GROUND-WATER HYDROLOGY OF 

VOLUSIA COUNTY, FLORIDA, WITH 

EMPHASIS ON OCCURANCE AND 

MOVEMENT OF BRACKISH WATER 

By A. T. Rutledge 

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 84-4206

In cooperation with 

VOLUSIA COUNTY, FLORIDA 

1985
U.S. DEPARTMENT OF THE INTERIOR 

DONALD PAUL HODEL, Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

The use of firm, trade, and brand names in this report is for identification purposes only and 

does not constitute endorsement by the U.S. Geological Survey. 

For additional information

write to:

District Chief

U.S. Geological Survey

Suite 3015

227 N. Bronough Street

Tallahassee, FL 32301

Copies of this report can be

purchased from:

U.S. Geological Survey

Branch of Information Services

Box 25286

Denver, CO 80225-0286

800-ASK-USGS

Additional information about water resources in Florida is available on the 

World Wide Web at http://fl.water.usgs.gov 
CONTENTS 

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

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

Background and problems............................................................................................................................. 3

Purposes and scope ....................................................................................................................................... 4

Previous work................................................................................................................................................ 5

Data collection .............................................................................................................................................. 5

Well-numbering system................................................................................................................................. 5

Environmental setting ...................................................................................................................................... 6

Climate ........................................................................................................................................................ 6

Geography................................................................................................................................................... 6

Geology....................................................................................................................................................... 9

Hydrogeology.............................................................................................................................................. 9

Ground-water use ............................................................................................................................................. 14

Surficial aquifer........................................................................................................................................... 16

Floridan aquifer system............................................................................................................................... 16

Water-level trends............................................................................................................................................. 19

Surficial aquifer........................................................................................................................................... 19

Floridan aquifer system............................................................................................................................... 27

Water budget .................................................................................................................................................... 34

Surficial layer ................................................................................................................................................... 34

Rainfall and evapotranspiration ............................................................................................................. 34

Streamflow ............................................................................................................................................. 34

Vertical leakage ...................................................................................................................................... 36

Water budget of the surficial layer ......................................................................................................... 38

Floridan aquifer system............................................................................................................................... 38

Specific capacities.................................................................................................................................. 40

Testing estimates of flow in the Floridan aquifer system against recharge estimates............................ 42

Water budget of the Floridan aquifer system ......................................................................................... 45

Concepts of brackish water occurrence and movement................................................................................... 46

Baseline salinity .......................................................................................................................................... 46

Chloride concentration change ratio ........................................................................................................... 46

Physical nature of freshwater-saltwater interface ....................................................................................... 49

Brackish water in the surficial aquifer ............................................................................................................. 51

Present distribution...................................................................................................................................... 51

Comparision of past and present ................................................................................................................. 51

Brackish water in the Floridan aquifer system................................................................................................. 51

Present distribution...................................................................................................................................... 51

Comparision of past and present ................................................................................................................. 56

Nonpublic-supply wells ......................................................................................................................... 56

Public-supply wells ................................................................................................................................ 60

Effects of management alternatives on movement of brackish water.............................................................. 67

Surficial aquifer........................................................................................................................................... 67

Floridan aquifer system............................................................................................................................... 67

Contents iii 
Summary.......................................................................................................................................................... 74

Selected references .......................................................................................................................................... 76

Supplemental data--chloride concentrations in public-supply wells............................................................... 78

ILLUSTRATIONS 

Figure 1. Map showing location of Volusia County and ridge areas and major physiographic features in

Volusia County................................................................................................................................ 3

2. Hydrograph showzing average yearly rainfall during 5-year intervals at three rain gages, 

1951-80 .......................................................................................................................................... 8

3. Map showing topography in Volusia County................................................................................. 10

4. Geologic sections ........................................................................................................................... 11

5. Map showing areas of artesian flow from the Floridan aquifer system in Volusia County, 

September 1982.............................................................................................................................. 13 

6. Map showing altitude of top of Floridan aquifer system ............................................................... 15

7. Map showing distribution of surf icial-aquifer wells that are used for irrigation purposes........... 17

8. Map showing distribution of surficial-aquifer wells that are used for domestic purposes ............ 18

9. Map showing locations of public-supply wells and available water-use rates, 1955 .................... 20

10. Map showing locations of public-supply wells and water-use rates, 1980.................................... 21

11. Map showing distribution of Floridan aquifer system wells that are used for irrigation and which 

are greater than 4 inches in diameter.............................................................................................. 22

12. Map showing distribution of Floridan aquifer system wells that are used for irrigation and which

are 4 inches or less in diameter ...................................................................................................... 23 

13. Map showing distribution of Floridan aquifer system wells that are used for domestic purposes 24 

14. Map showing locations of the major artificial drainage systems in Volusia County ..................... 25

15. Hydrograph showing daily maximum water levels in surf icial-aquifer wells 910-110-13 and 

913-116-01, January 1978-December 1983 ................................................................................... 26

iv Contents 
Figure 16. Hydrograph showing monthly rainfall for the 18-month periods up to and including months of 

three mass water-level measurements on Floridan aquifer system wells............................................ 28 

17. Map showing potentiometric surface of the upper part of the Floridan aquifer sytem, November 

1955................................................................................................................................................ 29 

18. Map showing potentiometric surface of the upper part of the Floridan aquifer system, September 

1982, and area in which the potentiometric surface declined more than 10 feet from November 

1955 to September 1982................................................................................................................. 30 

19. Map showing potentiometric surface of the upper part of the Floridan aquifer system, May 

1981................................................................................................................................................ 31 

20. Hydrographs showing water-level records of five Floridan aquifer system wells, 1955-83 ......... 32 

21. Hydrographs showing daily water levels in four Floridan aquifer system wells, January 1981-

December 1983 .............................................................................................................................. 33 

