a 2.25 3.79 5.82 6.66 5.20 1.13 4.19 5.11 6.33 2.96 4.10 3.20
b 2.40 2.72 5.01 6.77 7.82 1.08 4.19 5.89 4.15 2.91 3.19 2.55
a = South-Central Division
b = Southeast Division

Generally, the potentiometric highs in the aquifer outcrop area ir
Georgia are the controlling factors responsible for the pressure head ir
the principal artesian aquifer in Georgia and part of the Floridan Aquife
in extreme north Florida (Figure 25). The potentiometric high (approx
imately 100 feet above msl) in Brooks and Lowndes counties, Georgia,


Climatological Region Boundary
River Subbasin Boundary
Outcrop Area of Principal Artesian
Aquifer (From Lawton 1977)
Wells with Continuous Recorders

Sou theas t




0 o/ .0 o

40 d-ttas

t *f ;o ....
o' & o "o ",.,o, ,=.=r

Figure 24. River basin and climatological region boundaries for the
Suwannee River above the Withlacdochee, Alapha, and
Withlacoochee River subbasins.


Potent metric Surface in Feet "' I
above Mean Sea Level
Cantour kterval 10 and 20 Feet.
Modified from LaugNh 1976, Rosenau and '" I IET
Meadows 1977, Fisk and Rosenau 1977 b, unpublished
USGS 1976 Water Level Data Jacksonville, FL)

Figure 25. Potentiometric surface of principal artesian-Floridan
Aquifer in south-central Georgia and north-central Florida.

--I ~-~e~ud_ I IL- L 6fl~ I C



> m m
35 30 25 30 o
e White


50 Contour Line Potentlometric Surface
n Feet above Mean Sea Level 30
"711 Inferred \
SData 30354045 50onts ,

Contour Interval 6 Feet 30354045 50 U
Figure 26. Potentiometric surface of the Floridan Aquifer in north-central Florida, August 1977.


is the source of the pressure head that moves ground water southward
across the state line into Madison, Hamilton, and Columbia counties,
Florida. The high in the area around Valdosta is created by a high rate
of recharge that occurs primarily as flow from the Withlaroochee River
and other streams enters the principal artesian aquifer via sinkholes and
solution cavities. Groundwater also enters the study area from the east
and northeast. A hydrologic divide extends southeast from Echols
County, Georgia, to Putnam County, Florida. Ground water moves south-
easterly from this divide into Nassau, Duval, Clay, and Putnam counties
and westerly into the Suwannee River Basin (Figure 25).
Drought conditions existing in north-central Florida in the summer
and fall of 1977 (Musgrove and Shoemyen, 1979). In August 1977 the
potentiometric surface of the Floridan Aquifer approached record low
levels (Figure 26). Total precipitation for the three-month period prior
to this August measurement was below normal. Total rainfall in Georgia's
South-Central Division was 11.86 inches, 2.69 inches below the 30-year
mean; rainfall in the Southeast Division was 10.13 inches, 6.05 inches
below the mean (NOAA, 1949-1978 B). Low rainfall and high ET ac-
count for the low potentiometric conditions in the Floridan Aquifer in
north-central Florida in August 1977.
The lowest groundwater levels in the study area in August 1977
occurred at the confluence of the Suwannee and Withlacoochee rivers.
At this point, the Suwannee River exits the upper basin. Water levels
of 25 feet msl were measured here, 127 miles from the river mouth.
Levels as low as 40 feet above msl extended to the Georgia-Florida line.
The area within the 45-foot contour in the western portion of the study
area indicates a zone of major geological structural weakness extending
north through the Alapaha Subbasin. This could result in high
transmissivities in this area due to high secondary porosity which may
produce conduit flow in the subsurface. Approximately 50 percent of
the time the Alapaha River disappears underground for 17 miles in this
area. Minor geological structural control extends eastward toward White
Springs. Localized highs (>50 feet above msl) extend westward through
Lake City toward Live Oak. Other potentiometric highs are in the north-
west and northeast corners of Hamilton County. These potentiometrii
highs coincide with areas of relatively high surface elevations and thick
sequences of Hawthorn strata. As the 50-foot contour continue;
southeast through Hamilton County, it exhibits an eastward extendin 1
lobe that encircles White Springs and extends into Columbia County
This configuration appears repeatedly on water level maps and is signif
cant because it coincides with the first outcrop of the Suwanne,
Limestone along the river. This is the first point of interconnection when
water may be exchanged between the Floridan Aquifer and the Suwan
nee River depending on river stage and aquifer head. The outcroppin!
limestone occurs at 50 feet above msl; and, at low river flow, artesiar
springs appear along both sides of the river as the aquifer discharges
directly into the river.

T2 N

0 M0

MAD/O* n c T1S

40 M
o o :o T I S

O 2 4 6 8 Km. U AN ^^E CO. e/ .

T3S 0.

3 Data Points 0S
50 Contour Line Potentiometric Surface in Feet 30
above Mean Sea Level
251 1 1
-- inferred 303540 45 50 S
Contour Interval 5 Feet
Figure 27. Potentiometric surface of the Floridan Aquifer in north-central Florida, November 1977.

