Technica l Publicatio n SJ93-7 

### VOLUM E 1 

## O FTHE LOWERST . JOHN S RIVERBASI N RECONNAISSANC E HYDROGEOLOGY b y Davi d J . Toth , Ph.D. , P.G . 

# 0 Professiona l Geologist Licens e No . 11 0 Novembe r18 , 199 3



### Soa l

St . John s Rive

r Water Managemen

t District Palatka , Florid a 199 3

### Northwest Florida Water Management District Suwannee

River Water Management District 

## S t

Rive rWater Management District

St . John s Rive r Wate r Managemen t Distric

t 

### Southwest Florida Water Management District South

Florida Water Management District

Th e St . John s Rive r

Wate r Management

Distric t (SJRWMD ) wa s create d b y th e Florid aLegislature i n 197 2 to b e on e o f

fiv e wate r

managemen t

district s i n Florida . I t

include s al l o r

part o f 1 9 countie s i n northeas t Florida . Th e mission o f

SJRWM D i s to manag e wate r resource s to ensure thei r continue d availabilit

y whil e maximizin g environmenta l an d economi c benefits . I t accomplishe s it s missio n throug h regulation ; applie d research ; assistanc e t o federal , state , an d local governments ; operatio n an d maintenanc e o f wate r contro l works ; an d lan d acquisitio n an d management . Technica l report s are publishe d t o disseminate informatio n collecte d b y SJRWM D i n pursui t o f it s mission . Copie s o f thi s repor t

can b e obtaine d from : Library

St . John s Rive r

Wate r Managemen t

Distric t P.O . Bo x 1429 Palatka , F

L 32178-142

9 Phone : (904 ) 329-413 2Content s



# CONTENT S

Lis t o f Figure s v i Lis t o f Table s viii ABSTRAC T 1 

### INTRODUCTIO

N3 HYDROGEOLOG

Y 9 Limeston e 1 0 Hawthor n Grou p 1 0 Surficia l Deposit s 1 6 AQUIFE RSYSTEM S 2 0 Florida n Aquife r

Syste m2 1 Intermediat e Aquife r

System3 6 Surficia l Aquife r

Syste m3 8 SUMMARY 4 4 RECOMMENDATION S 4 8 Reference s 4 9

St. Johns River

Water Management

District VHYDROGEOLOG Y 

# FIGURE S 1 Majo r surfac e wate r

basin s withi n th e St . John s River Wate r Managemen t

Distric t 4 2 Lowe r

St . John s River

surfac e wate r

basi n 5 1. 1 Th e lower

St . John s Rive r

groun d wate r

flo w syste man d th e lower St . John s River

surfac e wate r

basi n 8 

### 1. 2 Typical hydrostratigraphi c colum n i n th e lowe r

St . John s Rive r groun d wate r

flo w system1 2 1. 3 Cros s sectio n showin g geologi c structur e i n th e lower St . John s Rive r

groun d wate r

flo w syste m1 3 1. 4 Locatio n of

cross-sectio n A-A ' 1 4 1. 5 Dept

h to th e to p o f

th e limestone s o f

th e Floridan aquife r syste mi n th e lower

St . John s Rive r

groun d wate r

flo w syste m1 5 1. 6 Thicknes s o f

th e Hawthor n Grou p i n th e lower St . John s Rive r groun d wate r

flo w syste m1 7 1. 7 Thicknes s o f

surficia l deposit s i n th e lowe r St . John s River groun d wate r

flo w syste m1 8 1. 8 Directio n o f

flo w in the Florida

n aquife r systemo f

the lowe r St . John s Rive r

groun d wate r

flo w syste m2 3 1. 9 Area s o f

natura l recharg e an d discharg e o f the Florida

n aquife r syste mi n th e lowe r

St . John s River

groun d wate r flo w syste man dth e lowe r St . John s Rive r

surfac e wate r basi n 2 5 1.1 0 Majo r

spring s i n th e lowe r

St . John s Rive r

groun d wate r

flo w syste m2 7

St. Johns River

Water Management

District mFigure s 1.1 1 Chlorid e concentration s i n th e Uppe r Floridan aquife r

o f th e lowe r St . John s River

groun dwate r

flo w syste m3 0 1.1 2 Locatio n o f

possibl e fault s i n th e lowe r St . John s Rive r groun d wate r

flo w syste m3 2 1.1 3 Sulfat e concentration s i n th e Uppe r Floridan aquife r

o f th e lowe r St . John s Rive r

groun dwate r

flo w syste m3 4 1.14 Tota l dissolve d solid s i n th e Upper Floridan aquife r

o f th e lowe r St . John s River

groun dwate r

flo w syste m3 5 1.1 5 Directio n o f

flo w i n the surficial aquife r systemo f

the lowe r St . John s Rive r

groun dwate r

flo w syste m4 1 1.1 6 Chlorid e concentration s i n th e uppe r 5 0 fee t o f th e surficia l aquife r syste mi n th e lower

St . John s Rive r

groun dwate r flo w syste m4 3

St . Johns River

Water Management

District viiHYDROGEOLOG Y 

# TABLE S 1 Geologi c tim e scal e 9

2 Hydrogeologi c framewor k o f th e lowe r

St . John s Rive r groun d wate r

flo w system1 1 3 Sourc e o f

wate r use d fo r publi c suppl y an ddomesti c self

suppl y i n th e lowe r

St . John s River

surfac e wate r

basi n . . 2 1

St. Johns River

Water Management

District VliiAbstract 

# ABSTRAC T

Thi s repor

t i s Volume 1 i n aserie s o f reconnaissanc e report s abou t th e Lowe r

St . John s Rive r

Basi n (LSJRB) . Th e lower St . John s River

i s th e norther n par t

o f th e St . John s Rive r

fro mth e mouth o f th e Ocklawah aRiver

i n Putna mCounty t o th e inle t at th e Atlanti c Ocea

n i n Duva l County . LSJR B include s part s o f nin e countie s i n northeas t Florida . Th e reconnaissanc e report s compil e informatio n an dmak e recommendation s t o hel p resourc e manager s identif

y priorit y need s fo r

researc h int o an d managemen t

o f LSJRB . Thes e report s are par t o f th e researc h funde dunde r

th e Surfac e Wate r

Improvemen t

an dManagemen t Act of 198 7 (Section s 373.451-4595 , Florida Statutes). Thi s volum e examine s th e relationshi p an dinfluenc e o f th e interconnectio n betwee n th e lowe r St . John s Rive r

an dth e groun d wate r flo w syste massociate dwith th e river . Th e mechanism s o f thi s interconnectio n are sprin g flow , diffus e upwar d leakag e fro m th e Floridan aquife r

system , an dseepag e fro mth e surficia l aquife r system . Groun dwate r

withi n th e lower

St . John s Rive r groun dwate r

flo w syste mreside s i n th e Floridan , intermediate , an dsurficia l aquife r

systems . Groun dwate r

movemen t

withi n th e portio n o f

th e Floridan aquife r syste mtha t

affect s LSJR

B generall y flow s eastward . Near Gree n Cov e Springs , th e Floridan aquife r syste mi s estimate dt o los e 4 6 cubi c fee t

pe r secon d(ft 3 /sec ) t o th e surficia l aquife r system , th e intermediat e aquife r system , th e St . John s River , o r a combinatio n o f

al l thre e a s aresul t

o f sprin g discharg e an d diffus e upwar dleakage . I n souther n Putna mCounty , 8 0 discharge s fro mth e Floridan aquife r syste mt o th e St . John s Rive r a t Croake r Hol e Spring . I n th e Floridan aquife r

system , moderatel y salin e wate r containin g chloride concentration s betwee n 25 0 an d 1,00 0 milligram s pe r

lite r (mg/L ) i s presen t

beneat h par t

o f th e St . John s Rive r

i n Putna mCount y an di n souther n St . John s an d norther n Flagler

counties . St. Johns River Water Management

District 1HYDROGEOLOG Y Th e intermediat e aquife r syste moverlie s th e Floridan aquife r systemi n portion s o f

Duval , St . Johns , Clay , Putnam , an d Flagle r counties . Wate r

i n th e intermediat e aquife r syste mi s derive d locall y eithe r

b y upwar dleakag e fro mth e underlyin g Floridan aquife r syste mo r

b y downwar dleakag e fro mth e overlyin g surficia l aquife r

system . Th e wate r

tabl e i n th e surficia l aquife r syste mgenerall y i s a subdue dreflectio n o f

th e topography . Wate r

flow s awa y fro m ridge s towar dstreams , creeks , th e St . John s River , an dth e coast . Chlorid e concentration s i n th e uppe r 5 0 fee t o f th e surficia l aquife r systemar

e abov e 1,00

0 mg/L withi n 1-

4 mile s o f

the coas t i n Duval , Flagler , an dVolusi acounties .

St . Johns River

Water Management

District 2Introductio n 

# INTRODUCTIO N

Thi s report

i s Volum e 1 i n aserie s o f reconnaissanc e report s abou t th e Lowe r

St . John s Rive r

Basi n (LSJRB) . Thi s compilatio n o f informatio n an drecommendation s provide s resourc e manager s wit h abasi s fo r

identifyin g priorit

y need s fo r

futur e researc h an d action s regardin g LSJRB . Th e reconnaissanc e report s are par t o f th e researc h funde dunde r th e Surfac e Wate r

Improvemen t

an d Managemen t

(SWIM ) Ac t

o f 198 7 (Section s 373.451-4595 , Florida Statutes'). Th e SWI M Ac t declare s tha t

man y natura l surfac e wate r system s i n Florid ahav e bee n o r

ar e i n dange r

o f becomin g degrade dfro m poin t an dnonpoin t

source s o f

pollutio n an dfro mth e destructio n o f natura l systems . Th e state' s fiv e wate r managemen t

districts , i n cooperatio n wit

h state agencie s an d loca

l governments , were directe dt o se t

prioritie s fo r

waterbodie s o f

regiona l o r

statewid e significanc e an dt o desig n plan s fo r surfac e wate r

improvemen t an dmanagement . Si x waterbodie s wer e name dfo r immediat e action , includin g LSJRB . LSJR B i s on e o f

te n surfac e wate r

basin s o f th e St . John s Rive r Wate r Managemen t

Distric t (SJRWMD ) (Figur e 1) . LSJR B i s locate di n northeas t

Florid aan drepresent s abou t 2 2 percen t

o f th e are awithi n th e boundarie s o f SJRWMD . LSJR

B extend s fro m th e Cit y o f D e Land , i n th e south , t o th e inle t o f th e St . John s Rive r at th e Atlanti c Ocean . LSJR B include s part s o f

nin e counties : Clay , Duval , Flagler , Putnam , St . Johns , Volusia , Alachua , Baker , an dBradfor d(Figur e 2) . Th e climat e o f

LSJR B i s classifie da s humi dsubtropical , wit h an averag e summe r

maximu mdail y temperatur e o f 32. 2 degree s Centigrad e (°C ) (9 0 degree s Fahrenheit) . I n th e winter , LSJR B experience s below-freezin g temperature s a n averag e o f

1 0 t o 1 5 time s pe r year . Averag e annua l rainfal l i n LSJR B i s approximatel y 13 2 centimeter s (5 2 inches) . A larg e portio n o f th e annua l precipitatio n fall s betwee n Jun e an dSeptember whe n convectiv e activity generate s shower s an dthunderstorms . St . Johns River