22. Map showing surface-drainage features, stream-gaging stations, and rain gages ......................... 35 

23. Map showing ratios of specific capacity to length of open hole for Floridan aquifer system 

wells of 6-inch and larger diameters .............................................................................................. 41 

24. Map showing potentiometric surface of the upper part of the Floridan aquifer system, September 

1982, and four drainage areas for which flow analyses are given ................................................. 43

25. Hydrographs showing periodic records of chloride concentration in water from Floridan aquifer

system wells that have not been used for public supply, January 1978-June 1979 ....................... 47 

26. Hydrographs showing periodic records of chloride concentration in water from Floridan aquifer

system wells that have not been used for public supply, 1953-83 ................................................. 48 

27. Conceptual cross sections showing the occurrence of brackish ground water and the movement 

of brackish water caused by pumping............................................................................................ 50

28. Map showing the chloride concentration in the surficial aquifer and chloride concentration 

change ratios for water from wells that tap the surficial aquifer ................................................... 52

29. Diagram showing average ionic composition of water from eight surficial-aquifer wells in 

central Volusia County ................................................................................................................... 53

30. Map showing chloride concentration in water from wells that tap the upper part of the 

Floridan aquifer system ................................................................................................................. 54

31. Map showing estimated maximum thickness of zone in the Floridan aquifer system in which 

the water is fresh or slightly brackish ............................................................................................ 55

Contents IV 
Figure 32. Diagram showing average ionic compositions of water in three parts of the Floridan aquifer 

system............................................................................................................................................. 57

33. Map showing locations of 21 Floridan aquifer system wells for which analyses of ion 

concentrations in water are given................................................................................................... 58 

34. Map showing chloride-concentration change ratios for wells open to the Floridan aquifer 

system that have not been used for public supply.......................................................................... 59 

35. Map showing chloride-concentration change ratios based on old data versus data from

March-April 1982 for public-supply wells .................................................................................... 64 

36. Map showing chloride-concentration change ratios based on old data versus data from

August 1982 for public-supply wells ............................................................................................. 65

37. Map showing chloride-concentration change ratios based on old data versus data from

December 1982 for public-supply wells ........................................................................................ 66

38. Hydrographs showing chloride concentration of water from three Daytona Beach publicsupply wells, 1974-83 .................................................................................................................... 68 

39. Hydrographs showing chloride concentration of water from four Holly Hill public-supply wells, 

1979-83 .......................................................................................................................................... 69 

40. Map showing public-supply wells in use during 1954-57 and chloride concentrations of water 

from public-supply wells in northeast Volusia County .................................................................. 70 

41. Map showing public-supply wells in use during 1982 and chloride concentrations of water from 

public-supply wells in northeast Volusia County........................................................................... 71

42. Conceptual cross section shoving movement of freshwater-saltwater interface under pumping 

wells ............................................................................................................................................... 73 

TABLES 

Table 1. Data on wells referenced in this report which have been inventoried ............................................... 7 

2. Estimated ground-water use in Volusia County ............................................................................. 14

3. Measured and estimated average streamflow for six gaging stations ............................................ 37 

4. Estimated water budget of the surficial layer for each topography-hydrology type...................... 39 

5. Estimated water budget of the Floridan aquifer system in Volusia County................................... 45 

6. Chloride concentrations in water from wells in the monitoring network suggested in the 

northwest Volusia County report.................................................................................................... 61

vi Contents 
CONVERSION FACTORS 

For use of those readers who may prefer to use metric units rather than U.S. inch-pound units, 

the conversion factors for the terms used in this report are listed below: 

Multiply By Length To obtain 

inch (in.) 25.4 millimeter (mm) 

foot (ft) 0.3048 meter (m) 

mile (mi) 1.609 kilometer (km) 

Area 

square foot (ft

2) 0.0929 square meter (m2) 

square mile (mi2) 2.590 square kilometer (km2) 

Flow 

gallon per minute (gal/mm) 0.003785 cubic meter per minute 

(m3/min) 

million gallons per day 

(Mgal/d) 

0.0438 cubic meter per second (m3/s) 

inch per year(in/yr) 25.4 millimeter per year (m3/s) 

cubic-foot per second (ft

3/s) 0.02832 cubic meter per second (m3/s) 

Transmissivity 

foot squared per day (ft

2/d) 0.0929 meter squared per day (m2/d) 

Contents IV
GROUND-WATER HYDROLOGY OF VOLUSIA COUNTY, FLORIDA, WITH EMPHASIS 

ON OCCURRENCE AND MOVEMENT OF BRACKISH WATER 

By A. T. Rutledge
 

ABSTRACT
 

Volusia County is a 1,200—square—mile area in east—central Florida which
 

includes the communities of Daytona Beach, Ormond Beach, New Smyrna Beach,
 

Deland, and Deltona. The area is oriented toward tourism, especially along the
 

coast.
 

The two aquifers underlying the area are the unconfined surficial aquifer
 

and the confined Floridan aquifer system. The surficial aquifer consists of
 

sand, clay, and shell beds of Pleistocene and Holocene age, and the Floridan
 

aquifer system consists of limestone and dolomite of Eocene age. The two aqui­


fers are separated by confining clay beds of Miocene or Pliocene age. Both
 

aquifers contain good quality water in most of Volusia County, but brackish
 

water is present in the eastern and western fringes of the county in the surfi­


cial aquifer and in the upper zones of the Floridan aquifer system presently
 

tapped by wells. Saltwater is present throughout the county in the relatively
 

untapped lower zones of the Floridan aquifer system. Development in the fringes
 

has caused movement of the brackish water. There is a need for an understanding
 

of this movement so that future problems can be avoided.
 