-r a a ,11 r I I L ~L --- --

+1 to +2


0 0 T2N


Area of Net Change in Water Levels

within the Foridan Aufer in Feet

Area of Net Change In Water Levels

within the Floridan Aquifer in Feet

Figure 28. Net change in the potentiometric surface in Floridan
A,-..i-far in nr -._er%, lrr>+ml Il h"rlr a Allt-llS t 1077 to Al. .--m.. -Y"


From August to November 1977, total precipitation for south-central
3eorgia was about 12.99 inches, 1.31 inches above the mean. Precipita-
ion for southeast Georgia was 15.67 inches, 0.11 inches above the
nean. Since water level conditions were already near record lows and
:he rivers were at very low flow, water levels continued to decline over
:nost of the area in spite of average rainfall. The November 1977 poten-
tiometric map (Figure 27) is quite similar to the August 1977 map (Figure
26). Net groundwater level fluctuation-mostly decline-from August
to November is shown in Figure 28. Water levels declined over most of
the study area. The shaded areas exhibit the greatest fluctuations. The
three linear northwest-southeast trending areas are coincident with
postulated linear trends of subsurface fracture systems (zones of struc-
tural weakness inferred to have high secondary porosity). A linear trend
of sinkholes in the area of maximum fluctuation near Lake City may
represent the surface expression of a subsurface fracture system
(Lawrence and Upchurch, 1976). The area of high fluctuation coinciden-
tal with the Suwannee River is an area where the Suwannee Limestone
outcrops. The river here flows along the same northwest-southeast linear
trend of subsurface fracture systems. The northwest-southeast trending
reach of the Alapaha, southeast of Jennings, contains dozens of
sinkholes through which the Alapaha River disappears underground much
of the time. This is the most dynamic area in the SRWMD, and water
levels fluctuate up to 30 feet. All three of these areas exhibit higher
transmissivities because of higher secondary porosity and permeability.
From November 1977 through January 1978, south-central Georgia
received 15.63 inches of rainfall, 6.19 inches greater than the mean.
The Southeast Division received 14.23 inches, 6.18 inches greater than
the mean. Wide areal winter precipitation combined with low ET rates
to replenish the aquifer. In the Alapaha Subbasin the resulting poten-
tiometric surface was highest in the Alapaha River corridor, and contour
lines indicate that river waters flowed laterally as well as downstream
(Figure 29). River water at this time was recharging the aquifer vertical-
ly and laterally and was mixing extensively with Floridan Aquifer waters
(Ceryak, 1977). Water levels rose as much as 29 feet during this three-
month period (Figure 30). The area of least fluctuation on Figure 30 is
i1i the confined area where the Floridan Aquifer underlies the Northern
Highlands in eastern Hamilton and Northern Columbia counties-the area
farthest away from areas of recharge. Large increases in groundwater
torage occurred in the Suwannee River corridor because increased
recipitation created high river stages. Along the river where limestone
rops out and springs appear, high river stage caused the springs to
averse flow; and the river water was directly recharged into the aquifer.
By May 1978 the potentiometric surface (Figure 31) declined to a
configuration similar to that which it had exhibited in the summer and
all of 1977 (compare Figures 26 and 31). Total rainfall for Georgia's
;outh-Central Division in the three-month period preceding May 1978
/as 10.26 inches, 2.74 inches below the mean. The Southeast Division


received 8.65 inches, 2.21 inches below the mean. The area of the most
dramatic decline again was along the Alapaha River where water level
dropped as much as 18 feet (Figure 32). The Suwannee River corridor
also experienced a relatively large water level decline, while again the
least fluctuation occurred beneath the confined highlands in eastern
Hamilton and northern Columbia counties. The river corridors experience
the widest range of water level fluctuations. Considerable amounts of
water move into bank storage during high river stages and slowly drains
back as the stage declines. Transmissivities along the river corridors are
probably higher because the rivers are thought to occupy zones of
weakness (i.e., faulting and jointing) where secondary porosity has in-
creased due to greater groundwater dissolution of the limestone.
Appearances of lineaments confirm the coincidence of the river paths
and zones of weakness (Beatty, 1978; Vernon, 1951).


"45 0 : m .I

Sk 55
Contour interval Feet 303540 5 50

Figure 29. Potentiometric surface of the Floridan Aquifer in north-central Florida, February 1978.

Data Points 35
- Contour Line Potentiometric Surface 30
in Feet above Mean Sea Level
Contour interval 5 Feet 303540 45 50

Figure 29. Potentiometric surface of the Floridan Aquifer in north-central Florida, February 1978.


o n1 f +10+15+20 A13 E +20 +15 +10 R is a + R 17 E R 19 E

+10 ,; 0 J -


t n T3
p t

# A Dat8 Points C r
Whil e an

+ 1 0 0 0 0 0 E O L U M B A CE C O

0 Data Points

Contour Intervals 6 Feet f the F ridar
t hane the .tent.om..c.
Figure 30. -et t ange

RCa- 63 60 f G d a -


50 m*

45 o
MAD A D **1 8 0 O0

AV *.. <
40 35 35 40 N -,1h, ,0 m
\* L 0 o

Live 0
1 0aMi COLUMB1A d O
0 2 4 0 8 Km. 2
U NE 0.

_City 55
e Data Points
50- Contour Line Potentiometric Surface 35
In Feet above Mean Sea Level
Contour Interval 5 Feet 35 40 45 50
Figure 31. Potentiometric surface of the Floridan Aquifer in north-central Florida, May 1978.

15 R 11E


00 '2 N


i. / o *" CS
I. = : >
1\ C s
~'I0 *

0 2 4 6 8 Km. U W A N E C. g
S T38

Data Points L as -'

Line of Equal Decline in Water Levels 0 0
within the Floridan Aquifer in Feet
Contour Interval 5 Feet

Figure 32. Net change in the potentiometric surface of the Floridan
Aquifer in north-central Florida, February to May 1978.