Water Management

District 38300 W

3 0 0 0 N BASIN S 1 . Nassa u Rive r 2 . St . Marys Rive r 3 . Lowe rSt . John s Rive r 4 . Middl e St . John s Rive r 5 . Lak e Georg e 6 . Uppe rSt . John s Rive r 7 . Ocklawah a Rive r 8 . Florid a Ridg e an d Orang e Lak

e 9 . Uppe rCoasta l 10 . India n Rive rLagoo n

2900 N

Legen d Count y boundar

y Surfac e wate rbasi n boundar y Distric t boundar

y Waterbod y 

### aer 

### k. J INDIA N RIVE R \

1 0 8000 W

ST . JOHN S RIVE R WATE R MANAGEMEN T DISTRIC T 1 6 3 2 J Approximat e scal e i n mile s Figur e 1 . Majo rsurfac e wate rbasin s withi n th e St . John s

Rive rWate rManagemen t DistrictLowe rSt . John s Rive r surfac e wate rbasi n boundar y

Approximat e scal e i n miles Figure 2 . Lowe r St . John s Rive r surfac e wate r basi nHYDROGEOLOG Y Landscap e feature s withi n LSJR B are relativel y lo w an dflat . Thre e ridg e system s borde r th e drainag e area . Surfac e elevation s rang e fro mse aleve l a

t th e inlet to greater

tha n 6 1 meter s (m) (20 0 fee t [ft] ) i n th e western par t

o f LSJRB . Th e St . John s River

i s an elongated , shallo w estuar y wit h an extensiv e floodplain . Th e elevatio n o f th e St . John s Rive r

a t th e mouth o f th e Ocklawah aRive r

i s les s tha n 3. 0 m(1 0 ft ) abov e se a level , an dth e averag e gradien t o f th e mai n rive r

channe l i s onl y 0.02 2 meter s pe r

kilomete r

(0. 1 f t pe r mile) . Averag e annua l tida l amplitud e i s 1. 5 m(4. 9 ft ) a t th e ocea n inle t an dvarie s unequall y upstrea mdu e t o channe l morphology . Du e t o th e lo w gradien t o f th e river , however , tide s affec t th e entir e LSJR

B alon g with th e lowe r reache s o f

it s tributaries . Th e mixin g o f salt wate r an d fres h wate r

ha s a n influenc e o n wate r quality a s wel l a s o n th e quantity an dcharacteristic s o f sediment s deposite d i n LSJRB . Wate r quality condition s fo r

LSJR B rang e fro mgoo di n th e sparsel y populate d souther n en d o f th e basi n to poo r

i n th e urban reache s o f

Jacksonvill e (Han dan dPauli c 1992) . Th e Lower

St. Johns River

Basin reconnaissance report provide s a synthesi s o f

wha t i s know n abou t

th e conditio n o f

th e lowe r St . John s Rive r

an dit s tributarie s fro mthre e perspectives : hydrologic , environmental , an dsocioeconomic . Volum e 1 , Hydrogeology, present s informatio n o n th e groun dwate r flo w syste mi n th e basi n an dit s connectio n t o surfac e waterbodies . Volum e 2 , Surface water

hydrology, discusse s th e surfac e wate r system , includin g hydrologi c an dhydrauli c dat acollectio n networks . Volume 3 , Hydrodynamics an d salinity o f surface water, describe s relationship s betwee n rive r wate r levels , velocity , flow , storage , an d salinit

y an d review s previou s hydrodynami c modelin g studies . Volum e 4 , Surface water quality, an dVolum e 5 , Sediment characteristics an d

quality, presen t

detail s o n th e level s an dtrend s o f

chemical contaminant s presen t i n th e wate r

column an di n th e botto msediments . Volum e 6 , Biological resources, describe s plan t

communitie s an dfish , shellfish , an dmarin e anima l communities . Volum e 7 , Population, land use, an d water use, tie s populatio n estimate s an dprojection s t o lan dus e an d residential , commercial , industrial , an dagricultura l wate r use .

St . Johns River

Water Management

District 6Introductio n Volum e 8 , Economic values, discusse s th e commercial , recreational , an daestheti c value s o f

th e river . Finally , Volum e 9 , Intergovernmental

management, discusse s jurisdictiona l boundaries , regulator y authorities , an dmanagemen t effort s o f

governmenta

l agencies , offices , an dcommission s involve di n restoratio n o r protectio n o f

wate r qualit y an dhabitat . Thi s volume , Hydrogeology, examine s th e relationshi p an d influenc e o f

th e interconnectio n betwee n th e lower St . John s Rive r an dth e groun dwate r

flo w syste massociate dwith th e river . Differen t boundarie s delineate th e groun dwate r flo w systeman d th e surfac e wate r

basi n o f th e lower St . John s Rive r

(Figure 1.1) . Unde r steady-stat

e conditions , groun dwater doe s no t flo w acros s th e groun dwate r

flo w syste mboundary . Th e majo r differences betwee n th e boundarie s o f th e surfac e wate r

basi n an dth e groun dwate r

flo w syste mar e i n thei r

eastern an dsouther n boundaries . Mino r

difference s als o occu r

i n th e norther n an d western boundaries . Th e lower St . John s Rive r

groun dwate r flo w syste munderlie s al l o f St . John s County , mos t

o f Flagler , Clay , Duval , an d Putnamcounties , an d th e northwester n corner o f Volusi aCounty . Th e lowe r St . John s Rive r

surfac e wate r basin , fo r comparison , doe s no t

includ e easter

n St . John s an d Flagle r countie s o r

southwester n an dsoutheaster n Putna m County bu t

doe s includ e aportio n o f north-centra l Volusi a County . Discussion s i n thi s volum e onl y pertai n t o th e groun d wate r flo w system . However , fo r completeness , mos t

o f th e graphics cove r

both th e surfac e wate r

basi n an dth e groun dwate r flo w syste mareas . Informatio n abou t

th e interconnectio n betwee n th e groun dwate r an dth e surfac e wate r

system s wil l b e use di n th e development o f ahydrodynami c mode l fo r th e St . John s Rive r

(volum e 3 o f

thi s reconnaissanc e series) . Th e mode l wil l addres s suc h factor s a s th e effec t o f surfac e an dgroun dwate r discharge s o n th e salinit y o f th e rive r an dth e fat e o f

nutrient s an dpollutant s i n th e river .

St . Johns River

Water Management

District 73 0 DO N

—2930 N Legen d

Lowe rSt . John s Rive rsurfac e wate rbasi n boundar

y am^^

Lowe rSt . John s Rive rgroun d wate rflo w syste m boundar y >NNNNN\N\NNN\\NNN\NNNNNN N

Lowe rSt . John s Rive rgroun d wate rflo w syste m inferre d boundar y Peninsula rdivid e Count y boundar

y Waterbod y Lake *?.'"' • * . • % George

Lowe rSt . John s Rive r groun d wate rflo w syste m 

# V i » : - , \ / ; : . * 

# V la , \J -\ f ,BW . 

# \ i >

1 0 2 0 Approximat e scal e i n mile s Figur e 1. 1 Th e lowe r St . John s Rive r groun d wate r flo w syste m an d th e lowe r St . John s Rive r surfac e wate r basi nHydrogeolog y 

# HYDROGEOLOG Y

Geolog y i n LSJRB ha s bee n discusse di n report s b y Verno n (1951) , Wyric k (I960) , Berme s et

al . (1963) , Clar

k et al . (1964) , Lev e (1966) , Navo y an dBradne r (1987) , Snel

l an dAnderso n (1970) , Spechle r an dHampso n (1984) , an dTot h (1990) . I n general , severa l thousan dfee t

o f sediment overli e th e basement

comple x o f granit e an dothe r

crystallin e rock s (Cederstro me t al . 1979 , p . 5) . Th e hydrogeologi c framewor k o f th e lower

St . John s Rive r groun dwate r

flo w systemconsist s o f

thre e aquife r

systems : th e Floridan , intermediate , an dsurficial . Th e Floridan aquife r syste m consist s o f

limeston e formation s fro mth e Paleocen e an dEocen e epoch s (Tabl e 1) . Th e intermediat e aquife r syste mconsist s o f Tabl e 1 . Geologi c tim e scal e

Perio d Quarterl y Tertiary Epoc h

Holocen e Pleistocen e Pliocen e Miocen e Oligocen e Eocen e Paleocen e Tim e

(i n rnltor t y$a*8 ) 0.0 1 1. 6 5. 3 23. 7 36. 6 57. 8 66. 4 Miocen e deposit s o f

th e Hawthor n Grou p an dundifferentiate d post-Hawthorn Grou p sediments . Th e surficia l aquife r syste m consist s o f

late an dpost-Miocen e surficial deposits .

St. Johns River

Water Management

District 9HYDROGEOLOG Y 

## LIMESTONE Limeston e formation s fro mth e Paleocen e an dEocen e epoch s

for mpar t o f th e principa l artesia n aquifer—th e Floridan aquife r system , whic h i s th e majo r sourc e o f

water i n northern Florida . Th e formation s o f

th e Floridan aquife r

syste minclude , i n orde r

o f increasin g age , th e Ocala , Avo n Park , Oldsmar , an dth e uppe r par t o f th e Ceda r Key s limestone s (Tabl e 2 an dFigure 1.2) . Th e formation s tha t

compris e th e Floridan aquife r syste m typicall y var y i n dept h an dthicknes s throughou t th e groun d wate r flo w syste m(Figure s 1. 3 an d1.4) . Miller (1986) mappe d th e thicknes s an dexten t

o f th e Floridan aquife r

syste mi n Florid a an di n part s o f

Georgia , Alabama , an dSout h Carolina . I n norther n Florida , th e limeston e formation s o f th e Floridan aquife r syste mdi p an dthicke n t o th e northeas t (Figure 1.5) . I n easter n Flagler County , th e depth t o th e to p o f th e Florida n aquife r syste mi s nearl y 10 0 f

t belo w th e Nationa l Geodeti c Vertical Datu m(NGVD) . Th e depth t o th e to p increase s t o 20 0 f t belo w NGV D i n centra l St . John s County an dreache s amaximu mdepth o f mor e tha n 60 0 f

t belo w NGV D i n Duva l Count y near th e St . John s River . Throughou t mos t o f Duval County , th e dept

h to th e to p o f th e Florida n aquife r

syste mrange s fro m30 0 f t belo w NGV D i n th e wester n an dsouther n par t o f th e count y t o 60 0 f

t i n th e cente r o f th e county . 