Average ground-water withdrawal in 1980 in Volusia County was6 6 million
 

gallons per day, of which 30 was for public supply, 24 was for agricultural
 

irrigation, and 12 was for other uses. Ground—water use quadrupled between 1955
 

and 1980. More than 95 percent of the ground water pumped is from the Floridan
 

aquifer system.
 

Water levels in Floridan aquifer system wells declined more than 10 feet
 

over an area of 70 square miles from 1955 to 1982. This drawdown, which occurred
 

in the area of Ormond Beach, Daytona Beach, and Port Orange, was caused by pump­


ing.
 

The annual water budget of the surficial layer consists of 53 inches rain-


fall, 1 inch upward leakage from the Floridan aquifer system, 0.5 inch recharge
 

from Floridan aquifer system withdrawals, and 0.5 inch stream inflow, counter-


balanced with 39 inches evapotranspiration, 11 inches stream outflow, and 5
 

inches downward leakage to the Floridan aquifer system.
 

1
 
The annual water budget of the Floridan aquifer system consists of 5 inches
 

downward leakage inflow, 1 inch upward leakage outflow, 1 inch horizontal
 

inflow, 1.5 inches horizontal outflow, 2.5 inches discharge from springs and
 

flowing wells, and 1 inch pumpage.
 

Brackish water movement, or intrusion, apparently is occurring in the surf­


icial aquifer on the barrier island in the northeast part of the study area.
 

Intrusion is probably occurring in other sections of the barrier island, but
 

there is no evidence that it is occurring in inland areas. Future intrusion is
 

likely in the surficial aquifer on the barrier island as groundwater withdraw­


als increase.
 

There is little evidence that intrusion is occurring uniformly over large
 

areas in the Floridan aquifer system. Most nonpublic supply wells have not
 

exhibited long—term changes in salinity, although significant increases in
 

chloride concentration in water from five nonpublic supply wells in the coastal
 

area of Ormond Beach and Daytona Beach may be associated with ground—water
 

withdrawals in northeast Volusia County. Vertical intrusion is occurring at
 

sites of public supply pumping because these wells are usually deeper, are
 

pumped a greater amount of the time, and are pumped at higher rates. Many of
 

these wells in the eastern and western fringes of Volusia County have been
 

abandoned and replaced by new wells closer to the central part of the county.
 

Water—management practices that may minimize future movement of brackish
 

water in the Floridan aquifer system include minimizing well depths, minimizing
 

drawdown, installing wells where the freshwater zone is thickest, increasing
 

head in the freshwater zone by using injection wells, and reducing head in the
 

saltwater zone. Drawdown can be reduced by increasing the number of supply
 

wells per desired water—use rate. Minimizing well depth may be the single most
 

effective step against intrusion.
 

INTRODUCTION
 

Background and Problems
 

Volusia county, in east—central Florida, is oriented toward tourism, espe­


cially along the coast. The 1,200—square—mile county is 15 miles north or
 

Orlando and includes the coastal communities of Daytona Beach, Ormond Beach,
 

and New Smyrna Beach in addition to the inland communities of De Land and Del­


tona (fig. 1). Rapid population growth has greatly increased demand on public—
 

water supplies. The two aquifers that supply most of the water are the Floridan
 

aquifer system, a limestone aquifer under artesian conditions in Volusia
 

County, and the surficial aquifer, an unconfined sand aquifer. Although both
 

contain good quality water in most of Volusia County, brackish water is present
 

in the eastern and western fringes of the county in the surficial aquifer and in
 

upper zones of the Floridan aquifer system presently tapped by wells. Saltwater
 

is present throughout the county in lower zones of the Floridan aquifer system
 

not presently tapped. Many of the fringe areas, especially to the east, are populated
 

and are characterized by heavy pumping of ground water and the accompanying drawdown
 

of water levels.
 

2
 

The extent of brackish water has apparently increased in recent years in both
 

aquifers. There is a need to determine the extent, mechanism, and rate of movement
 

of brackish water in the aquifers of Volusia County. Furthermore, there is a need
 

to understand how further movement can be minimized.
 

Purposes and Scope
 

The study of brackish—water occurrence in Volusia County is one of many
 

water—resources investigations that have been conducted by the U.S. Geological
 

Survey in cooperation with Volusia County. The purposes of this study, which was
 

conducted during 1980—82, were to:
 

1.	 Evaluate ground—water use, water—level trends, and the water budget for both
 

aquifers;
 

2.	 Determine the occurrence of brackish water in the upper part of the Floridan
 

aquifer system and in the surficial aquifer;
 

3.	 Differentiate between areas of naturally occurring brackish ground water and
 

areas of recent intrusion;
 

4.	 Differentiate between areas of lateral and vertical brackish water intrusion
 

and investigate the cause and extent of the intrusion; and
 

5.	 Describe the effects of alternative water—management actions that could min­


imize future saltwater intrusion.
 

This report is the full documentation of all results of the study. The infor­


mation here includes the following: an assessment of ground—water withdrawals
 

from both aquifers, a detailed description of water—level trends for the Floridan
 

aquifer system, estimates of the water budgets of the surficial layer and the
 

Floridan aquifer system, maps showing chloride concentration in both aquifers
 

throughout the study area, an assessment of evidence of saltwater intrusion in
 

surficial—aquifer wells and in nonpublic supply wells open to the Floridan aqui­


fer system, a separate assessment of evidence of intrusion in public—supply wells
 

open to the Floridan aquifer system, and descriptions of possible countermeasures
 

against future intrusion.
 

The study encompassed the entire county, although emphasis was on data col­


lection in the eastern and western fringes where brackish water is present in the
 

upper Floridan aquifer system and in the surficial aquifer. Most data collection
 

for this study was done during 1981—82, although numerous analyses in this report
 

involve pre—1981 data. For the purpose of determining changes in water levels and
 

water quality due to development, recent data were compared to data collected
 

mainly during 1953—56.
 