Water Level Relationships
The potentiometric high in Brooks and Lowndes.counties, Georgia,
cefines a recharge area. Groundwater within the Floridan Aquifer flows
from this area into the Northern Highland areas of Hamilton, northern
Columbia, Baker, and eastern Suwannee counties, Florida (Figure 25).
Seasonal fluctuations in precipitation and ET cause corresponding
changes in streamflow stages and in the groundwater levels of the
principal artesian or Floridan Aquifer. Areas with relatively high water
levels tend to be recharge areas. The area around Valdosta, Georgia,
is a recharge area. A portion of the flow of the Withlacoochee River (up
to 112 cfs) directly recharges the Floridan Aquifer through sinkholes in
the river bed (Krause, 1979). The potentiometric surface fluctuates more
than 20 feet (between 73 and 100 feet above msl). The structual top
of the Floridan Aquifer near Valdosta is around 20 feet above msl; and
there is a thickness of greater than 100 feet of overlying Hawthorn, so
groundwater conditions in this area are always artesian. Figure 33 depicts
the mean monthly rainfall for the South-Central Division of the Georgia
climatological region (30-year mean). Precipitation normally is highest
in midsummer, July and August, when convectional afternoon
thunderstorms are the typical rainfall event. The other peak rainfall period
is in March, culminating a relatively high midwinter rainfall. October and
November usually have the lowest amounts of precipitation, resulting
in low streamflow and groundwater levels at this time.
Figure 34 depicts the seasonal relation of precipitation, pan evapora-
tion, streamflow, and groundwater levels for the Valdosta area. Precipita-
tion for this station is nearly identical to the regional pattern displayed
in Figure 33. Streamflow responds to the winter rains and increases
through April, only to begin decreasing as pan evaporation begins to
increase. Pan evaporation is beginning to peak by April, resulting in ET
being a major factor causing streamflow to decline in the summer
months. Streamflow decreases as bank storage is depleted. Groundwater
levels decline in the summer and usually continue to drop into November,
the month that commonly displays the lowest groundwater levels and
lowest river stages. Stream and groundwater levels rise in December
when the winter frontal systems begin. The long-term relationship be-
tween precipitation, streamflow, and ground water levels for the
Valdosta area also emphasizes a direct correlation between these three
viriables (Figure 35).
For the year 1977 a comparison was made between daily ground-
v ater levels, stream discharge, and precipitation for Valdosta (Figure
3). During the winter months, each rainfall event is followed by an
ir mediate rise in the level of ground water in the principal artesian
a iuifer. The water level peak occurs within two days and often within
c ie day of the rainfall event. Water levels then decline until the next
r infall event. When summer rains begin in late May, ground water levels
s ill respond within two days of the precipitation; however, due to higher
E rates, the magnitude of water-level rises is lower than in the winter





_____ F M T M --5,, A 5 --5 -- -N -- D.

Figure 33. Mean monthly rainfall for the south-central Georgia
climatological region (30-year mean).
months. Barometric pressure changes cause fluctuations in groundwater
levels in confined aquifers. Frontal systems moving through the area
cause fluctuations of around one foot every three to seven days in August
and September.
Streamflow also corresponds directly with rainfall in the winter
months; streamflow usually is very low in summer and shows little
response to the summer rainfall since ET rates are highest and runoff
in the upper basin is minimal. Streamflow response to rainfall is again
more direct at the end of summer when ET rates begin to drop.
Throughout the year a one-inch rainfall event can cause groundwater
levels to rise two feet or more. One to two inches of rainfall usually'
causes a two- to five-foot positive response in water levels. This response ,
is slightly greater in winter than in summer. There is nearly 20 feet oF
yearly fluctuation in USGS Well 304949083165301 in Valdosta
Georgia. This high degree of groundwater fluctuation is typical c
recharge areas. Also common in recharge areas is a water level rise fror
mid- to late summer in response to the convectional rains. Over th,
10-year period from 1968-1977, Valdosta water levels experienced
summer rise of nine for those years. Rises ranged from one to eight fee:





90 -

Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Figure 34. Seasonal relation of mean monthly precipitation,
evaporation, streamflow, and groundwater level, Valdosta area.

Valdosta 4 NW

I I I I I I I i
I I I I I I I I m I I

Tifton Experimental Station

l lI I I I I



< W




Alapaha River at Statenville

Well 185-7


Valdosta 4 NW



I I I I I I VI I I I I l I Il l |
SlAlapaha River at Statenville

| I I I I I I I I I I I I I I -

1960 1965 1970 1975

Figure 35. Long-term relation of precipitation, streamflow, and
groundwater level, Valdosta area, 1957-1975.


Z 70



< 40


S- I


^1 0




Well 185-7

I I I I I I I I I i I I I


I I I I I I I I I I I I I I. .

Sl r M A M J J A S U N D
SWater Level in Feet Below Land Surface
Stream Discharge, CFS
Precipitation in Inches

Figure 36. Daily groundwater levels, stream discharge and precipitation for Valdosta, Georgia.




Figure 37. Groundwater level fluctuation, Valdosta, Georgia, and
Jennings, Florida, 1968-1977.