# HAWTHOR N GROU P

Eocen e rock s ar e overlai n b y rock s o f th e Hawthor n Group . Th e Hawthor n Grou p consist s o f earl y t o middl e Miocen e clay , limestone , an dlayer s o f

interbedde dsan dan dshel l an dserve s a s aconfinin g uni t

tha t separate s th e Florida n aquife r syste mfro m th e overlyin g surficia l aquife r syste m(Tabl e 2 an dFigure 1.2) . Th e intermediat e aquife r syste mconsist s o f

th e Hawthor n Grou p an dundifferentiate dpost-Hawthor n Grou p sediments . Th e Hawthor n Grou p i s absen t fro mmuc h o f

Volusi aCounty an d southeaster n Flagler

an dPutna mcountie s bu t thicken s t o th e northeast , wher e i t

attain s alocalize d maximu mthicknes s o f

St. Johns River

Water Management

District 10Hydrogeolog y

Tabl e 2 . Hydrogeologi c framewor k of th e lowe r St . John s Rive r groun d wate r flo w syste m (modifie d fro m Brow n 1984 an d Berme s et al . 1963 ) Hytfrogeotogt e Uni

t

Surficia l aquife r syste m

Uppe rconfinin g uni t (Intermediat e confinin g unit)

Florida n aquife r syste m Uppe r

water bearin g zon e

Semi confinin g uni t Middl e waterbearin g zon e Semi confinin g uni t Lowe r water bearin g zon e Lowe rconfinin g uni t Stratigraph y Surficia l deposit s

Hawthor n Grou p

Ocal a Limeston e

Avo n Par k Limeston e

Oldsma r Limeston e

Ceda rKey

s Limeston e Approximate

Thicknes s (fas* ) 2 0 t o 17 5

0 t o 50 0

0 t o 35 0

601021 0

50 0 t o 75 0

70 0

Unknow n Li»iOiaS y Discontinuou s sand , clay , an d shel l bed s

Interbedde d phosphati c sand , clay , marl , an d limeston e

Massiv e fossiliferou s chalk y t o granula r marin e limeston e sequenc e Alternatin g bed s o f massiv e granula ran d chalk y limeston e an d dens e dolomite s

Uppermos

t appearance of evaporites ; dens e limeston e Hydragacfogfc Propertie s

San d an d shel l deposit s provid e loca l limite d wate rsupplies . Yield s moderat e t o larg e quantitie s of wate ri n Duva l Count y an d centra l an d easter n Flagle ran d St . John s countie s an d smal l quantitie s of wate r throughou t th e remainde rof th e are a Sand , shell , an d limeston e deposit s provid e local , limite d wate rsupplies , bot h artesia n an d nonartesian . Low-permeabilit y day s serv e a s th e principa l confinin g be d fo rth e Florida n aquife rsyste m below . Importan t sourc e of wate ri n Clay , Duval , an d part s of eastern Flagle ran d St . John s counties Principa l sourc e of groun d water . Hig h permeabilit

y overall . Primar

y water producin g zon e i n Flagler , Putnam , an d St . John s countie s i n th e to p 50-20 0 f t o f th e aquife r

Low-permeabilit

y limeston e an d dolomit e Principa l sourc e o f groun d wate r Low-permeabilit

y limeston e an d dolomit e Highl y permeable ; increase s i n salinit y note d Highl y mineralize d water , ver y lo w permeabilit

y

St . Johns River

Water Management

District 11Lan d surfac e



### ;Hawthor n Group ; Intermediat e aquife rsyste m

"T " 1.' , '.',' , U l_~T'j'J I . 1 ,-J . i .I'M . I.. . 1 7 1 i i i i i i i i i i i i i i i i i ii

t ' i ' ,--L,--l- 1 ' , ',',', ' H-- I --I-I--I- , ' , WAvo n Par k

L i 

### !!Rrid a aquife rsyste m

* ' ' i ' i ' i ' i ' i ' . ' i ' i ' i ! i ' i ' i ' i ' t ' i ' i ' i ' r i i i i i i i i i i i i i i sma r Limestone^ ^ ,',', ' .'.', ' ,',', ' ,',', ' ,',' , i ' i ' i ' i ' i ' Legen d San d Jiii a Sand , shell , an d limeston e Limeston e Figure 1. 2 Typica l hydrostratigraphi c colum n i n th e lowe r

St . John s Rive r groun d wate r flo wsyste m

12U l

C Q L I -t^" I I I I I I r^AVO N PAR KLIMESTONE_ J

1 0 Approximate horizonta l scal e i n mile s 0 26 0 50 0 Approximat e vertica l scal e i n fee t Figur e 1. 3 Cros s sectio n showin g geologi c structur e i n th e lowe r St . John s Rive r groun d wate r flo wsyste m\\N\\\\\\\\\\\\\\XW\X\\X\NNN\\NXNN\\\\\\\\ V

l r agen d Wel l locatio n Cross-sectio n locatio n Lowe rSt . John s Rive rgroun d wate rflo w syste m boundar y Lowe rSt . John s Rive rgroun d wate rflo w syste m inferre d boundar y Peninsula rdivid e County boundar

y County seat Waterbod y

Lowe rSt . John s Rive r groun d wate rflo w syste m

Approximat e scal e i n mile s Figure 1. 4 Locatio n o f cross-sectio n A-A '

1 4Legen d

Waterbod y —200—To p o f Florida n aquife rcontou rlin e

Contou rinterva l = 100 fee t Datu m i s fee t belo w mea n se a leve l (NGV D - 1929 ) Lowe rSt . John s Rive rgroun d wate rflo w syste m boundar y .v\x\\w \ Lowe rSt . John s Rive rgroun d wate rflo w syste m inferre d boundar y Peninsula rdivid e Count y boundar

y

Lowe rSt . John s Rive r groun d wate rflo w syste m

Approximat e scal e i n mile s Figur e 1. 5 Dept h t o th e to p o f th e limestone s o f th e

Florida n aquife r syste m i n th e lowe r St . John s Rive r groun d wate r flo wsyste m

15HYDROGEOLOG Y

mor e tha n 50 0 f

t i n centra l Duva l County near th e St . John s Rive r (Figur e 1.6) . 

## SURFICIAL DEPOSIT S

Th e surficia l aquife r

syste mconsist s o f

deposit s o f

extremel y variabl e litholog y (clay , sand , coquina , limestone ) tha t overli e th e Hawthor n Grou p (Tabl e 2 an dFigure 1.2) . Wher e th e Hawthor n Grou p i s absent , th e surficial material s res t directl y o n th e Eocen e limestone . Th e thicknes s o f surficia l deposit s i n th e lower St . John s River

groun dwate r

flo w systemrange s fro mles s tha n 5 0 f t to mor e tha n 15 0 f

t (Figure 1.7) . I n Duva l County , ayounge r limeston e uni t

occur s at th e bas e o f Pliocen e o r

uppe r Miocen e deposit s an doverlie s th e Hawthor n Group . Thi s limeston e uni t generally consist s o f

asoft , friable , cavernous , sand y limeston e an drange s fro m5 t o 4 0 f t i n thicknes s (Spechler

1982) . Alon g th e coas t

an di n th e souther n par t o f th e county , th e limeston e become s discontinuou s an d grade s int o mediu mt o coars e san dan dshel l deposits . I n western Putna mCounty , th e sediment s tha t overli e th e Hawthor n Grou p ar e non-marin e deposit s tha t consis t o f undifferentiate dbed s o f

coarse , poorl y sorte dsand , kaolin , an d variegate dsand y cla

y (th e Citronell aFormation) . Thes e non marin e bed s are discontinuou s an d canno t b e differentiate d lithologicall y fo r

an y grea t

distanc e (Berme s e t

al . 1963) . Th e sediment s tha t

blanke t th e surfac e i n th e lowe r

St . John s Rive r groun dwate r

flo w syste mar e fro mth e Pleistocen e an d Holocen e epoch s (se e Tabl e 1) . Th e Pleistocen e deposit s consis t o f fin e t o mediu mquart z san dan dthi n lense s o f cla y an dshel l i n th e easter n par t o f th e are aan dfin e to coars e poorl y sorte d san d an dsand y clay i n th e western part . Alon g th e coastal island s an d inlan dfo r approximatel y 3-1 0 miles , th e Anastasi aFormatio n o f th e Pleistocen e Epoc h occurs . Th e Anastasi aFormatio n primaril y consist s o f

shel l bed s tha t

contai n varyin g amount s o f quart z sand , silt , an d organi c material . Th e formatio n extend s more tha n 15 0 mile s sout

h o f St . Augustin e bu t

rarel y extend s inlan d

St. Johns River

Water Management

District 16•\NVVV\N\NVVSVSV\\\X\V\V\NV\\V\NNNSS\SSNXX V

Legen d Count y boundar

y sS\\\\\\\\\\\\\\\\x\\\\w s Lowe rSt . John s Rive rgroun d wate rflo w syste m boundar y Lowe rSt . John s Rive rgroun d wate rflo w syste m inferre d boundar y Peninsula rdivid e Waterbod y ioo —Equa l thicknes s contou rlin e Contou rinterva l = 100 fee t

Lowe rSt . John s Rive r groun d wate rflo w syste m

Approximat e scal e i n mile s Figure 1. 6 Thicknes s o f th e Hawthor n Grou p i n th e lowe r

St . John s Rive r groun d wate r flo wsyste m

178 2 SO W 8 2 0 0 W,. 1 NASSA U 8100 W

3030 N

>XNNXNNX\\X\\\\\\\X\X\\\N\XXX\\XX\\\XXXXX\\\ \

3 0 DO N

—2 9 SO N Legen d TM TM «»»»» » County boundar y •amiini i Lowe rSt . John s Rive rgroun d

wate rflo w syste m boundar y \xxxxxxx - Lowe rSt . John s Rive rgroun d

wate rflo w syste m inferre d boundar y

—^ Peninsula rdivid e "^•'^iil ! Waterbod y

Equa l thickness contou rlin e Contou rinterva l = 5 0 fee t

Lowe rSt . John s Rive r groun d wate rflo w syste m j V S VOLUSI A

' V ^ VHftttff f , fV » \ * S 1 0 2 0 I i I Approximat e scal e i n mile s Figure 1. 7 Thicknes s o f surficia l deposit s i n th e lowe r

St . John s Rive r groun d wate r flo wsyste m

18Hydrogeolog y 

### beyon dth e Intracoasta l Waterway . Highl y variabl e an d undifferentiate dHolocen e sediment s cove r th e Pleistocen e deposits .

St . Johns River Water Management

District 19HYDROGEOLOG Y 

# AQUIFE RSYSTEM S

Aquifer s withi n th e lowe r St . John s River

groun dwate r

flo w syste mbelon g t o th e Floridan aquife r system , th e intermediat e aquife r system , o r

th e surficia l aquife r

system . Eac h aquife r syste mha s adifferen t

influenc e o n rive r

flow . Th e Floridan aquife r syste mcontribute s t o river flo w directl y throug h sprin g discharg e an dindirectl y throug h diffus e upwar dleakage . Th e intermediat e aquife r

syste mindirectl y contribute s t o rive r flo w throug h diffus e upwar dleakage . Th e surficia l aquife r systemcan discharg e directl y int o th e river . Unlik e th e Floridan an d intermediat e aquife r

systems , th e surficia l aquife r syste mi s areall y i n direc t

contac t with th e river . Th e Florida

n aquife r systemi s th e principa

l artesia n aquife r i n nort h Florid aan di s th e on e mos t frequentl y tappe dfo r

wate r supply . I t

i s tappe dfo r

both publi c suppl y an ddomesti c self

suppl y i n Duval , St . Johns , Clay , Putnam , Flagler , an dVolusi a countie s (Tabl e 3) . Beside s publi c an ddomesti c self-supply , th e Florida n aquife r als o i s use dfo r

commercial/industrial self

supply , agricultura l irrigation , self-supplie dpowe r generation , uncontrolle dfree-flowin g (abandone dartesian ) wells , an dheatin g an dcoolin g hea t

pum p units . Intermediate aquifer s occur withi n th e Hawthor n Grou p o r undifferentiate dpost-Hawthor n sediment s an dcontai n limite d quantitie s o f

potabl e water . Man y domesti c wate r suppl y well s i n Duval , Clay , Flagler , an dSt . John s countie s ta p thi s source . I n Flagler County , th e intermediat e aquife r syste mi s als o tappe dfo r publi c supply . Th e surficial aquife r

systemi s les s extensiv e tha n th e Florida n aquife r syste man di s tappe dwhe n th e Florida n aquife r syste m contain s nonpotabl e wate r o r whe n th e Floridan aquife r syste mi s generall y deepe r

tha n 20 0 ft . Th e surficia l aquife r syste mi s tappe da s adomesti c sourc e o f wate r i n Duval , St . Johns , Putnam , Flagler , an d Volusi acountie s an d a s apubli c suppl y sourc e i n St . John s County . St. Johns River

Water Management

District 20Aquife rSystem s

Tabl e 3 . Sourc e o f wate r use d fo r publi c suppl y an d domesti c

self-suppl y i n th e lowe r St . John s Rive r surfac e wate r basi n Count y Duva l St . John s Cla y Putna m Flagle r Volusi a Publi c Supply