Detailed analysis is limited generally to the surficial aquifer and the upper
 

Floridan aquifer system. Detailed analyses of the lower zones of the
 

4
 
Floridan are not possible because of the scarcity of data. For the purposes of
 

areal calculations, the study area does not include the areas of Lake George, Lake
 

Monroe, and Lake Harney.
 

Previous Work
 

The general ground—water hydrology of Volusia County was described by Wyrick
 

(1960, 1961). His investigation is most valuable to this report because it pro­


vides the historical water—level and water—quality data base which is needed to
 

determine long—term changes caused by development. Knochenmus and Beard (1971)
 

assessed the quality and quantity of the surface—water and ground-water resources
 

of Volusia County; the section on ground water in that report provides additional
 

water—quality data for many wells that had been previously sampled by Wyrick. A
 

map report by Knochenmus (1968) discussed drainage feasibility throughout the
 

county. Bush (1978) presented a ground—water flow model of Volusia County. Simo­


nds and others (1980) demonstrated relations between water—level trends in the
 

surficial aquifer and vegetative classifications in central Volusia County. Rut-


ledge (1982) evaluated the effects of irrigation withdrawals on the Floridan
 

aquifer system in northwest Volusia County.
 

Water—resources data collected in the county include several daily or peri­


odic records of stream discharge, stream stage, and water levels in wells. Many of
 

these records span more than 20 years. Long—term records of water—quality and
 

discharge have been maintained for two springs in Volusia County and long—term
 

records of stage have been maintained for two lakes. All of these records exceed
 

15 years in length.
 

Data Collection
 

Data collection for this study included water—level measurements in wells,
 

water sampling from wells, and operation of water—level recorders to monitor
 

variation of water level with time. Specific—capacity tests were made to provide
 

a better understanding of the hydrologic properties of the Floridan aquifer sys­


tem.
 

Much of the data collection effort involved the inventory update of many
 

wells that were inventoried by Wyrick (1960, 1961). Additional wells were inven­


toried where needed. All major public—supply (municipal) wells were inventoried.
 

Well—Numbering System
 

Wells inventoried by the U.S. Geological Survey are referenced by local well
 

numbers based on latitude and longitude coordinates derived from a grid of 1—
 

minute parallels of latitude and longitude. Numbers consist of the last digit of
 

the degree and the two digits of the minute of the line of latitude on the south
 

side of the quadrangle, the last digit of the degree and the two
 

5
 
digits of the minute of the line of longitude on the east side of the quadrangle,
 

and the two—digit sequence number assigned in the order in which the well within
 

the quadrangle was inventoried. For example, well 905—116—02 was the second well
 

inventoried in the 1—minute quadrangle north of lat 29°05’ and west of long
 

81°16’.
 

Table 1 gives information about the wells referenced by local well number in
 

this report. Additional data for a well may be retrieved from the computer files
 

of the U.S. Geological Survey. This data is retrieved by the 15—digit station num­


bers shown in the table. As of the date of this publication, more than 1,000 wells
 

have been inventoried by the U.S. Geological Survey in Volusia County.
 

ENVIRONMENTAL SETTING
 

Climate
 

The climate in Volusia County is subtropical; the average temperature is 71°F
 

and the average rainfall is 53 inches per year. The coldest months are December,
 

January, and February, when temperatures average around 60°F; the warmest are
 

June, July, and August which average around 80°F. More than half of the yearly
 

rainfall occurs during the humid summer months of June—September.
 

Long—term yearly rainfall records are shown in figure 2. Rainfall has been
 

slightly higher than average at the De Land site in recent years, and slightly
 

below average at the Crescent City site. Long—term rainfall is noticeably lower
 

near the coast than it is inland.
 

Geography
 

From a broad perspective, the topography in Volusia County is of two types:
 

Karst topography and leveled terraces. Karst topography is the name applied to
 

the undulating, pitted land surface that occurs where sinkholes are numerous and
 

drainage is primarily downward. This type of topography is common in the areas in
 

Volusia County where land surface is highest——the Crescent City Ridge and the De
 

Land Ridge (fig. 1). The remaining areas are characterized as leveled terraces.
 

Surface drainage is more typical of these leveled terraces.
 

Terrace formation during the Pleistocene played an important part in shaping
 

the land surface in Volusia County (Cooke, 1945; Wyrick, 1960). Terraces are
 

expanses of land of relatively uniform altitude which were the sea floor when the
 

sea level stood higher than present sea level. Terrace formation accounts for the
 

flatness of much of Volusia County. The Crescent City Ridge and the De Land Ridge
 

are remnants of the Penholoway Terrace, which has been eroded largely by sinkhole
 

activity. The other three terraces in Volusia County (fig. 1) are relatively
 

unchanged and are therefore relatively level.
 