with an average of 3.3 feet. Levels do not usually attain the altitudes
of February and March, but a five-foot rise is common (Figure 37).
Jennings, Florida, (SRWMD Well + 021202001) in the Alapaha Sub-
basin (Figure 24) is 20 miles southeast of, and down the potentiometric
gradient from, Valdosta. Groundwater levels at Jennings fluctuate from
35 to 68 feet above msl, a 33-foot fluctuation. The top of the Floridan
Aquifer is at 50 feet above msl; and there is nearly 100 feet of overly-
ing, confining Hawthorn sediments. This well is on the artesian-
nonartesian boundary and can be either, depending on the water level.
This area exhibits mature karst development and is also a recharge point.
Nearby, the entire Alapaha River flows underground about 50 percent
of the time through numerous streamsinks (Ceryak, 1977). These
streamsinks have been known to accept 770 cfs of the river's flow and
contribute to more than 30 feet of fluctuation in water levels in the
underlying Floridan Aquifer. Figure 37 compares water level fluctuations
in Valdosta with Jennings. The hydrographs are nearly identical in times
of high and low water level peaks. They differ only in amount of
fluctuation. Total yearly fluctuation at Valdosta can be 20 feet, whereas
in Jennings it is around 30 feet. For 16 years of record at Jennings (1962
to 1977) there was a midsummer water level rise for 12 of those years,
ranging from a 1- to 19-foot rise with an average rise of 4.7 feet.
Jasper, Florida, (SRWMD Well +011407001) is located 12 miles
southeast of Jennings, 30 miles southeast of Valdosta (Figure 24), and
down the potentiometric gradient from Jennings. Water levels fluctuate
from 30 to 55 feet above msl, a 24-foot fluctuation. The top of the
Floridan Aquifer at Jasper is at 50 feet above msl. Conditions are nonarte-
sian most of the time and only become artesian during times of extremely
high water levels. There are 60 to 70 feet of confining Hawthorn, and
the confining bed is leaky due to karst development in the area. Jasper
is on the topographic divide between the Alapaha and Suwannee River
above the Withlacoochee Subbasins and is also in a recharge area.
The Valdosta monitor well is three miles from the Withlacoochee
Fiver and less than six miles in a direct line from a streamsink area. The
Jennings well is one mile from the Alapaha River and less than two miles
f:om the nearest streamsink. The Jasper well is five miles from the
Alapaha and seven miles from a streamsink area. The Jennings well pro-
bably has the greatest water level fluctuations because it is only one
r ile from the river, is influenced by bank storage, and is reflecting large
r .ovements of water in and out of the aquifer (Dick Johnston, USGS,
/ tlanta, Georgia, written communication, 1980). The sinks at Jennings
Save been known to accept 770 cfs of Alapaha River water (Ceryak,
977), while the sinks in the Withlacoochee River near Valdosta have
en known to accept 112 cfs (Krause, 1979).
In Figure 38 daily water level fluctuations at Jasper are compared
t those at Valdosta for the period June 1976 to November 1977.
a asonal fluctuations are slightly greater at Jasper than Valdosta.
summer groundwater levels fluctuate more in Valdosta because the well






Figure 38. Daily groundwater level fluctuation, Valdosta, Georgia, ant
Jasper, Florida, June 1976 through November 1977.


ts closer to the point of recharge from the Withlacoochee River and is
also subject to bank storage effect in summer. The Alapaha River flow
is minimal and entirely underground at Jasper in the summer. In winter,
however, when the Alapaha River flows above ground also, river water
is recharged laterally into the Floridan Aquifer; and the Jasper well
responds in less than 24 hours to fluctuations in the Alapaha River (Figure
39). Under these conditions, Jasper water levels fluctuate up to 10 feet
higher than those in Valdosta.


I Alapaha River at Jennings, FL

I 60------
S~ r roundwater Level at Jasper, FL
(SRWMD 4011407001)
>50 ----


30 A S O N D F M A M J J A 8 0
1976 1977

Figure 39. Daily groundwater level fluctuation at Jasper, Florida,
compared with daily stage of Alapaha River near Jennings, Florida,
July 1976 through October 1977.
USGS test well OK 8 IWell 304943082213701) is located east of
S:ephen C. Foster State Park on the western edge of the Okefenokee
S Namp. This area is 50 miles due east of the Valdosta recharge area.
V withinn the Suwannee River above the Withlacoochee Subbasin in Georgia
(I igure 24) and down the potentiometric gradient from Valdosta, the
p atentiometric surface of the principal artesian aquifer fluctuates 10 feet
fi -m 48 to 58 feet above msl. The limestone aquifer underlying the site
d 3s to the northwest, and the top of rock is approximately -350 feet
n sl. There are more than 400 feet of confining Hawthorn Formation.
I ie water level fluctuation at this site is typical of a deeply buried artesian
a luifer away from the recharge area (Figure 40). Total fluctuation for
1 -77 was only four feet compared to 21 feet at Valdosta, 26 feet at
J isper, and 38 feet at Jennings. Water level response in well OK 8 lags
ft om 5 to 20 days behind water level fluctuations in the Valdosta well,


100 1 1 1
Valdosta, GA
(USGS 304949083165301)


C 85 -

S80 -----

L 75

_ 70


Fargo, GA
(USGS OK8 304943082213701)
Osceola Nat.
Forest. FL ,
(USGS ONF6 302251082194901) ---
50 -'

Figure 40. Daily groundwater level fluctuation at Valdosta, Georgi ;
Fargo, Georgia; and Osceola National Forest, Florida, 1977.