Florida n aquife rsyste m Florida n aquife ran d surficia l aquife rsystem s Florida n aquife rsyste m Florida n aquife rsyste m Florida n aquife ran d intermediat e aquife rsystem s Florida n aquife rsyste m Domesli c SeS-suppt y Florida n aquifer , intermediat e aquifer , an d surficia l aquife r system s Florida n aquifer , intermediat e aquifer , an d surficia l aquife r system s Florida n aquife ran d intermediat e aquife rsystem s Florida n aquife ran d surficia l aquife rsystem s Florida n aquifer , intermediat e aquifer , an d surficia l aquife r system s Florida n aquife ran d surficia l aquife rsystem s 

# FLORIDA N AQUIFE RSYSTEM

I n LSJRB , th e Florida n aquife r syste mi s compose do f

an Uppe r Florida n aquife r

an daLowe r

Floridan aquife r

separate db y th e middl e semiconfinin g uni t (Miller 1986) . Older

an ddeepe r

rock s o f th e Lowe r

Florida n aquife r

ar e no t generall y tappe db y well s i n th e stud y are abecaus e sufficien t wate r can b e obtaine dfro m th e overlyin g formation s an dbecaus e th e wate r fro mdeepe r rock s i s generall y mor e saline . Th e primary water-bearin g zone s i n th e Florida n aquife r syste m consis t o f porou s limeston e an ddolomite . Massiv e dolomiti c limeston e an ddolomit e bed s generall y yiel dlittl e o r n o wate r an dac t a s confinin g unit s (Brow n 1984) . I n northeaster n Florida , thes e relativel y impermeabl e bed s restric t th e vertical movemen t

St. Johns River

Water Management

District 21HYDROGEOLOG Y

o f wate r throug h th e aquife r

an dseparat e i t

int o thre e relativel y isolate d water-bearin g zone s (see Tabl e 2) . Th e upper water bearin g zon e consist s o f

th e Ocal aLimeston e an dth e uppe r par t o f th e Avo n Park

Limestone . Th e thicknes s o f th e uppe r

water bearin g zon e average s 25 0 f t at For t Georg e Island , whic h i s locate d north o f

th e rive r near th e inle t (Mot z 1987) . Th e middl e water-bearin g zon e occur s i n th e lowe r par t o f th e Avo n Par

k Limeston e an di s 57 5 f

t thic k a t For t Georg e Island . Th e lowe r water-bearin g zon e occur s i n th e lowe r part o f th e Oldsma

r Limeston e an di s approximatel y 10 0 f t thic k a t For t Georg e Islan d (Motz 1987) . Thes e zone s hav e bee n identifie d at Fernandin a Beach , 2 0 mile s nort h o f th e lower

St . John s Rive r

groun d wate r flo w syste mboundar y (Brow n 1984) . N o additiona l information , however , i s availabl e abou t th e thicknes s o f

th e upper , middle , an dlowe r

water-bearin g zone s beneath th e LSJR B boundary . Miller (1986) considere d th e uppe r water-bearin g zon e t o b e par t o f th e Uppe r

Florida n aquifer . Th e discussion s o n th e middl e an d lower

water-bearin g zone s are containe d i n Miller' s (1986 ) discussion o f

th e Lowe

r Florida n aquifer . Wate r withi n th e lowe r

St . John s Rive r

groun d wate r

flo w syste m flow s fro marea s o f

highe r hydrauli c hea d t o area s o f lowe r hydrauli c hea d i n adirectio n tha t i s generall y at

righ t angle s t o th e potentiometri c surfac e contou r line s (Figur

e 1.8) . Th e elevatio n o f

th e potentiometri c surfac e o f th e Florida n aquife r syste mdefine s th e leve l t o whic h groun d wate r wil l ris e i n tightl y case d well s tha t

penetrat e th e aquife r

system . Th e elevatio n o f th e potentiometri c surfac e fluctuate s both seasonall y an d yearly . Wate r withi n th e Florida

n aquife r syste mtha t

affect s th e lower St . John s Rive r

surfac e wate r

basi n generall y flow s eastward . Recharg e Recharg e t o th e Florida n aquife r syste mi s th e additio n o f wate r t o th e Uppe r

Florida n aquife r

fro mth e overlyin g surficia l aquife r or , mor e directly , fro mrainfal l i n area s where th e surficial aquife r i s thi n o r absen t an dth e limestone s o f

th e Floridan aquife r

ar e at o r near lan d surface . Recharg e t o th e Uppe r Floridan aquife r

als o ca n occu r fro mth e underlyin g Lowe r Floridan aquifer . Principal

St. Johns River

Water Management

District 228230 W

30 SO N

3 0 DO N Wi'^W*^*. *

J w . ^ TM 4 , BRADFOR D

2 9 SO N 

## L Legen d Potentiometri c sur l Jontou rinterva l = Satur n i s fee t abo

v

NN\\\\\\

• Directio n o f groun d wate rflo w Count y boundar

y Lowe rSt . John s Rive raroun d wate rflo w syste m boundar y Lowe rSt . John s Rive rgroun d wate rflo w syste m inferre d ooundar y Sprin g locatio n Peninsula rdivid e Waterbod y

Lowe rSt . John s Rive r groun d wate rflo w syste m ic e contou r(Ma

y 1990) , , i mea n se a leve l (NGV D -1929 ) *

Approximat e scal e i n mile s Figur e 1. 8 Directio n o f flo wi n th e Florida n aquife r

syste m of th e lowe r St . John s Rive r groun d wate r flo wsyste m (base d o n potentiometri c surfac e contours )

2 3HYDROGEOLOG Y recharg e area s fo r

th e Florida

n aquife r syste mi n th e lower St . John s River

groun dwate r

flo w syste man dsurfac e wate r basi n occu r i n southwester

n Cla y County , northwester

n an d southeastern Putna mCounty , an dnorthwestern an dwest-central Volusi aCounty (Figure 1.9 ) (Bonio l et al . 1993) . Area s o f recharg e o f

0- 4 or 4- 8 inche s pe

r yea r occu r i n wester n Duva l an d Clay counties , western an dsoutheastern Putna mCounty , northwestern Volusi aCounty , an dcentra l St . John s an dFlagler counties . Th e lak e regio n o f

southwestern Clay an dnorthwestern Putna m countie s i s recognize da s an are awith arelativel y hig h potentia l fo r lake-leve l declin e i n respons e t o lowere dFloridan aquife r potentiometri c level s (Motz an d Heaney 1991,1992) . Thi s interconnectio n i s importan t becaus e thes e lake s ar e par t o f th e Etoni aCree k

chai n o f lake s tha t

discharge s t o atributar y o f th e St . John s River . Discharg e Discharg e fro mth e Floridan aquife r syste mcan b e direc t

(e.g. , well s or springs ) or

discharg e ca

n b e indirec t

or diffus e (e.g. , diffus e upwar dleakag e t o overlyin g aquife r systems) . Generally , discharg e occur s i n th e easter n portio n o f LSJR B (se e Figur e 1.9) . Outside LSJR

B bu t withi n th e lowe

r St . John s River

groun d water flo w system , discharg e occur s off-shor e i n th e Atlanti c Ocean . Paleosinkhole s occur

i n th e St . John s Rive r

near Bloun t Islan d (abou t 8 mile s upstrea mfro mth e mout h o f th e St . John s River ) (Spechler 1993) . Whe n th e elevatio n o f

th e potentiometri c surfac e o f th e Floridan aquife r syste mi s highe r

tha n th e elevatio n o f

th e wate r

tabl e o f th e surficial aquife r

system , wate r

fro mth e Florida

n aquife r syste mwil l lea

k upwar dt o th e intermediat e aquife r an dsurficia l aquife r systems . Whe n th e potentiometri c surfac e o f th e Floridan aquife r syste mi s higher

than lan dsurface , well s drille d int o th e Florida n aquife r

system , unles s cappe do r valved , wil l flo w freel y at lan dsurface . I n th e lower St . John s Rive r

groun dwate r

flo w system , free-flowin g well s can occur i n easter n Duva l an d

St. Johns River

Water Management

District 2 48230 W 8100 W

3030 N

Area s o f recharg e 0- 4 inche s pe ryea r 4- 8 Inche s pe ryea r 8-1 2 inche s pe ryea r 1 2 o rmore inche s pe ryea r

3 0 DO N

2930 N

Lowe rSt . John s Rive rgroun d

Peninsula rdivid e Count y boundar

y

Lowe rSt . John s Rive r groun d wate rflo w syste m 1 1 1 1 1 1 1 Lowe rSt . John s Rive rsurfac e

wate rbasi n boundar

y SS\\XXS N Lowe rSt . John s Rive . .

wate rflo w syste m inferre d boundar y

Approximat e scal e i n mile s Figure 1. 9 Area s o f natura l recharg e an d discharg e o f th e

Florida n aquife r syste m i n th e lowe r St . John s Rive r groun d wate r flo wsyste m an d th e lowe r St . John s Rive r surfac e wate r basi n

2 5HYDROGEOLOG Y Putna mcounties , northeastern Clay County , an d i n both eastern an d western St . John s an d Flagle r counties . Alon g th e coas t

sout h o f St . Augustine , th e elevatio n o f th e potentiometri c surfac e slope s towar d th e southeas t a s aresul t

o f submarin e discharges . Crescen t Beac h Spring , asubmarin e sprin g abou t

2. 5 mile s eas t

o f Crescen t Beac h (Figur

e 1.10) , ha s bee n describe d b y Stringfiel dan d Cooper (1951 , p . 63 ) an d Brook s (1961) . Re d Snappe r Sin k i s locate d abou t

22. 5 mile s eas t o f Crescen t Beac h Spring ; i t

i s situate d i n wate r

abou t 8 8 f t dee p (Rosena u et al . 1977) . Depression s i n th e elevatio n o f th e potentiometri c surfac e generall y indicate discharg e area s fo r th e Florida

n aquife r syste m (se e Figur e 1.8) . Th e depressio n a t Gree n Cov e Spring s i n Clay County i s du e to acombinatio n o f groun d water

withdrawal s fro mdomesti c an d publi c suppl y well s at Gree n Cov e Springs , pumpin g fro mirrigatio n well s jus t sout h o f th e area , an d th e natura l discharg e fro mth e sprin g at Gree n Cov e Spring s (Tot h 1990) . I n thi s area , th e Florida n aquife r syste mlose s approximatel y 4 6 cubi c fee t per second (ft 3 /sec ) to th e surficial aquife r system , th e intermediat e aquife r system , th e river , o r

a combinatio n o f

al l thre e a s aresul t

o f sprin g discharg e an d diffus e upwar d leakag e (Durde n 1991) . A n unknow n par t o f thi s discharg e o f

4 6 ft 3 /se c coul d b e attribute d t o additiona l unconfirme d spring s dischargin g i n th e vicinit y o f Gree n Cov e Springs . A depressio n i n th e elevatio n o f th e potentiometri c surfac e i n souther n Putna mCount y i s probabl y du e t o Floridan aquife r syste mdischarg e a

t Croake r Hol e Sprin g (see Figure 1.8) . Croake r Hol e Sprin g i s arelativel y deep , small-diamete r hol e i n th e botto mo f

th e St . John s River

a t Littl e Lak e George . Littl e Lak e Georg e i s abou t

5- 9 f t dee p excep t

i n th e immediat e vicinity o f Croake r Hole , wher e i t

plunge s t o adepth o f

abou t 4 8 ft . Th e discharg e o f

Croake r Hol e Sprin g wa s abou t

8 0 ft 3 /se c o n Septembe r

17,198 1 (Tibbal s 1990) .