6
 
Table 1.-- Data on well referenced in this report which have been inventoried 

STATION AQUIFER ALT DEPTH 

NO. LOCAL NO. AND WELL NAME PENETRATED LAND WELL 

284736080515101 84705106 COUNTY LINE WELL NR MAYTOWN,FL FLRD 6 200 

284821081075501 84810701 LEMON BLF FSM CMP WELL,S.OF OSTEEN, FL FLRD 10 138 

284857081081201 84810801 LEMON BLUFF WATER ASSOC., S. OF OSTEEN FLRD -- 202 

285105080515801 85105101 PUTNAM GROVES WELL, SW OF OAK HILL FLRD 6 90 

285341080532401 85305302 BROWN & COPELAND WELL, NR ARIEL FLRD 8 225 

285403080514390 35405103 INDIAN MARS. ESTATES OF EDGEWATER FLRD 10 150 

285512081202801 85512001 USGS WELL 1.9MI S.OF BLUE SPG NROR.CTY FLRD 9.52 200 

285636081175501 85611702 ORAN.CITV P.S. WELL #3, ORANGE CITY FLRD 23 257 

285745081054001 85710501 USGS OBSER WELL AT ALAMANA, FL. FLRD 35.9 121 

285716081053901 85710502 USGS TEST WELL 12, N.OF LK.ASHBY FLRD 35 241 

285953083574701 85905709 NSB PS WELL. NUMB 4 IN 1980, N.SMYRNA FLRD 22.12 190 

290107081062001 90110602 USGS TEST WELL. E 1, W.SAMSULA FLRD 41 111 

290129081072901 90110701 USGS TEST WELL 8, W.SAMSULA FLRD 40 241 

290138081203202 90112002 USGS J—2 TEST WELL, W.OF DELAND FLRD 42 500 

290251081001401 90210001 USGS TEST WELL I,NE OF SAMSULA FLRD 26 700 

290324080580501 90305801 MENDRICKS WELL TURNBULL BAY ROAD, NSB FLRD 7 104 

290447081102301 90411004 I-4 DEEP WELL, E OF DELAND FLRD 39.9 241 

290541081132902 90511304 USGS 04 DP TEST W.NR DELAND, FL.6"CSG FLRD 38.35 639 

290606083581901 90605803 S. SIDE OF ROSE BAY, ALLANDALE FLRD 5 125 

290651080582802 90605814 HARBOUR OAKS SUP.WELL,ALLANDALE FLRD 3.72 150 

290646081213701 90612101 16S29E W.WARDS WELL,W DELEON SPRINGS FLRD 57 325 

290612081214101 90612107 MAGSTROM DSL WELL, N. GLENWOOD FLRD 46 --

290704081155301 90711502 16S30E11 HAGSTROMS 10"MARSH RD WELL FLRD 54 600 

290804081215601 90712101 12” FLOW N OF DELEON SPRINGS FLRD 5 210 

290752081220901 90712102 8”FLOW WELL W.OF DELEON SPRINGS FLRD 5 96 

290816080574101 90805701 DON MEMBRY WELL IN WILBUR-BY-THE-SEA FLRD 12 130 

290920081063001 90910601 USGS OBSER NR DAYTONA BEACH, FL. FLRD 27.04 235 

290959031231601 90912301 DAIRY FLOW WELL #1,SW OF BARBERVILLE FLRD 12 241 

291025081050201 91010501 USGS OBSER NR I—95 AT DAYTONA BCH., FL FLRD 26.05 498 

291032081065201 91010601 DAYTONA P.S. WELL #49, SW OF DAYTONA FLRD 28 210 

291004081101401 91011001 TIGER BAY TEST WELL 1A, W OF DAYTONA FLRD 41 220 

291007081101613 91011013 TIGER BAY TEST WELL 350 SM NR DAYTONA SURF 41.17 20 

291036081175801 91011701 HENDRIX WELL CN SR11, E OF BARBERVILLE FLRD 43.93 180 

291107080591601 91105902 BLUE WATERS MCTEL. WELL, DAYTONA BCH FLRD 25 133 

291133081035801 91110302 DAYTONA P.S. WELL #37, DAYTONA FLRD 28 205 

291133081040601 91110404 G.E. PLANT 6-INCH W. AT DAYTON BEACH,F FLRD 27.55 235 

291124081043401 91110410 DAYTONA P.S. WELL #41, DAYTONA FLRD 28 290 

291105031052301 91110504 DAYTONA P.S. WELL #46, DAYTONA FLRD 33 210 

291155081022901 91210237 DAYTONA P.S. WELL #32, TUSC., DAYTONA FLRD -- 160 

291353081160401 91311601 UNION CAMP SHALLOW WELL NR BARBERVILLE SURF 34.13 20 

291429081024702 91410213 HOLLY HILL P.S. WELL #7A, HOLLY HILL FLRD 9.2 200 

291425081024501 91410214 HOLLY HILL P.S. WELL #8, HOLLY HILL FLRD 9 215 

291436081024701 91410216 HOLLY HILL P.S. WELL #9, HOLLY HILL. FLRD 8.02 216 

291435081025501 91410218 HOLLY HILL P.S. WELL. #ll, HOLLY HILL FLRD 8 --

291646081034501 91610306 ORMOND P.S. WELL #6, ORMOND BEACH FLRD 8 200 

291715081281801 91712801 J.C. MEW WELL AT SEVILLE, FL. FLRD 14.9 180 

291835081324201 91813201 USED 426 PINE ISLAND, W.OF SEVILLE FLRD 4.36 155 

291904081055501 91910504 TOMOKA ESTATES 2” WELL NW OF ORMOND FLRD 8.59 140 

7 

Land surface altitude ranges from 0 to 120 feet in Volusia County. The topographic
 

highs are in the Crescent City Ridge and the De Land Ridge. Lowest areas are along
 

the coast and in the St. Johns River valley (fig. 3). Generally, land surface
 

altitude rises in a steplike progression from the Silver Bluff Terrace to the Pam­


lico Terrace to the Talbot Terrace to the ridges in western Volusia County.
 

Geology
 

Four stratigraphic units are discussed in the following paragraphs and are
 

illustrated in figure 4. Descriptions of the formations are from Wyrick (1960)
 

and figure 4 was derived from geologic logs of the Florida Bureau of Geology (for­


merly Florida Geological Survey). Well numbers on these figures are assigned by
 

the Florida Bureau of Geology. The Oldsmar Limestone of early Eocene age,
 

although illustrated, is not discussed because no known water wells penetrate it
 

in the study area.
 