assumingg no recharge between the sites. It is common for OK 8 to lag
0 to 13 days behind. Mean monthly comparisons show OK 8 lagging
up to one month behind Valdosta. About 50 percent of the time OK 8
cioes have a summer peak although the highest in ten years was one
and one-half feet. Barometric pressure changes that result from frontal
systems crossing the area affect the water levels most dramatically in
August and September. Valdosta water levels have gradually risen nearly
ten feet over the past ten years (Figure 37). During this same period,
there has also been more than 26 inches of total rainfall above the norm
in this climatological region. The Stephen C. Foster Park water levels
have declined three feet over the same period. This apparent decline is
probably due to regional water level decline caused by increased pump-
age and drawdown in the Fernandina, Florida; Jacksonville, Florida; and
Brunswick, Georgia, area about 50 miles east of the study area (Dick
Johnston, USGS, Atlanta, GA, written communication, 1980).
USGS test well ONF 6 (Well 302251082194901) in the Osceola
National Forest is 30 miles south of OK 8 and approximately 55 miles
southeast of the Valdosta well (Figure 24). At this site the Floridan
Aquifer is always under artesian conditions as the top of rock is at -192
feet msl; and there is 286 feet of overlying, confining Hawthorn, typical
of the deeply buried, artesian Floridan Aquifer far from the recharge area.
Water levels in this well have only fluctuated five feet, from 51 to 56
feet msl, over the period of record (August 1976 to June 1978) (Figure
40). This well has the least amount of fluctuation in the study area. This
is to be expected. This area is in the center of the flat saddle between
the potentiometric highs in Brooks and Lowndes counties, Georgia, and
Putnam, Bradford, and Alachua counties, Florida (Figure 25). In this
saddle the potentiometric surface is relatively flat over an area greater
than 250 square miles. The resultant groundwater flow is eventually to
the east-northeast to the Atlantic Ocean and to the west-southwest in-
to the Upper Suwannee River Basin in Florida.
The structural top of the Floridan Aquifer at well OK 8 is more than
150 feet deeper than at well ONF 6; and, therefore, approximately 150
more feet of overlying Hawthorn occurs there. Otherwise, hydrogeologic
conditions are similar under the Okefenokee Swamp and Osceola
National Forest. Water level hydrographs for the two wells for 1977 are
nearly identical (Figure 40). Daily peaks lag a few days behind in ONF
6 as it is slightly farther from the Valdosta Recharge area. The Osceola
national Forest area may receive some recharge from the southeast, but
t .e potentiometric surface gradient is steeper from the direction of
\ ildosta, so the majority of groundwater inflow is probably from the
r )rthwest. ONF 6 responds to the winter rainfall in the recharge area.
F uctuations due to barometric pressure changes are more pronounced
ii mid- to late summer; but in 1977, as in OK 8, water levels continued
t decline through the periods of summer rainfall. Miller, et al. (1978b)
c )mpared the stage of the Suwannee River at White Springs to water
I vels in wells tapping the Floridan Aquifer in Osceola National Forest.



The direct correlation between precipitation and streamflow in the
recharge area has.been shown in Figure 36. Miller states:
Wells 1A, 3A, and 6A are located progressively farther
eastward from the river. The magnitude of groundwater rise
at times of high stream stage decreases progressively
eastward away from the river.
See Figure 41. Well 6A is well ONF 6. This figure once again
demonstrates that groundwater fluctuations decrease with distance from
the source of recharge.
High river stage at White Springs causes White Sulphur Spring and
other down-river springs to reverse flow. Potentiometric maps (Figures
26, 27, 29, 31) reveal that in the White Springs area groundwater flow
is toward the river. Just as these maps and others (Miller, et al., 1978b)
reveal isolated potentiometric highs in the surrounding aquifer, the river
can have periods of high stage also; but these localized river stage highs
do not reverse the regional groundwater flow entering the Suwannee
Basin from the east-northeast.
Lake City, Florida, (USGS Well 301031082381001, SRWMD
-041705001) is 20 miles southwest of, and down the potentiometric
gradient from, ONF 6 (Figure 24). At Lake City there are 72 feet of
confining Hawthorn, and the top of the Floridan Aquifer is 50 feet above
msl. Groundwater levels have fluctuated up to 18 feet in the past but
since 1950 have only fluctuated 10 feet, from 47 to 57 feet above msl
(Figure 42). Water levels at Lake City are influenced by sinking streams
and lakes in the area that occasionally drain underground. Most of the
major water level fluctuations in the Lake City area are the result of
variations in rainfall. Minor fluctuations are caused by changes in
atmospheric pressure and by earth tides in the more confined portion
of the aquifer. Finally, large fluctuations in the potentiometric surface
of the Floridan Aquifer are related to stream stage where the aquifer is
directly connected to a stream (Miller, et al., 1978b).

Aquifer Properties
Transmissivity (T) is the rate at which water of the prevailing
kinematic viscosity is transmitted through a unit width of the aquifer
under a unit hydraulic gradient. It is a property of the confined liquid as
well as the aquifer. T in ft2/day equals Kb, where K is the hydraulic
conductivity in ft/day and b is the thickness of the aquifer in fee .
Hydraulic conductivity is the volume of water at the existing kinemati;
viscosity (temperature dependent) that will move in a unit time under
a unit hydraulic gradient through a unit area measured at right angles
to the direction of flow [K(LT-1)] and measured in ft/day (Lohman, 1972,
p. 30).
Storage coefficient (S) is the volume of water an aquifer release;
from or takes into storage per unit surface area of the aquifer per unit


o 70
065 0

50 )
> 2

1976 1977

-- Stage of Suwannee River at White Springs
Well (USGS 1A ONF1 302243082360201)
--- Well (USGS 3A ONF3 302052082312401)
___ Well (USGS 6A ONF6 302251082194901)
Figure 41. Comparison of stage of Suwannee River with water levels in three wells tapping the Floridan
Aquifer in Osceola National Forest.


0O 65
-2 SRWMD -041706001

> 4)
0 USS 301031082381001
S355 -
S50-------- -- -

.E 40 -------------------------------------
35 ---------------------------







Figure 42. Long term groundwater level fluctuation, Lake City, Florida, 1948-1979.