St. Johns River

Water Management

District 268230 W 8100 W

3 0 SO N

•3 0 DO N

• 2930 N K>XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX X

Rod Snapper Sink 

### Legen d Count y boundar

y County sea t Lowe rSt . John s Rive rgroun d wate rflo w syste m boundar y Lowe rSt . John s Rive rgroun d wate rflo w syste m inferre d boundar y Peninsula rdivid e Waterbod y Sprin g i,XXXXXXXXVX\XXVX\NXXXXXXN V -r Lake

, ^ George

DeUn d

Lowe rSt . John s Rive r groun d wate rflo w syste m 0

I 1 0 2 0 Approximat e scal e i n mile s Figure 1.1 0 Majo r spring s i n th e lowe r St . John s Rive r

groun d wate r flo wsyste m

2 7HYDROGEOLOG Y Beeche r Springs , Welak aSpring , Satsum aSpring , an d Mu d Sprin g als o occur

i n southern Putna mCounty near th e St . John s Rive r (Figur e 1.10) . Th

e discharg e o f

Beeche r Spring s wa s 9 ftVse c o n Apri l 20 , 1972 (Tibbal s 1990) . Th e discharg e fro m Welak aSpring wa s s o small tha t i s coul dno t

b e measure do n Jun e 8,1972 . Th e discharg e fro mSatsum aSprin g wa s 1 ftVse c o n November

1 3 an d 14,1980 , an d the discharg e fro mMu d Sprin g wa s 2 ftYse c o n Jun e 8,197 2 (Tibbal s 1990) . Al l o f th e previou s sprin g discharge s ar e low-flo w measurement s mad e durin g period s o f

deficien t rainfall ; therefore , th e discharge s probabl y represen t

aminimu mflo w fo r

th e perio d1972-81 . A dail y tota l o f

approximatel y 59. 5 millio n gallon s per da y (mgd)—9 2 ftVsec—o f

Floridan aquife r

syste mwate r

i s discharge dint o th e St . John s Rive r throug h thes e spring s (no t includin g Green Cov e Sprin g an d th e other possibl e spring s i n th e vicinit

y o f Gree n Cov e Springs) . Thi s i s asubstantia l amoun t o f groun d wate r

discharge di n aday . Fo r comparison , th e Cit

y o f Jacksonvill e withdre w an averag e 70.49 mg dfro mth e Floridan aquife r systemin 199

0 for publi c suppl y (Florenc e 1992) . The combine ddischarg e o f

Floridan aquife r

syste mwate r

t o th e St . John s River , however , i s amino r amoun t o f th e tota l surfac e wate r flow . Fo r

comparison , th e mea n tota l discharg e o f th e St . John s Rive r

a t Palatk aan dJacksonvill e i s approximatel y 5,90 0 an d7,30 0 ft 3 /sec , respectivel y (Morri s 1993) . Th e depressio n i n th e elevatio n o f th e potentiometri c surfac e o f th e Florida n aquife r

syste mi n centra l an dwestern Flagler County (see Figur e 1.8 ) i s probabl y cause db y diffus e upwar d leakag e an dpossibl y b y discharg e fro munconfirme dsubmerge dspring s nea r th e southeas t

sid e o f nearb y Crescen

t Lake . Computer modelin g suggest s tha t

th e rat e o f

diffus e upwar dleakag e i n th e are ai s abou t

1 6 ft*/se c (Tibbal s 1981) . Several Floridan aquife r

syste mwell s discharg e wate r t o Etoni a Creek near it s confluenc e with Ric e Creek , atributar y t o th e St . John s River . Thi s groun dwater , abou t 1 7 mgd , i s use dto suppor t operation s o f

apul p an dpape r

mil l tha t withdraw s wate r fro mRic e Cree k

downstrea mo f

th e confluence .

St. Johns River

Water Management

District 28Aquife rSystem s Th e U.S . Geological Surve y i s conductin g astud y t o estimat e th e natura l discharg e an dchemical-constituen t loadin g fro mth e Uppe r Floridan aquife r

t o th e lowe r

St . John s River

i n th e lowe r St . John s Rive r

surfac e wate r

basin . I n addition , SJRWM D i s developin g groun dwate r flo w an dwate r

quality model s t o b e use da s tool s fo r

predictin g change s i n potentiometri c level s an d wate r quality i n respons e t o change s i n rate s o f groun dwate r withdrawals . Thes e model s can b e use dt o predic t change s i n sprin g discharg e i n respons e t o change s i n groun dwate r withdrawals . Qualit y o f Groun dWate r Chloride , sulfate , an dtota l dissolve dsolid s (TDS ) are commo n indicator s o f

th e presenc e o f

saline wate r

i n th e Florida

n aquife r system . Thes e thre e constituent s var y widel y i n concentration s i n th e lower St . John s River

groun dwate r

flo w system , and , i n som e instances , concentration s o f thes e constituent s excee dth e publi c drinkin g wate r

standard s (i.e. , chloride—25 0 milligram s per liter [mg/L] , sulfate—25 0 mg/L , an dTDS—50 0 mg/L) . Moderatel y salin e wate r

(chlorid e an dsulfat e concentration s betwee n 25 0 an d 1,00 0 mg/ L an dTD S concentration s betwee n 50 0 an d 3,000 mg/L ) i n th e Floridan aquife r syste menter s th e overlyin g surfac e wate r

syste mthroug h direc t

discharg e fro mspring s o r throug h diffus e upwar dleakage . Chloride . Chlorid e concentratio n i s aprimar y indicato r o f th e presenc e o f

seawate r i n groun dwater . I n th e lower St . John s Rive r groun dwate r

flo w system , chlorid e concentration s ar e generall y belo w 5 0 mg/ L i n th e northern an d wester n part o f LSJR B bu t increas e t o ove r

1,00 0 mg/ L i n souther n Flagler County (Figur

e 1.11) . Thi s informatio n i s base do n dat acollected fro mwell s les s tha n 1,40

0 f t deep . Th e deepes t

well s sample d (depth s nea

r 1,40 0 ft) are locate di n Duval Count y where chloride concentration s ar e generall y belo w 5 0 mg/L . I n Volusi aCounty , chloride concentration s are belo w 25 0 mg/ L i n th e middl e o f th e county bu t

increas e t o ove r

1,00 0 mg/ L i n both th e eastern an d

St. Johns River

Water Management

District 29

# 1 Gree n Cov e Spring s ^ ;„,»•.<" " stark e

"^BRADFOR D

Legen d Count y boundar

y County sea t Lowe rSt . John s Rive rgroun d wate rflo w syste m boundar y ..\\N\\\X N Lowe rSt . John s Rive rgroun d

wate rflo w syste m inferre d boundar y Waterbod y «_250 —Chlorid e concentratio n contou rlin e (i n mg/L )

Lowe rSt . John s Rive r groun d wate rflo w syste m

Approximat e scal e i n mile s Figure 1.1 1 Chlorid e concentration s i n th e Uppe r

Florida n aquife r o f th e lowe r St . John s Rive r groun d wate r flo w system . Data ar e from 1965 to 1987 for wells less than 1,400 feet deep. 30Aquife rSystem s western portion s o f

th e county (alon g th e Atlanti c coas t an d alon g th e St . John s River) . I n th e Floridan aquife r

system , moderatel y salin e wate r containin g chlorid e concentration s betwee n 25 0 an d1,00 0 mg/ L i s presen t beneath par t

o f th e St . John s Rive r

i n Putna mCounty an d i n souther

n St . John s an d northern Flagle r counties . Discharg e fro mhundred s o f irrigatio n well s i n southern St . John s an dcentra l Flagler

countie s seasonall y lower s th e elevatio n o f th e potentiometri c surfac e i n th e are aan dcause s highl y mineralize d wate r t o mov e upwar dint o th e productio n zone s o f thos e well s (Berme s et

al . 1963) . A s aresult , som e well s tha t

yiel dfres h wate r durin g nonpea k

irrigatio n deman dmonth s yiel d moderatel y salin e wate r

durin g th e crop-growin g season . Are a agricultura l drainag e district s contro l irrigatio n an d stormwate r runof f tha t connect s with th e St . John s River . SJRWM D currentl y i s analyzin g dat atha t

will giv e scientist s a

n ide ao f th e influenc e o f th e quality o f

th e groun dwate r

pumpe dfo r

agricultura l purpose s o n th e surfac e wate r system . Localize darea s wher e chlorid e concentration s ar e abov e 5 0 mg/ L occu r alon g th e coas t

an d nea r th e St . John s Rive

r i n Duval an d norther n St . John s counties . Thes e area s o f highe r chloride s ar e probabl y du e t o upwar dmovemen t o f highe r chlorid e water s tha t exis t a t dept h (Tot h 1990) . Chlorid e concentration s abov e 7,000 mg/ L occur

i n th e Lowe r

Floridan aquife r

at depth s greate r tha n 2,000 f

t belo w mea n se aleve l i n th e coasta l portion s o f northeas t Florid a(Lev e 1983) . Some area s with chlorid e concentration s abov e 5 0 mg/ L occu r near th e north-south fault s mappe db y Mille

r i n 198 2 (Figur e 1.12) , suggestin g tha t

th e fault s may b e th e avenu e fo r

some o f thi s upwar dmovement . Accordin g t

o Mille r (1982) , displacement s o f

between 5 0 and 10 0 f t may occu r

alon g thes e faults . Non e o f th e fault s appear

t o hav e a n effec t

o n groun dwate r

flo w withi n th e Floridan aquife r system , probabl y becaus e permeabilitie s are simila r o n bot h side s o f th e faults . Spechler

(1993 ) speculate dtha t

paleokars t

feature s i n thi s are ama y provid e avenue s fo r thi s upwar dmovement .

St. Johns River

Water Management

District 31\\S\\\\\\\\\\\\NS\\\\\\\\\\\\\\\\\\\\\\N\\ N

~**» ^ Vy%^*v>->** '

!^'-"'^^

Legen d Faul t locatio n Fault' s upwar

d sid e Fault' s downwar d sid e Count y boundar

y Lowe rSt . John s Rive rgrou r wate rflo w syste m boundar y Lowe rSt . John s Rive rgroun d wate rflo w syste m interre d Boundar y Peninsula rdivid e Waterbod y

Lowe rSt . John s Rive r groun d wate rflo w syste m

Approximat e scal e i n mile s Figure 1.1 2 Locatio n o f possibl e fault s i n th e lowe r

St . John s Rive r groun d wate r flo wsyste m Source : Mille r198 2 3 2Aquife rSystem s I n area s o f

th e aquife r

wher e chlorid e concentration s ar e greate r tha n 25 0 mg/L , wate r

als o ha s th e relativ e chemical compositio n o f seawater , connat e water , o r relic t (fossil ) seawater . Connat e wate r refer s t o wate r

o f amarin e o r

non-marin e origi n tha t

ha s bee n ou t o f contac t wit h th e atmospher e fo r

an appreciabl e par t o f geologi c time . I t

i s wate r tha t wa s entrappe di n th e rock s whe n th e rock s wer e deposite da s sediment . Compare dt o seawater , connat e wate r

i s enriche di n calcium , magnesium , an d sulfate . Relic t

seawate r i s wate r that wa s entrappe di n th e rock s durin g apas t

geologi c ag e whe n seawate r inundate dth e Florid a peninsula , suc h a s occurre ddurin g th e Pleistocene Epoch . Relic t seawate r i s simila r i n compositio n t o seawate r an dcan b e distinguishe d fro mi t

only b y isotopi c analysis . Sulfate . Th e Upper

Florida n aquife r contain s sulfat e concentration s whic h var y throughou t th e lowe r

St . John s Rive r groun dwater

flo w system(Figur

e 1.13) . The sourc e o f

sulfat e i n th e Floridan aquife r

syste mi s dissolutio n o f

gypsu man d anhydrite , th e oxidatio n o f iro n sulfides , or

th e mixin g o f

eithe r relic t seawate r o r connat e wate r

with freshe r

water . Th e dissolutio n o f

sulfu r mineral s i s aslo w proces s an dca n increas e th e concentration s o f

sulfat e b y arat e o f

1- 8 mg/ L per

10 0 year s (Tot h 1990) . Sulfat e concentration s are generall y belo w 5 0 mg/ L i n th e western par t

o f th e groun dwate r

flo w syste mbu t

increas e t o abov e 50 0 mg/ L i n souther n an deastern St . John s County an d northeaster n Flagler