The sediments of Pleistocene and Holocene age consist of fine— to medium—
 

grained quartz sand, sandy clays, and locally, small amounts of shell. In some
 

areas, the sand has been cemented into “hardpan” by deposition of iron oxide at
 

the water table. The Pleistocene and Holocene deposits are generally 20 to 50 feet
 

thick, but locally they can be as much as 100 feet thick.
 

The Miocene and Pliocene deposits consist of unconsolidated beds of fine
 

sand, shells, and calcareous silty clays. The overall thickness of the Miocene or
 

Pliocene deposits in Volusia County is generally 20 to 70 feet.
 

The Ocala Limestone, of late Eocene age, is composed of cream to white lime-


stone mottled with gray zones. The Ocala Limestone is generally only slightly
 

dolomitized in Volusia County. Because of extensive erosion the formation is thin
 

in most of Volusia County, and absent in much of the De Land Ridge.
 

The Avon Park Limestone of late middle Eocene age, varies in color from
 

chalky white to light brown or ashen gray, and consists of layers of dark—brown
 

dolomite separated by layers of chalky limestone. The dolomite is crystalline and
 

contains few fossils, but the limestone is very fossiliferous. The limestone is
 

extensively dolomitized. Some of the Avon Park Formation was removed by erosion
 

before the overlying Ocala Limestone was deposited.
 

Hydrogeology
 

The aquifers discussed are the surficial aquifer and the Floridan aquifer
 

system. The surficial aquifer is composed of poorly consolidated sand, clay, and
 

shell beds of Pleistocene and Holocene ages. The Floridan aquifer system is made
 

up of the limestone and dolomite of Eocene age. Although the shell beds of Miocene
 

and Pliocene ages may yield some water, these beds are excluded from discussion
 

because few wells in Volusia County are open to them. Of
 

9
 


greater importance from a hydraulic standpoint are the clay layers of Miocene or
 

Pliocene age which form the confining bed that retards water movement between the
 

surficial aquifer and the Floridan aquifer system.
 

The surficial aquifer is the layer of sand and shell from land surface down
 

to the first areally persistent and relatively impermeable layer of clay, or down
 

to the limestone if no clay bed thus described is present. Although the surficial
 

aquifer may contain local zones of clay and hardpan, the clay zones are inconsis­


tent enough and the hardpan is permeable enough that these do not significantly
 

retard the flow of water in the aquifer. The surficial aquifer is generally 10 to
 

50 feet thick. It is thickest in the De Land Ridge area, where it reaches 100 feet
 

in some places.
 

The surficial aquifer is unconfined because it contains the top of the zone
 

of saturation, the water table, which is free to rise and fall in the aquifer.
 

Typical seasonal water—table fluctuations range from 4 to 5 feet. The average
 

depth to the water table in most of Volusia County is less than 10 feet, although
 

in the De Land Ridge area depths typically exceed 20 feet. In other ridge areas
 

(fig. 1), the average depth to the water table is typically 5 to 15 feet, but in
 

nonridge areas the average depth to the water table is only 0 to 5 feet. Simonds
 

and others (1980) showed relations between depth to the water table and vegeta­


tive classification.
 

Water enters the surficial aquifer by direct infiltration of rainfall,
 

recharge caused by application to the land surface of Floridan aquifer system
 

withdrawals, streamfiow, and leakage in areas of upward gradient from the Flori­


dan aquifer system. It leaves as evapotranspiration, streamflow, and leakage in
 

areas of downward gradient to the Floridan aquifer system. Lateral movement into
 

or out of the study area in the surficial aquifer is small because hydraulic gra­


dients are small and the ability of the aquifer to transmit water is slight.
 

Water levels in wells open to the Floridan aquifer system in Volusia County
 

are above the top of the aquifer. In areas of artesian flow (fig. 5) the water
 

level in wells is above land surface. In other parts of Volusia County, the water
 

level in Floridan aquifer system wells is generally 10 to 40 feet below land sur­


face. Because the Floridan aquifer system is artesian, it is completely saturated
 

from bottom to top. Although water levels cannot rise and fall within the aquifer,
 

they can rise and fall in wells that penetrate the aquifer. This fluctuation is
 

indicative of pressure changes within the aquifer. Typical seasonal water—level
 

fluctuations are 4 feet in undeveloped areas and 5 to 10 feet in areas of pumping.
 

The surface defined by water levels in wells tapping the Floridan aquifer system
 

is called the potentiometric surface of the Floridan aquifer system. The slope of
 

this surface denotes the direction of lateral ground—water flow within the aqui­


fer. Furthermore, the difference in altitude between the water table and the
 

potentiometric surface determines the direction of leakage between the aquifers.
 

If the water table is higher than the potentiometric surface, then the leakage is
 

from the surfical aquifer down to the Floridan aquifer system. Conversely, if the
 

potentiometric surface is higher than the water table, then the leakage is from
 

the Floridan aquifer system up to the surficial aquifer.
 

12
 

 Water enters the Floridan aquifer system in Volusia County by downward leakage
 

from the surficial aquifer through the confining layer and by horizontal inflow
 

from outside Volusia County. It leaves as upward leakage through the confining
 

layer, spring discharge, well discharge, and horizontal outflow to other areas.
 

Figure 6 shows the altitude of the top of the Floridan aquifer system. The
 

top of the freshwater zone is located at this surface and the thickness of this
 

zone is zero to 1,400 feet depending on location. The freshwater zone is thinnest
 

in coastal areas and near the St. Johns River and thickest in central Volusia
 

County. Below this freshwater zone are limestone and dolomite formations that are
 

saturated with saltwater.
 

GROUND-WATER USE
 

Estimates of ground—water use are given in table 2. Withdrawal rates have
 

approximately tripled during 1955—80 for all uses except irrigation. Irrigation
 

use has increased more than tenfold, probably because of the increased use of
 

water for irrigating the leather leaf fern, which is grown commercially on the
 

Crescent City Ridge and the De Land Ridge. The largest withdrawals are for public—
 

supply use; irrigation water use ranks second. In 1980, all other water uses com­


bined made up less than the public supply or the irrigation use. Total ground—
 

water use has quadrupled between 1955 and 1980.
 