change in head dimensionlesss). Confined (artesian) aquifers have storage
coefficients that range from 10-5 to 10-3, while most unconfined
(nonartesian) aquifers range from 0.1 to 0.3 (Lohman, 1972, p. 8).
Leakance (K '/b') is the ratio of the vertical hydraulic conductivity
of the confining bed (K') to its thickness (b '). This is a property of the
aquifer and not of the confining bed even though it is referred to in terms
of the confining bed. Units of measurement are in days-'.
To determines the T, S, and K '/b' of the (confined) Floridan arte-
sian aquifer in the Upper Suwannee River Basin, an aquifer test was
conducted. On December 27, 1978, an 800' production well at OXY's
Swift Creek Chemical Complex was pumped at 6928 gpm for 18.5
hours. A second 800' deep production well and three shallower wells
were used for observation wells. Well data and configurations are shown
in Figure 43. Of the four observation wells, two were used in the aquifer
analysis. SCD #2 is completed into the Hawthorn Formation, did not
display any drawdown, and was not used in the analysis. SC #1 is an
800' production well, cased and completed to the same depth as the
pumped well. Drawdown in SC #1 was not as great as drawdown in
SCD #3 which is 2660' further from the pumped well. This may indicate
a more direct connection between SC #1 and SCD #3 through fractures
or cavities. Less drawdown resulted in higher calculated T's for well SC
#1 that are incompatible with the rest of the data.
Assumptions are necessarily made when Theis curve matching
techniques are applied to this data. The Floridan Aquifer is considered
homogeneous and isotropic while being bounded above and below by
impermeable beds. The well is also considered to be fully penetrating
and flow to the well bore is assumed uniform. Studies by Bentley (1977)
indicate that transmissivities increase with thickness penetrated in par-
tially penetrating wells in the Florida Aquifer. Hydraulic conductivity and
therefore transmissivity does vary horizontally and vertically in this
aquifer. The presence of fractures, interconnecting cavities, and vary-
ing degrees of secondary porosity all influence the application of Theis
curve matching techniques to this data.
Distance-drawdown curves for the pumped well and the observation
wells are shown in Figure 44. Drawdown in the pumped well reached
steady state by the end of the test. The Theis composite curve matching
techniques matches s versus r2/t (s =drawdown, r= radius, t=time)
curves to the Theis family of type curves (Hantush, 1961) and yields
the match in Figure 45. This match results in a T of 190,000 ft2/day
and an S of 1.0 x 10-3. Lohman (1972, p.8) states that a storage coeffi-
,ient of a confined aquifer is about 1 x 10-6 per foot of thickness. In
zhis area the Floridan Aquifer is estimated to be about 1000-feet thick.
This would estimate the S to be 1 x 10-3. This figure matches the
calculated value of 1 x 10-3 which is a good representative value.
A leakance K 'b' between 2.6 x 10-4 days and 5.4 x
10-4 days was determined from K '/b' = 4 Tv2/r2 (Lohman,
1972, Plate 3) for a T of 190,000 ft2/day. The values for



3000 4000



-100 -r

-200 (

-300 s

-400 5




Figure 43. Generalized geology, well construction, and static water
levels at aquifer test site.

SCD3 *

Sa 0 000 M..

S 270'ooa. 800S

o Production Wel
* Observation Wel
SC1 Well Name S
80 Total Depth 5yr 9

Distance from Pumped Well In Feet


Ti T-6'

oUU 1000 1500
0 Drawdown after 40 Minutes Distance from
9 Drawdown after 18.5 Hours
Q=6928 GPM Steady Pumping Rate
*Data Points from Well SC1 Were Anomalous and Not Used

2000 2
SPumped Wellin Feet



Figure 44. Distance versus drawdown at Aquifer test site.

Pumped Well

a f n'


5- -

O *!

2 ----- ...-----------....... mms.A

-/i- --------


1 _____________

1-'X ...........--_____________





L .

Q 0.1

8CD1 r=543

8C1 Ma Ch O B20 P m
r1100 e .0 7,s5 x o
u 1
,* .J \.o 750

w(Mu) a

14 I Wu) tT 8CD3

K l' seem like small numbers, but when you test them
dfor r, t s art tt t are
(114 61.idd IfI) (1) 1, 4 ( 7,7 aio 1 i
nd t.i 1 H-04i.

confining beds and into the aquifer is equal to the head
1- 4 1 7., dd'

0c 10t 10' 10' 10 2 18

Figure 45. This composite curve matching method.

K'/b' seem like small numbers, but when you test them
for reasonableness, it becomes apparent that they are too
high. The amount of water that can leak through the
confining beds and into the aquifer is equal to the head
difference across the confining bed multiplied by K'/b' .
The natural (unstressed) head difference across the con-
fining bed is about 75'. The natural recharge rate is then
calculated to be: 75(3.9 x 10-4) =0.029 ft/d = 128
inches/year. This is more than twice the annual rainfall. The
problem, I believe, is this. Though the pumped well and the
deepest observation well are the same depth (800 feet),
their driller's logs indicate they might be producing rost
of their water from entirely different levels. For example,
the pumped well has a 5' cavity at about 540', whereas
the observation well has a 3' cavity at about 756'. Both
wells are cased to about 250' and have specific capacities
of about 700 (gal/min)/ft. It is possible that the pumped
well.derives most of its water from the cavity at 540' .
During the aquifer test, this would lower the head in the
upper part of the aquifer, but due to the effects of vertical
anisotropy, the head in the lower part would tend to remain
higher, at least for a time. Now, if the observation well


(when pumped) produces most of its water from the cavity
at 756' the lowering of the head in the upper zone by
the pumped well would cause water to migrate up the
borehole of the observation well and move out into the
upper zone. This would not only attenuate the drawdown
in the observation well itself, it would cause the observa-
tion well to act as a recharging well for the upper zone. This
would have the effect of attenuating the drawdown in the
other (shallower) observation wells tool The weakness with
this discussion is that we really don't know where the main
producing intervals are. A caliper log and a flowmeter
survey could best define the producing intervals. The
amount of water moving up into the upper zone might ap-
proximately be equal to the drawdown in the observation
well multiplied by its specific capacity 1.5' x 700
(gal/min)/ft = 1050 gal/min. This is about 15 percent of
that produced by the pumped well during the test and is
significant. (Charles Tibbals, USGS, Orlando, FL, written
communication, 1980.)
The specific capacity of a well is the rate of discharge of that well
per unit of drawdown, commonly expressed in gallons per minute per
foot of drawdown. A direct relationship exits between specific capacities
and transmissivities in.the confined region of the Upper Suwannee River
Basin. The graph in Figure 46 depicts the range of T's for specific capa-
city values in the confined Upper Suwannee River Basin.
700 -


(D 400

(9 300


r 200

25,000 50.000 75,000 100,000 125,000 150,000 175,000 200,000 225.000 250J00
Transmiselvity in FT'

Figure 46. Transmissivity versus specific capacity in the Floridan
Aquifer in north-central Florida.