County . Thi s informatio n i s base do n dat a collecte dfro mwell s les s tha n 1,40 0 f t deep . Th e deepes t

well s sample d(depth s near

1,40 0 ft ) ar e locate di n Duva l County wher e sulfat e concentration s ar e generall y belo w 25 0 mg/L . Moderatel y salin e wate r

i n th e Floridan aquife r

syste m(sulfat e concentration s betwee n 25 0 an d1,00

0 mg/L ) i s presen t

i n muc h o f

St . Johns , norther n an dsouthwester n Flagler , northeastern Putnam , an d wester n Volusi acounties . Total dissolve dsolids . TD S concentration s i n th e Uppe r Floridan aquife r

als o var y dramaticall y throughou t th e lowe r St . John s Rive r

groun dwate r

flo w syste m(Figur e 1.14) . TD S concentratio n i s th e sumo f al l dissolve d constituent s i n groun d water . I t include s sodium , potassium , calcium , magnesium , St. Johns River

Water Management

District 33<« * ^\^-^f,.^>"



### r ^ *i , BRADFOR D

* <.. > ^ft-.--.-.r. 1 ALACHU A



### Legen d County boundar

y Lowe rSt . John s Rive rgroun d wate rflo w syste m boundar y • Lowe rst . jonn s mye rgrqun a wate rflo w syste m inferre d boundar y Peninsula rdivid e Waterbod y § qua l thicknes s contou rlin e ontou rinterva l = 5 0 fee t

Lowe rSt . John s Rive r groun d wate rflo w syste m

Approximat e scal e i n mile s Figur e 1.1 3 Sulfat e concentration s i n th e Uppe r Florida n

aquife r o f th e lowe r St . John s Rive r groun d wate r flo wsyste m

3 4Qree n Cove Spring s , < | i S I Augustin e iqoo ; 

# L 3T JOHN S yv> w« . FLAOLE R Newnans Gainesvill e • Lake Legen d Count y boundar

y County sea t Lowe rSt . John s Rive rgroun d wate rflo w syste m boundar y \wvsv<. v Lowe rSt . John s Rive rgroun d

wate rflo w syste m inferre d boundar y Peninsula rdivid e Waterbod y Tota l dissolve d solid s contou rlin e (i n mg/L )

Lowe rSt . John s Rive r groun d wate rflo w syste m

Approximat e scal e i n mile s Figure 1.1 4 Tota l dissolve d solid s i n th e Uppe r Florida n

aquife r o f th e lowe r St . John s Rive r groun d wate r flo wsyste m

35HYDROGEOLOG Y chloride , sulfate , bicarbonate , iron , silica , an d other minor component s dissolve di n water . TD S concentration s are generall y belo w 50 0 mg/ L i n th e wester n an dnorthern part

o f th e groun d wate r flo w syste mbu t

increas e t o abov e 5,000 mg/ L i n southeastern St . John s County an dnorthwester n an deastern Volusi aCounty . Thi s informatio n i s base do n dat acollecte dfro m well s les s tha n 1,40

0 f t deep . Th e deepes t

well s (depth s near 1,40 0 ft) ar e locate di n Duval County , where TD S concentration s ar e generall y belo w 50 0 mg/L . Moderatel y salin e wate r containin g TD S concentration s between 50 0 an d 3,00 0 mg/ L in th e Floridan aquife r

syste mi s present

i n southern St . Johns , eastern Putnam , mos t

o f Flagler , easter

n an dwester

n Volusia , an dnortheastern Duva l counties . I n additio n t o measurin g TD S fro mwel l water , TD S an dothe r wate r quality parameter s ca n b e measure dfro msprin g discharge . Fo r example , th e quality o f

groun dwate r

dischargin g fro m Croake r Hol e Sprin g wa s measure di n 1981 . 'Th e temperatur e an d dissolve d solid s concentratio n o f the sprin g water

wer e 23°C an d 1,43 0 mg/L , respectively . Th e temperatur e an d dissolve d solid s concentratio n o f

th e river wate r immediatel y upstream fro mth e sprin g wer e 25° C an d68 0 mg/L , respectively . Th e sprin g wate r

i n Septembe r

wa s colder , mor e mineralized , an d thu s denser

tha n th e rive r

water . Th e denser

sprin g wate r probabl y flowe du p th e sprin g bor e an dmove ddownstrea m alon g th e botto mo f

th e river " (Tibbal s 1990) . Chlorid e an d sulfat e concentration s o f

th e sprin g wate r

wer e 68 0 an d 16 0 mg/L , respectively ; th e chloride an dsulfat e concentration s o f th e upstrea mrive r

wate r wer e 28 0 an d8 4 mg/L , respectivel y (Tibbal s 1990) . 

## INTERMEDIAT E AQUIFE RSYSTE M Th e intermediat e aquife r

syste mi s no t

areall y extensive , bu t occur s i n portion s o f

Duval , St . Johns , Clay , Putnam , an dFlagler counties . I t

range s fro mles s tha n 1 0 t o abou t 30 0 f t belo w mean se aleve l an dvarie s i n thicknes s fro mles s tha n 1 t o abou t 1 5 f t (Berme s et

al . 1963) .

St . Johns River

Water Management

District 36Aquife rSystem s Intermediat e aquifer s withi n th e Hawthor n Grou p o r undifferentiate dpost-Hawthor n sediment s are an importan t sourc e o f wate r i n Duval , Clay , an dpart s o f eastern Flagler

an d St . John s counties . Mor e precis e informatio n i s neede dabou t th e geographi c location , depth , an dthicknes s o f th e intermediat e aquife r

system . Mor e informatio n als o i s neede dabou t th e relationshi p o f

th e intermediat e aquife r

syste mwit

h th e overlyin g surfitia l aquife r syste man dth e underlyin g Floridan aquife r system . Recharg e

Discharg e Intermediat e aquifer s ar e recharge dfro ma t leas t tw o differen t sources , dependin g o n potentiometri c pressures . Whe n potentiometri c level s i n th e surficia l aquife r syste mar e greate r tha n thos e i n th e intermediat e aquife r system , th e intermediat e aquife r syste mi s recharge db y downwar dleakag e fro mth e surficia l aquife r

system . Similarly , whe n potentiometri c level s i n th e Florida n aquife r

syste mar e greate r

tha n thos e i n th e overlyin g intermediat e aquife r system , th e intermediat e aquife r syste mi s recharge db y upwar dleakag e fro mth e Floridan aquife r system . Intermediat e aquifer s discharg e t o tw o differen t sources , dependin g o n potentiometri c pressures . Whe n potentiometri c level s i n th e intermediat e aquife r syste mar e greate r

tha n thos e i n th e surficia l aquife r

system , th e intermediat e aquife r syste mlose s wate r b y upwar d leakag e t o th e surficial aquife r system . Whe n potentiometri c level s i n th e intermediat e aquife r syste mar e greate r tha n th e elevatio n o f

th e potentiometri c surfac e o f th e Floridan aquife r

system , th e intermediat e aquife r syste mlose s wate r b y downwar dleakag e t o th e underlyin g Floridan aquife r system .

St . Johns River Water Management

District 3 7HYDROGEOLOG Y

Qualit y o f Ground Wate r Chloride , sulfate , an dTD S are commo n indicator s o f th e presenc e o f salin e wate r

i n th e intermediat e aquife r system . Wher e th e intermediate aquife r

systemcontain s moderatel y saline wate r (chlorid e an d sulfat e concentration s betwee n 25 0 an d 1,00 0 mg/ L an d TD S concentration s betwee n 50 0 an d 3,00 0 mg/L) , th e wate r coul d enter

th e overlyin g surfac e wate r systemthroug h diffus e upwar d leakage . Wate r i n th e intermediate aquife r systemi s derive d locall

y either b y upwar d leakag e fro mth e underlyin g Floridan aquife r syste m o r b y downwar d leakag e fro mth e overlyin g surfitia l aquife r system . Wate r

quality i n th e intermediat e aquife r syste mi s simila r t o th e wate r

quality i n on e o f

th e othe r aquife r system s withi n th e sam e genera l area . I n th e deep intermediat e aquifers , th e quality o f

wate r usuall y i s simila

r t o wate r i n th e underlyin g Floridan aquife r

system , an di n th e shallo w intermediat e aquifer s th e quality o f

wate r usuall y i s simila

r t o wate r i n th e overlyin g surficia l aquife r

syste m(Berme s e t

al . 1963) . Navo y an dBradne r (1987 ) specif

y chlorid e an dTD S concentration s fo r th e intermediat e aquife r

i n Flagle r

County . Chlorid e concentration s range d fro m2 1 t o 1,23 0 mg/L ; TD S concentration s range d fro m 35 6 to 2,01 6 mg/L . Th e higher value s occurre d beneath th e barrie r island . Wes t

o f th e Intracoasta l Waterway , chlorid e an d TD S concentration s wer e les s tha n 20 0 mg/ L an d70 4 mg/L , respectively . Littl e additiona l informatio n ha s bee n publishe d o n th e chloride , sulfate , o r

TD S concentration s o f

th e intermediat e aquife r i n LSJRB . Mor e precis e informatio n abou t th e wate r quality o f th e intermediat e aquife r syste mneed s t o b e collected . 

## SURFICIA L AQUIFE RSYSTEM

Th e surficia l aquife r

syste mi s th e principal sourc e o f potabl e wate r i n St . John s County an dan importan t sourc e o f

domesti c self-suppl y wate r

i n Duva l an dFlagler

counties . I n mos t

o f Duva l County , alimeston e uni t i s th e principa l water-producin g uni t i n th e surficia l aquife r

system . Wate r

i n th e surficia l aquife r syste mgenerall y i s unconfined . I n swamp y lowlan d an d flatlan d

St. Johns River

Water Management

District 38Aquife rSystem s



### areas , th e wate r

tabl e i s generall y at

o r near lan dsurfac e throughou t

mos t o f th e year . Th e genera

l directio n o f

surficial groun dwate r

flo w i s away fro m ridge s (Bergman 1992) . Ridge s occur alon g th e coas t

i n Duval , St . Johns , an dFlagler

countie s an di n southeastern Putna m Count y (Bergman 1992) . Uplands , o r area s o f highe r land , occu

r i n western Clay an dPutna mcounties . I n thes e areas , th e wate r tabl e i s generall y asubdue d reflectio n o f th e topography , bu t

i t can b e 10-3 0 f

t belo w lan dsurface . Mor e precis e informatio n ha s no t bee n documente do r

mappe d regardin g th e distributio n an dthicknes s o f th e surficia l aquife r syste man dabou t

th e wate r level s i n th e surficial aquife r syste m o f th e lowe r

St . John s River

groun dwate r

flo w system . Informatio n regardin g wate r level s i n th e wate r

tabl e o f th e surficia l aquife r

syste mi s particularl y lacking . Al l o f thi s informatio n woul d b e usefu l to suppor t th e development

o f groun dwate r

flo w models . Mode l simulation s can estimat e th e amoun t o f surficia l aquife r

syste mwate r

dischargin g t o th e lowe r St . John s Rive r

surfac e wate r

basin . Recharg e

Discharg e Th e surficia l aquife r syste mi s recharge db y local rainfall , irrigation , som e lakes , ditches , streams , septi c tan k effluent , sewag e o r stormwate r

holdin g pon deffluent , and , i n area s wher e th e elevatio n o f

th e potentiometri c surfac e o f th e Florida

n aquife r syste mi s abov e th e wate r table , upwar dleakag e fro mth e Uppe r Florida n aquifer . Th e surficia

l aquife r systemi s generally recharge da t

th e ridge s an dwate r

move s awa y fro mth e ridge s towar dth e St . John s Rive r an dth e coast . Wate r leave s th e surficia l aquife r syste mb y seepag e t o some lakes , ditches , an d streams ; b y evapotranspiratio n where th e wate r tabl e i s at

o r near lan dsurface ; b y wel l withdrawals ; and , wher e th e elevatio n o f

th e potentiometri c surfac e o f th e Floridan

St. Johns River

Water Management

District 39HYDROGEOLOG Y aquife r syste mi s belo w th e elevatio n o f th e wate r table , b y downward leakag e to th e Florida n aquife r system . N o quantitativ e informatio n i s availabl e o n th e flo w o f wate r fro m th e surficia l aquife r

syste mt o th e St . John s River ; however , wate r generall y flow s towar dstream s an dcreeks , th e St . John s River , an dth e coas t