Table 2.--Estimated ground—water use in Volusia County
 

[In million gallons per day]
 

1955 1967 1980 

Public Supply 10 15.8 30.2 

Agricultural irrigation 1.7 6.1 23.7 

Domestic, self-supplied 1.8 2.0 4.5 

Heat pump and lawn irrigation 2.0 3.4 6.2 

Other 0.5 0.6 1.2 

Totals 16.0 27.9 65.8 

1/Source
 

1955 - Knochenmus and Beard, 1971, and Florida Bureau of 
 

Geology project files
 

1967 - Files of U.S. Geological Survey
 

1980 - Project files of U.S. Geological Survey and St. Johns 
 

River Water Management District
 

14 
 

More than 95 percent of the ground water withdrawn in Volusia County is
 

pumped from the Floridan aquifer system, and the remainder is taken from
 

the surficial aquifer. The following discussion deals with the various
 

categories of water use for both aquifers and shows how withdrawals for
 

each category are distributed in the study area.
 

The VOLDATA file, which is mentioned in this section, is a data file
 

maintained by the Volusia County Building Inspection Department and
 

includes data on all wells permitted by that department since 1976. It is
 

useful as a source of information pertaining to water use. Additional data
 

continue to be added to VOLDATA.
 

Surficial Aquifer
 

In Volusia County, the total present (1980) pumpage from the surfi­


cial aquifer is approximately 3 Mgal/d. There are very few agricultural
 

irrigation wells and no public—supply wells that are open to the surficial
 

aquifer. Most of the agricultural irrigation wells tapping the surficial
 

aquifer are located in the Crescent City Ridge area and are used for irri­


gating ferneries. The total pumpage from these wells is probably much less
 

than 1 Mgal/d.
 

Water from the surficial aquifer is used mostly for lawn irrigation. 

Figure 7 shows the distribution of surficial aquifer irrigation wells in 

the VOLDATA file. In January 1983, there were 1,952 surficial aquifer 

irrigation wells in the VOLDATA file out of a total of 7,257 for all well 

types, or 27 percent. An estimate of the pumpage in Volusia County from 

the surficial aquifer for lawn irrigation purposes is about 2 Mgal/d. This 

is based on these assumptions: (1) there are approximately 5,000 lawns 

irrigated with water from the surficial aquifer, (2) the average lawn is 

8,000 ft, (3) the average application rate is 30 in/yr. As figure 7 shows, 

most surficial aquifer irrigation wells are in coastal areas. Although the 

surficial aquifer is an important source for lawn irrigation, its contribution to total agricultural irrigation is small. 

The second largest use of water from the surficial aquifer is for
 

domestic purposes. The VOLDATA file contained data for 390 surficial aqui­


fer domestic wells of a total of 2,600 domestic wells on January 1983. An
 

estimate of the domestic pumpage from the surficial aquifer may be obtined
 

by multiplying the ratio 390/2600 by the total domestic ground—water use
 

in table 2; the pumpage from the surficial aquifer for domestic use is
 

thus 0.7 Mgal/d. Figure 8 shows that most of these wells are located in
 

the New Smyrna Beach and Edgewater areas.
 

Floridan Aquifer System
 

All but a small fraction of the ground water used in Volusia County is
 

from the Floridan aquifer system. All public—supply wells and most agri­


cultural irrigation wells are open to the Floridan aquifer system.
 

16 


Figures 9 and 10 show the distributions of public—supply wells in 1955 and
 

1980. Also shown are the pumping rates for each supplier. Daytona Beach is the
 

largest supplier. Public suppliers shown in figure 10 that are not shown in
 

figure 9 were not in existence in 1955.
 

Figure 11 shows that the greatest concentration of agricultural irrigation
 

wells is in northwest Volusia County, where most of the fern industry is
 

located. The map shows the distribution, as documented in the VOLDATA file, of
 

Floridan aquifer system wells used for irrigation which are greater than 4
 

inches in diameter. The 1980 withdrawal rate for agricultural irrigation was
 

23.7 Mgal/d.
 

Figure 12 is a plot of Floridan aquifer system wells documented in the
 

VOLDATA system that are used for irrigation and which are 4 inches or less in
 

diameter. A few of the wells in this group may be used for agricultural irriga­


tion, but most are used for lawn irrigation. The greatest concentrations are in
 

the areas of Ormond Beach, Daytona Beach, and Port Orange.
 

Figure 13 is a map showing the distribution of Floridan aquifer wells doc­


umented in the VOLDATA file that are used for domestic purposes. The greatest
 

numbers of these wells are in the De Land Ridge.
 

WATER-LEVEL TRENDS
 

In Volusia County, the practices that cause lowering of water levels are
 

pumping or drainage or a combination of the two. Drainage most directly causes
 

water—level declines in the surficial aquifer, but may also induce declines in
 

the Floridan aquifer system because the surficial aquifer acts as a reservoir
 

for recharge to the Floridan aquifer system. The lowering of water levels
 

caused by development may be estimated by comparing recent water levels with
 

water levels measured during a time of less development. Water—level declines
 

due to development are difficult to ascertain because they often are masked by
 

water—level fluctuations caused by variations in rainfall.
 