SRWMDo 011436001

0 *Transmisalvlty values calculated from
aquifer test
USQ8 0102372 *
U MThese data points fit to a linear
regression line where-37.9 Is the
Intercept and .0028 Is the slope

SUSGS 0130 820622I I
.. . . .. ..r



Groundwater Development
A typical domestic Floridan well in the Upper Suwannee Basin is a
four-inch diameter well, cased between 60 and 160 feet with 10 to 50
feet of open borehole penetrating the aquifer. Water levels range from
30 to 120 feet below land surface, and a one horsepower submersible
pump yields 15 to 22 gpm with little or no drawdown.
Large irrigation systems pump up to 1000 gpm from 12-inch
diameter wells with only a few feet of drawdown.
Large industrial use wells, cased 200 feet from land surface, with
a 26-inch diameter open borehole penetrate the aquifer for 600 feet
below the bottom of the casing. These wells can yield more than 6000
gpm with up to 15 feet of drawdown.

Water Chemistry
The solution of limestone (CaCO3) or dolomite
(CaMg(C03)2) by natural waters in the presence of carbon
dioxide (C02)is probably the largest single factor responsible
for the quality of ground water in Florida. While limestone
and dolomite are only slightly soluble in pure water, their
solubility increases in natural water that contains carbon
dioxide derived from the atmosphere and, to a much larger
extent, soil air as the water percolates through the soil and
the unsaturated zone above the water table. (Larry Slack,
USGS, Tallahassee, FL, written communication, 1980)
Floridan Aquifer water is characterized by high relative values for
specific conductance, calcium, alkalinity, magnesium, pH, and sulfate.
These parameters are strongly correlated in Cluster 1 in Figure 12. This
cluster represents water of the calcium-bicarbonate type where the
typical constituents result from the dissolution of limestone, which is
essentially a massive deposit of calcium carbonate (Hem, 1959).
All limestones contain magnesium contained in the magnesium
carbonate common in carbonate rocks. The high relative values for pH
correspond with the high relative alkalinity values. High specific conduc-
tivity is in response to the high number of calcium, magnesium, and
carbonate ions in solution.
Artesian Floridan water displays high relative values for sulfate
(Figure 15). Hamilton and northern Columbia counties have always been
known to have "sulfur water" at depth. The taste and odor associated
with "sulfur water" is imparted by hydrogen sulfide gas. Hydrogen
sulfide is formed in two ways the decomposition and reduction of
organic matter in water or the reduction of sulfate in ground water. The
former is usually associated with swampy areas with abundant
vegetative matter; while in north-central Florida, the latter can be
associated with the dissolution of gypsum and anhydrite within the car-
bonates of the Floridan Aquifer. Previous investigators (Meyer, 1962;


Krause, 1976, 1979) attribute hydrogen sulfide in the Floridan Aquifer
to the reduction of sulfate in ground water at depth. Meyer associated
hydrogen sulfide with the Floridan artesian areas, overlain by a thick se-
quence of confining Hawthorn.
Krause's investigation (1979) yielded significant data and conclu-
sions concerning sulfate and total dissolved solids in groundwater. Con-
centrations of these parameters generally increased with depth in the
Valdosta area, and a zone of high concentration occurred at -330 feet
msl. Sulfate concentration increased two orders of magnitude from 23
mg/I to 2,400 mg/I, while dissolved solids increased from 114 mg/1 to
3,300 mg/I in a zone from 400 to 550 feet below land surface (Figure
47). Values for calcium, magnesium, calcium-magnesium hardness, iron,
fluoride, and strontium also increased in the same interval (Figure 47).
In Valdosta, these concentrations occur in the lower portion of the
Suwannee Limestone. High sulfate concentrations are due to inter-
granular gypsum occurring as cement. In this gypsiferous interval, a
10-foot section may contain 25 percent to 30 percent gypsum, whereas
a 100-foot to 150-foot section may contain 5 percent to 10 percent gyp-
sum (Dwayne Jorgensen, U.S. Gypsum, Saltville, VA, personal com-
munication, 1980).
In the Wellborn, Florida, area (Township 3 South, Range 15 East,
Section 16), nonpotable, highly mineralized water appears at -710 feet
msl. From -630 feet msl to -710 feet msl sulfate concentrations increase
from 41.2 mg/I to 896 mg/l. In the same interval, calcium increased from
103 mg/I to 494 mg/I; magnesium increased from 7 mg/I to 242 mg/I;
and the resulting specific conductance increased from 950 to 1725
micromhos per centimeter.
In north-central Florida, gypsum has previously been associated with
the Lake City Limestone which is deeper in the section than the
Suwannee Limestone. The structural top of the Lake City ranges from
-300 feet to -550 feet in the study area. Klein (Figure 19) has estimated
the base of the potable aquifer to be from -1000 feet to -1300 feet msl
in the study area.
Deep industrial and municipal wells (total depth -670 feet msl or 800
,eet below land surface) exhibit relatively high sulfate values (up to 65
.ng/I). There is up to 600 feet of open borehole in these wells. The ma-
ority of groundwater flow to these wells is probably in the cavernous
tones in the fresher upper few hundred feet. Data indicate a zone of non-
Totable sulfate and dissolved solid-rich water 500 or 600 feet shallower
han Klein predicted. It is possible that there is a zone of high sulfates
nd dissolved solids at depth, mixing with fresher water in the more pro-
Juctive upper zones of the Floridan, resulting in a relatively high sulfate
'alue at the pump at land surface. Water samples from deep wells in
he Valdosta area yield sulfate values from 24 mg/I to 310 mg/l. Chapter
S7-22 of the Rules of the Florida Department of Environmental Regula-
ion limits sulfate concentrations in public supply wells to 250 mg/I and
'otal dissolved solids to 500 mg/l. A public water supply system is any