(Figure 1.15) . I n Duva l County , ther e ar e interconnection s betwee n th e St . John s Rive r an dth e basa l limeston e uni t o f th e surficia l aquife r

system (Spechle r an dSton e 1983) . "Water i n th e limeston e i s movin g towar dan ddischargin g int o th e St . John s River . Mos t o f th e discharg e i s occurrin g alon g th e sout h sid e o f th e rive r wher e th e potentiometri c gradien t

i s steepest " (Spechle

r an dSton e 1983) . Qualit y o f Groun d Wate r Chloride , sulfate , an dTD S are commo n indicator s o f th e presenc e o f salin e wate r

i n th e surficia l aquife r

system . Moderatel y salin e water (chloride an dsulfat e concentration s betwee n 25 0 an d1,00 0 mg/ L an dTD S concentration s betwee n 50 0 an d3,000 mg/L ) i n th e surficia l aquife r

syste menter s th e overlyin g surfac e wate r syste mdirectl y throug h discharg e an dindirectl y throug h diffus e upwar dleakage . Wher e th e surficia l aquife r syste munderlie s surfac e waterbodie s containin g moderatel y saline water , thi s wate r ca n ente r

th e surficia l aquife r

syste mthroug h downwar d leakage . Durin g time s o f excessiv e rain , th e elevatio n o f th e wate r tabl e i n th e surficia l aquife r syste mcan rise , causin g septi c tank s t o malfunction , whic h can resul t i n th e discharg e o f leachate to th e St . John s River . A situatio n suc h a s thi s i s know n t o occur near Palatk ao n th e eas t

side o f th e St . John s River . Wher e wate r

i n th e limeston e i s unconfine di n Duva l County , salin e rive r

wate r ca n mov e naturall y throug h th e overlyin g sediment s an dint o th e limeston e unti l ahydrauli c equilibriu mi s reached . Wher e th e limeston e adjacen t t o th e rive r

i s semiconfine dbu t

th e limeston e i n th e river channe l i s breache d an dwhe n th e stag e o f

th e rive r i s greate r

tha n th e potentiometri c pressur e o f

wate r i n th e limeston e unit , salin e rive r wate r ca n mov e throug h th e breache dsectio n o f th e limestone . Th e locatio n

St. Johns River

Water Management

District 40/ ' '

. / I, -

Leggn d Count y boundar

y Lowe rSt . John s Rive rgroun d wate rflo w syste m boundar y \\vovxx v Lowe rSt . John s Rive rgroun d

wate rflo w syste m inferre d boundar y Peninsula rdivid e Waterbod y Directio n o f groun d wate rflo w

Lowe rSt . John s Rive r groun d wate rflo w syste m

Approximat e scal e i n mile s Figure 1.1 5 Directio n o f flo wi n th e surficia l aquife r

syste m o f th e lowe r St . John s Rive r groun d wate r flo wsyste m

4 1HYDROGEOLOG Y

o f th e 250-mg/

L isochlo r

i s estimate dt o b e les s tha n 1,00 0 f t fro m th e rive r (Spechle r an dSton e 1983) ; chlorid e concentration s increas e a s th e river

i s approached . Mos t o f th e surficia l deposit s i n th e lower St . John s Rive r

groun d water flo w systemar

e greater than 5 0 f t thic k (se e Figure 1.7) . Chlorid e concentration s i n th e uppe r 5 0 f t o f th e surficia l aquife r syste mare generall y belo w 5 0 mg/ L (Figure 1.16) . Chlorid e concentration s i n th e surficia l aquife r syste mgenerall y increas e wit h depth . Chlorid e concentration s are abov e 1,00 0 mg/ L withi n 1- 4 mile s o f

the coas t in Duval , Flagler , and Volusi a counties . Ther e i s no t

adequat e area l coverag e t o prepar e map s o f th e sulfat e o r

ID S concentration s o f

th e uppe r

5 0 f t o f th e surficia l aquife r i n LSJRB . Mor e precis e informatio n abou t th e wate r

quality o f

th e surficia l aquife r syste mneed s t o b e collecte dan ddocumented . There i s a paucit y o f

dat aregardin g change s (permanen t o r seasonal ) i n wate r quality at

depths . Thi s informatio n woul db e usefu l i n mode l simulations , whic h can estimat e th e constituen t loading s o f surficia l aquife r

syste mdischarg e t o th e lowe r St . John s River surfac e wate r

basin .

St . Johns River

Water Management

District 42,100 0 \\N>.\\\\\\\\N\\\\\\X\\\\\\\\\\\\\\\\\\\\\\ V

Legen d Count y boundar

y Count y sea t Lowe rSt . John s Rive rgroun d wate rflo w syste m boundar y ,\\\\\w. > Lowe rSt . John s Rive rgroun d

wate rflo w syste m inferre d boundar y Peninsula rdivid e • \ ~*s» . yVaterbod y Chlorid e concentratio n contou rlin e (i n mg/L )

Lowe rSt . John s Rive r groun d wate rflo w syste m

Approximat e scal e i n mile s Figure 1.1 6 Chlorid e concentration s i n th e uppe r 5 0 fee t

of th e surficia l aquife r syste m i n th e lowe r St . John s Rive r groun d wate r flo wsyste m

4 3HYDROGEOLOG Y 

# SUMMARY

Thi s volum e examine s th e relationshi p an dinfluenc e o f th e interconnectio n betwee n th e lower St . John s Rive r

an dth e groun d wate r flo w systemassociate dwit h th e river . Th e mechanism s o f thi s interconnectio n ar e sprin g flow , diffus e upwar dleakag e fro m th e Floridan aquife r

an dintermediat e aquife r systems , an d seepag e fro mth e surficial aquife r system . Th e geolog y o f

th e lowe r St . John s River

groun d wate r

flo w syste mconsist s o f

several thousan dfee t

o f Paleocen e Epoc h an d younge r age drock s overlyin g abasemen t comple x o f

granit e an d othe r crystallin e rocks . Limeston e formation s dip an d thicke n towar dth e northeas t

i n norther n Florid aan dfor mpar t o f th e principal artesia n aquifer , th e Florida n aquifer . Th e Floridan aquife r syste mi s separate dfro mth e overlyin g surficia l aquife r syste mb y th e intermediat e aquife r system . Th e intermediat e aquife r systemconsist s o f

Miocene deposit s o f

th e Hawthorn Grou p an dundifferentiate dpost-Hawthorn Grou p sediments . Th e Hawthorn Grou p i s absen t over th e southern portio n o f

th e lowe r St . John s Rive r

groun dwate r

flo w system , bu t

thicken s t o th e northeast . Deposit s o f extremel y variabl e litholog y overli e th e Hawthorn Grou p an dfor mpar t o f th e surficial aquife r

system . Th e primar y water-bearin g zone s i n th e Floridan aquife r syste m consis t o f porou s limeston e an d dolomite . Massiv e dolomiti c limeston e an ddolomit e bed s generall y yiel dlittl e o r n o wate r an dac t a s confinin g units . I n northeastern Florida , thes e relativel y impermeabl e bed s restric t th e vertica l movemen t

o f wate r throug h th e aquife r

an dseparat e i t

int o thre e relativel y isolate d water-bearin g zones . Principal recharg e area s fo r th e Floridan aquife r

syste mi n th e lower St . John s Rive r

groun dwate r

flo w syste moccur

i n southwestern Clay County , northwester n an dsoutheastern Putna mCounty , an d northwester n an d west-centra

l Volusi a County .

St . Johns River

Water Management

District 4 4Summar y Wate r withi n th e Florida n aquife r syste mtha t

affect s LSJR

B generall y flow s eastward . Discharg e fro mth e Floridan aquife r syste mca n b e direc t

(e.g. , well s o r

springs ) o r

discharg e ca

n b e indirec t o r diffus e (e.g. , diffus e upwar dleakag e to overlyin g aquife r systems) . Discharg e area s occur alon g th e eastern portio n o f LSJRB . Outside LSJR

B but withi n th e lower

St . John s River groun dwate r

flo w system , discharg e occur s off-shor e i n th e Atlanti c Ocean . Several depression s occur i n th e elevatio n o f

th e potentiometri c surfac e o f th e Florida

n aquife r systemi n th e lowe

r St . John s Rive

r groun dwate r

flo w system . Th e depression s signif y area s wher e wate r i s bein g remove dfro mth e Florida n aquife r systemb y well withdrawals , diffus e upwar dleakage , o r sprin g discharge . Nea r Gree n Cov e Springs , th e Florida n aquife r syste mi s estimate dto los e approximatel y 4 6 ft 3 /se c t o th e surficia l aquife r system , th e intermediat e aquife r

system , th e St . John s River , o r acombinatio n o f al l thre e a s aresul t

o f sprin g discharg e an ddiffus e upwar d leakage . I n souther n Putna mCounty , 8 0 ft 3 /se c discharge s fro m th e Florida

n aquife r systemto th e St . John s Rive r a t Croaker Hole Spring . I n th e Floridan aquife r

system , chlorid e concentration s ar e generall y belo w 5 0 mg/ L i n th e norther n an dwestern par t o f th e lowe r St . John s River

groun dwate r

flo w systembu t

increas e to ove r 1,00 0 mg/ L i n southern Flagler County . I n th e Floridan aquife r system , moderatel y saline water containin g chloride concentration s betwee n 25 0 an d1,00 0 mg/ L i s presen t

beneath par t o f th e St . John s Rive r

i n Putna mCount

y an di n southern St . John s an dnorther n Flagler counties . I n Volusi aCounty , chlorid e concentration s ar e belo w 25 0 mg/ L i n th e middl e o f th e county bu t

increas e to ove

r 1,00 0 mg/ L i n bot

h th e easter

n an d western portion s o f

th e count y (alon g th e Atlanti c coas t an dth e St . John s River) . Sulfat e concentration s i n th e Florida n aquife r are generall y belo w 5 0 mg/ L i n th e wester n par t o f th e lower

St . John s Rive r

groun d wate r flo w syste mbu t

increas e t o mor e tha n 50 0 mg/ L i n southern an deaster n St . John s County an dnortheaster n Flagler

St. Johns River

Water Management

District 45HYDROGEOLOG Y County . Moderatel y salin e wate r (sulfat e concentration s betwee n 25 0 an d1,00

0 mg/L ) i s presen t

i n muc h o f

St . Johns , norther n an d southwestern Flagler , northeaster n Putnam , an d western Volusi acounties . TD S concentration s i n th e Floridan aquife r are generall y belo w 50 0 mg/ L i n th e western an dnorther n par t o f th e lower

St . John s River groun dwate r

flo w syste mbu t

increas e t o abov e 5,000 mg/ L i n southeaster n St . John s County an dnorthwestern an deastern Volusi aCounty . Moderatel y salin e wate r (TD S concentration s betwee n 50 0 an d3,00 0 mg/L ) i s presen t

i n southern St . Johns , eastern Putnam , mos t o f Flagler , eastern an d wester n Volusia , an d northeaster n Duval counties . Th e intermediat e aquife r syste mi s no t

areall y extensive , bu t occur s i n portion s o f

Duval , St . Johns , Clay , Putnam , an dFlagler counties . I t

range s fro mles s tha n 1 0 t o abou t 30 0 f t belo w mea n se alevel an d varie s i n thicknes s fro mles s tha n 1 to 1 5 ft . Water i n th e intermediat e aquife r syste mi s derive dlocall y eithe r b y upwar dleakag e fro mth e underlyin g Floridan aquife r syste mo r b y downwar dleakag e fro mth e overlyin g surficia l aquife r system . Wate r quality i n th e intermediat e aquife r syste mi s simila

r t o th e wate r quality o f

on e o f th e othe r aquife r system s withi n th e sam e genera l area . Th e surficial aquife r

systemi s th e principa

l sourc e o f

potabl e wate r i n St . John s County an dan importan t sourc e o f

domesti c self-suppl y wate r

i n Duva l an dFlagler

counties . Wate r

i n th e surficia l aquife r

i s unconfined , an dth e wate r tabl e i s generall y a subdue dreflectio n o f

th e topography . Th e surficia l aquife r systemi s generall y recharge da t th e ridge s an d water

move s awa y fro mth e ridge s towar dth e St . John s Rive r an dth e coast . Wate r leave s th e surficia l aquife r syste mb y seepag e t o som e lakes , ditches , an dstreams ; b y evapotranspiratio n wher e th e wate r tabl e i s at

o r near lan dsurface ; b y wel l withdrawals ; and , where th e elevatio n o f

th e potentiometri c surfac e o f th e Florida

n aquife r syste mi s belo w th e wate r table , b y downwar dleakag e t o th e Florida n aquife r

system .

St. Johns River

Water Management

District 46Summar y I n th e uppe r

5 0 f t o f th e surficia l aquife r

system , chlorid e concentration s are abov e 1,00 0 mg/ L withi n 1-

4 mile s o f

th e coas t i n Duval , Hagler , an d Volusi acounties . In Duva l County , there i s an interconnectio n betwee n th e surficia l aquife r syste man dth e St . John s River .

St. Johns River Water Management

District 47HYDROGEOLOG Y 

# RECOMMENDATION S

A revie w o f

th e availabl e literatur e indicate s anee dfo r additiona l informatio n abou t

th e relationshi p an dinfluenc e o f th e interconnectio n o f

th e lowe r St . John s River

groun d water

flo w syste mwith th e surfac e wate r basin . Th e followin g activities , therefore , ar e recommended . • Collec t

mor e informatio n o n th e surficia l aquife r system . Thi s informatio n shoul db e use dt o ma p th e distribution , thickness , wate r

levels , an dwate r

qualit y o f th e surficial aquife r system .

• Quantif

y discharg e t o th e St . John s Rive r fro mth e surficia l aquife r system . N o quantitativ e informatio n i s availabl e o n th e flo w o f

wate r fro mth e surficia l aquife r syste mt o th e St . John s River . • Collec t

mor e informatio n o n th e intermediat e aquife r syste m i n orde r t o identif y geographi c location s wher e surfac e wate r ma y b e influence db y th e intermediat e aquife r system . • Continu e t o documen t th e location , flow , an d wate r quality o f submerge dspring s an darea s o f diffus e upwar dleakag e fro mth e Horidan aquife r syste mt o LSJRB . • Coordinat e with local publi c health unit s t o identif y area s i n clos e proximity to th e St . John s Rive r where there are hig h concentration s o f

septi c tanks . A determinatio n shoul db e mad e concernin g th e potentia l fo r thes e septi c tank s t o malfunctio n an ddischarg e undesirabl e quantitie s an d concentration s o f

leachat e t o th e surficia l aquife r syste man d th e St . John s Rive r

durin g period s o f

excessiv e rain .

St . Johns River

Water Management

District 48Reference s 

# REFERENCE S

Bergman , M.J . 1992 . Volume 2 o f th e Lower St . Johns River

Basin reconnaissance: Surface water hydrology. Technical Publicatio n SJ92-1 . Palatka , Ha. : St . John s Rive r Wate r Management District . Bermes , B.J. , G.W . Leve , an dG.R . Tarver . 1963 . Geology an d ground water resources ofFlagler, Putnam, and St. Johns counties, Florida. Report

o f Investigation s No . 32 . Tallahassee , Ha. : Horid aGeological Survey . Boniol , D. , M . Williams , an dD . Munch . 1993 . Mapping recharge to the Floridan aquifer

using a geographic information system. Technical Publicatio n SJ93-5 . Palatka , Ha. : St . John s Rive r Wate r Managemen t

District . Brooks , H.K . 1961 . Th e submarin e sprin g of f Crescen t Beach , Horida . Quart. Jour. Fla. Acad. Sci. 24(2):122-134 . Brown , D.P . 1984 . Impact o f development

o n availability an d

quality of ground water in eastern Nassau County, Florida, and southeastern Camden County, Georgia. Wate r Resource s Investigation s Report

83-4190 . Tallahassee , Ha. : U.S . Geological Survey . Cederstrom , D.J. , E.H . Boswell , an dG.R . Tarver . 1979 . Summary appraisals of

the nation's ground

water resource - South Atlantic Gulf Region. Professiona

l Paper 813-0. Washington , D.C. : U.S . Geological Survey . Clark , W.E. , R.H . Musgrove , C.G . Menke , an dJ.W . Cagle , Jr . 1964 . Water

resources o

f Alachua, Bradford, Clay, an d Union counties, Florida. Repor t

o f Investigation s No . 35 . Tallahassee , Ha. : Horid aGeological Survey . Durden , D.W . 1991 . Computer simulation o

f th e predevelopment

an d current Floridan aquifer

system i n northeast

Florida. Technical

St. Johns River

Water Management

District 49HYDROGEOLOG Y Publicatio n SJ91-4 . Palatka , Fla. : St . John s Rive r Wate r Managemen t

District . Florence , B.L . 1992 . Annual water us e survey: 1990. Technica l Publicatio n SJ92-4 . Palatka , Fla. : St . John s River Wate r Managemen t

District . Hand , J. , an dM . Paulic . 1992 . 1992 Florida water quality assessment 305(b) technical

appendix. Burea

u o f Surfac e Wate r Management . Tallahassee , Fla. : Florid aDepartmen t o f Environmental Regulation . Leve , G.W . 1966 . Ground water i n Duval an d Nassau counties, Florida. Florid aGeological Surve y Repor t o f Investigation s No . 43 . D e Land , Fla. : E.O . Painter Printing .

. 1983 . Relatio n o f

conceale dfault s t o wate r quality an d th e formatio n o f

solutio n feature s i n th e Floridan aquifer , northeaster n Florida , U.S.A . Journal o f Hydrology 61:251-264 . Miller , J.A . 1982 . Geology an d configuration o

f th e to p o f th e Tertiary limestone aquifer

system, southeastern United States. Ope n File Repor t 81-1178 . Atlanta , Ga. : U.S . Geological Survey .



### . 1986 . Hydrologic frameworks o f th e Floridan aquifer

system in Florida and

in parts of

Georgia, Alabama, and

South Carolina. Professiona l Pape r

1403-B . Washington , D.C. : U.S . Geologica l Survey . Morris , F.W . 1993 , draft . Volume 3 o f th e Lower St . Johns River Basin reconnaissance: Hydrodynamics and salinity of

surface water. Palatka , Fla. : St . John s River Wate r Managemen t District . Motz , L.H . 1987 . Sourc e ter mequation s an dsolut e transpor t mode l fo r consumptiv e us e permi t

application . I n Proceedings o

f th e NWW A conference an d exposition o n solving

St. Johns River

Water Management

District 50Reference s ground water problems with models, Vol . 1 . Dublin , Ohio : National Wate r

Well Association . Motz , L.H. , an d J.P . Heaney . 1991 . Upper Etonia Creek

hydrologic study: Phase I

: Final report. Specia

l Publicatio n SJ91-SP5 . Palatka , Fla. : St . John s Rive r Wate r Managemen t

District .

. 1992 . Upper

Etonia Creek

hydrologic study: Phase II : Final report. Specia

l Publicatio n SJ92-SP18 . Palatka , Fla. : St . John s Rive r Wate r Managemen t

District . Navoy , A.S. , an dL.A . Bradner . 1987 . Ground water resources o

f Flagler County, Florida. Wate r Resource s Investigation s Repor t 87-4021 . Tallahassee , Fla. : U.S . Geologica l Survey . Rosenau , J.C. , G.L . Faulkner , C.W . Hendry , Jr. , an d R.W . Hull . 1977 . Springs o

f Florida. Bulleti n No . 3 1 (revised) . Tallahassee , Fla. : Florid aDepartmen t o f Natura l Resources . Snell , L.J. , an dW . Anderson . 1970 . Water resources o

f northeast Florida. Repor

t o f Investigation s No . 54 . Tallahassee , Fla. : Florid aDepartmen t

o f Natura l Resources . Spechler , R.M . 1982 . Generalized configuration o

f th e to p o f th e limestone unit

of the lower part of the surftcial

aquifer, Duval County, Florida. Open File Report 82-336 . Tallahassee , Fla. : U.S . Geological Survey .

. 1993 , i n press . Saltwater intrusion an d

quality o f water i n th e Floridan aquifer

system, northeast

Florida. Wate r

Resource s Investigation s Repor

t 92-4174 . Tallahassee , Fla. : U.S . Geological Survey . Spechler , R.M. , an d P.S . Hampson . 1984 . Ground water resources o f St. Johns County, Florida. Wate r Resource s Investigation s Repor t 83-4187 . Tallahassee , Fla. : U.S . Geological Survey .

St . Johns River

Water Management

District 51HYDROGEOLOG Y Spechler , R.M. , an d R.B . Stone , Jr . 1983 . Appraisal o f th e interconnection between the St. Johns River and the surficial aquifer, east-central

Duval County, Florida. Wate r Resource s Investigation s Repor t

82-4109 . Tallahassee , Fla. : U.S . Geological Survey . Stringfield , U.T. , an d H.H . Cooper , Jr . 1951 . Geologic an d hydrologic features o

f a n artesian spring east

o f Florida. Repor t o f Investigation s No . 7 , pt . 2 . Tallahassee , Fla. : Florid a Geological Survey . Tibbals , C.H . 1981 . Computer simulation o

f th e steady-state flo w system of the Tertiary limestone (Floridan) aquifer system in eastcentral Florida. Wate r

Resource s Investigation s Ope n Fil e Repor t 81-681 . Tallahassee , Fla. : U.S . Geologica l Survey .

. 1990 . Hydrology o

f th e Floridan aquifer

system i n eastcentral Florida. Professiona l Pape r 1403-E . Washington , D.C. : U.S . Geological Survey . Toth , D.J . 1990 . Geohydrologic summary o f th e Floridan aquifer

i n coastal areas of Nassau, Duval, and

northeast St. Johns counties. Technical Repor t

SJ90-5 . Palatka , Fla. : St . John s River Wate r Managemen t

District . Vernon , R.O . 1951 . Geology o f Citrus an d

Levy counties, Florida. Geological Bulleti n No . 33 . Tallahassee , Fla. : Florid a Geological Survey . Wyrick , G.G . 1960 . Th e ground-water resources o

f Volusia County, Florida. Repor

t o f Investigation s No . 22 . Tallahassee , Fla. : U.S . Geologica l Survey .

St. Johns River

Water Management

District 52