U 200

< 400

2 500
z 700
U 1000



I I p I I I I I I
0 500 1000 1500 2000 2500 3000 3500 4000 4500
Relation of magnesium, calcium, sulfate, dissolved solids, and calcium, magnesium
hardness with depth


S200 Explanation
3 300 Pattern reverses to show
o 'i overlap of 'Intervals

S400 (
-i ^1
1 Maximum concentration of Iron and fluoride
0 500 recommended for drinking water


S / Iron Strontium

s 9 / oFluoride

1 100 0 I
i tooo

00 0 2 4 6 8 10 12
Relation of iron, fluoride, end strontium with depth

Figure 47. Relation of parameters with depth, Test Well 1,

Valdosta, Georgia.

SsPattern reverses to show
I overlap of Intervals
Maximum concentration of sulfate and dissolved
solids recommended for drinking water


S Dissolved solids

SI Calcium Sulfate
SI Calcium,
Magnesium magnesium hardness






system serving more than 25 persons or otherwise making water
available to public grouping or the public in general. Gypsum has been
identified in Florida Bureau of Geology well cuttings as shallow as -690
feet msl at White Springs in Hamilton County (W-7053). Further study
needs to be done in this area to locate the base of the potable aquifer
and to prevent possible upcoming of high density, nonpotable waters rich
in sulfate and dissolved solids.
An attempt was made to differentiate between Floridan artesian and
Floridan nonartesian water types. Eighty-four water samples were taken
from the Floridan Aquifer, and parameter values in Figure 15 reveal that
the artesian Floridan has higher values for all parameters except nitrate
and calcium. These high values are probably approaching equilibrium with
the aquifer rock and have had a longer residence time within the strata
(Lawrence and Upchurch, 1976). The nonartesian Floridan is unconfined
on top; therefore, higher values for man-induced nitrates are expected
since this represents an area with high agriculture land use; and animal
wastes, septic tank wastes, and chemical fertilizers are easily leached
downward to the Floridan water table. The unconfined Floridan has higher
secondary porosity due to rapid downward percolation of acid rainwater.
This may result in more calcium ions in solution in the nonartesian
The trilinear plot in Figure 16 is a method that can be used to
differentiate the two aquifers, especially the cation balance. In the cation
field, artesian Floridan always displays higher magnesium, sodium, and
potassium, and lower calcium proportions than nonartesian Floridan
water. Floridan nonartesian water is always confined to the calcium bicar-
bonate water type on the Piper Trilinear Diagram.



The Okefenokee Swamp is the headwaters of the Suwannee and
St. Mary's rivers. The upper Suwannee River watershed above the USGS
gaging station at Ellaville, Florida, including the major tributary subbasins.
(Alapaha and Withlacoochee), is approximately 6970 square miles (Figure
1). The Suwannee River above the Withlacoochee Subbasin in Florida
(excluding the Alapaha and Withlacoochee subbasins) is approximately
855 square miles. Surface water and rainfall stations are shown in Figure
48. Upstream from White Springs, Florida, the Suwannee River is
superimposed on as much as 300 feet of sandy clays, clayey sands,
sandstone, and limestone overlying the Floridan Aquifer. Flow for this
portion of the river is essentially dependent on surface runoff from
tributaries draining the numerous swamps, bays, marshes, flatwoods,
lakes and ponds and seepage from the surficial aquifier. Beginning at
White Springs and continuing downstream, the Suwannee River is incised
into the carbonate rock of the Floridan Aquifer. During times of low river
stage, groundwater inflow from Floridan Aquifer springs and seeps in
the river corridor supplements surface runoff in the reach downstream
from White Springs.
In Hamilton County, mining and processing of phosphate has altered
natural drainage patterns and affected water quality in some Suwannee
River tributaries. The amount of surface area created by mining and
beneficiation of phosphate is on the order of 10 square miles (Miller, et
al., 1978b). Lake Louise in Suwannee County (Figure 49 and Table 6),
about 104 acres in size, is the largest lake in the Upper Suwannee River
Basin in Florida. Most lakes and ponds in the Upper Basin generally cover
less than 20 acres in surface area.
There are 14 known springs of third magnitude (1-10 cfs) or larger
in the study area. Nine of these are in the Suwannee River above the
Withlacoochee Subbasin (Figure 49 and Table 7). Alapaha Rise, a first
magnitude spring (greater than 100 cfs), has the highest discharge. The
measured range is from 294 to 1043 cfs.
Local Floridan Aquifer fluctuations (Figures 28,30, and 32) and stage
fluctuations on the Alapaha River near Jennings, Florida, (Figure 39)
generally correspond. Hydrographs of the Alapaha River near Jennings
and Alapaha Rise are also correlative (Figure 50). The apparent dis-
crepancy or lag time of one month at Alapaha Rise during winter 1977-78
is due to backwater from the Suwannee River. The Alapaha Rise is
approximately 22 miles downstream from the station near Jennings. The
response time between stage fluctuations and well level fluctuations in
a Floridan well approximately 12 miles to the southeast is usually less
than 12 hours. While it has not been shown conclusively, Alapaha Rise