Surficial Aquifer
 

Water levels in the surficial aquifer have not been monitored extensively
 

in Volusia County. Nonetheless, it is possible to define areas of greatest
 

water—level decline in the surficial aquifer based on amounts of drainage and
 

pumpage. Figures 7 and 8 show that most of the wells open to the surficial
 

aquifer are located in coastal areas where about 3 Mgal/d are pumped for lawn
 

irrigation. The other developmental stress on the surficial aquifer is artifi­


cial drainage. Figure 14 shows that the areas of greatest artificial drainage
 

are the Daytona Beach area, the Port Orange area, and the Lake Ashby area. The
 

largest declines in the surf icial aquifer due to development are, therefore,
 

in the coastal areas and in the Lake Ashby area.
 

Figure 15 shows two water—level records for surficial—aquifer wells unaf­


fected by development, beginning in 1978. The hydrographs show typical
 

19 







fluctuations due to rainfall variations. The troughs in the records during the
 

summer of 1981 were caused by a drought that caused record low water levels at
 

many sites in Volusia County.
 

Floridan Aquifer System
 

Water levels in the Floridan aquifer system measured during the mid—l950’s
 

can be compared to levels measured recently to determine water—level declines
 

due to pumping and drainage. To accomplish this, the water levels obtained at
 

three different times——November 1955, May 1981, and September 1982, are com­


pared. Changes in the potentiometric surface are caused by the net effects of
 

rainfall variations and ground—water development. Figure 16 shows that rainfall
 

totals for the 6 months ending November 1955 and September 1982 were 28.5 and
 

32.5 inches, respectively. Any significant differences between the respective
 

potentiometric surface maps are, therefore, caused mainly by development. The
 

rainfall trend up to May 1981, on the other hand, is different from the other
 

two. Although the periods up to November 1955 and September 1982 represent
 

average rainfall, the period up to May 1981 represents unusually deficient
 

rainfall. The differences between the November 1955 and the May 1981 potentio­


metric surface maps are, therefore, caused by both rainfall trends and develop­


ment.
 

Figures 17, 18, and 19 show the potentiometric surface of the upper part
 

of the Floridan aquifer system for November 1955, September 1982, and May 1981.
 

Also shown in figure 18 is the area in which the potentiometric surface decline
 

from November 1955 to September 1982 exceeds 10 feet. This is a 70—square—mile
 

area which includes much of Ormond Beach, Daytona Beach, and Port Orange. All
 

of this decline may be attributed to pumping. Figure 19 shows a potentiometric
 

surface which has been affected by development and drought. Most of the water—
 

level measurements made in Volusia County for the May 1981 potentiometric sur­


face map were the lowest ever measured. In the Ormond Beach, Daytona Beach, and
 

Port Orange area, the potentiometric surface was below sea level in an area
 

exceeding 100 square miles; in November 1955, potentiometric surface levels
 

there ranged from 3 to 20 feet above sea level.
 

Figure 20 shows long—term water—level hydrographs for five Floridan aqui­


fer system wells. Significant downward trends are apparent for well 911—104—04,
 

located within 300 feet of a public—supply well in Daytona Beach, and for well
 

909—106—01, southwest of Daytona Beach. The downward trends are caused predom­


inantly by increased pumping, and the seasonal fluctuations are caused by vari­


ations in rainfall and pumpage. The seasonal fluctuations at the other three
 

wells are caused by variations in rainfall rates. The lowest water levels gen­


erally occurred in the summer of 1981 because of drought conditions.
 

Further detail of seasonal fluctuations is shown in figure 21. Largest
 

fluctuations occur in areas of pumping. Well 859—057—09 is within a public—sup­


ply well field and 912—102—37 is in a populated area of Daytona Beach. Well
 

857—105—01, in south—central Volusia County, is farthest from areas of pumping.
 

27
 






WATER BUDGET
 

Surficial Layer
 

The surficial layer consists of the land surface, the lakes, streams,
 

ditches, the surficial aquifer, and the vegetation. Generally, the surficial
 

layer includes everything between the atmosphere and the confining layer. An
 

assessment of the water budget of this layer aids the determination of the
 

water budget of the Floridan aquifer system.
 

The water budget of the surficial layer may be expressed generally as:
 

R + LI + SI + RW = ET + LO + SO (1)
 

where
 

R = rainfall;
 

LI = leakage inflow through a confining layer;
 

SI = stream inflow;
 

RW = return water from pumping of Floridan aquifer system;
 

ET = evapotranspiration;
 

LO = leakage outflow; and
 

SO = stream outflow.
 

Rainfall and Evapotranspiration
 

The average annual rainfall in Volusia County for the period 1951—80 was
 

approximately 53 inches based on an average of five stations in and near Volu­


sia County. The locations of five rain gages, and their corresponding 30—year
 

average annual rainfall, are shown in figure 22. Rainfall comprises more than
 

95 percent of the inflow (recharge) to the surficial layer in Volusia County.
 

Evapotranspiration is the return of water from the land surface to the
 

atmosphere. The average evapotranspiration for Volusia County is estimated at
 

39 inches per year based on values used by other investigators in central Flor­


ida. Lichtler and others (1968, p. 145) estimated that in Orange County, evapo­


transpiration is 70 percent of rainfall. Knochenmus and Beard (1971, p. 45)
 

estimated an evapotranspiration rate of 35 inches per year in Volusia County
 

based on a rainfall rate of 52 inches per year. Grubb and Rutledge (1979, p.
 

21) calculated an average evapotranspiration of 40 inches per year in the Green
 

Swamp, an area about 40 miles southwest of Volusia County. The evapotranspira­


tion rate is somewhat variable from place to place depending on the rainfall,
 

the depth to the water table, and other factors such as vegetation type.
 

Streamflow 
 

Streamflow is the second largest outflow from the surficial layer. Volusia
 

County can be subdivided into three major surface drainage areas (fig. 22). One
 

drains north to Middle Haw and Little Haw Creeks, one drains
 

34
 

west into the St. Johns River, and the other drains seaward. Waters in
 

the first two areas are separate in Volusia County, but eventually con-


verge north of Volusia County near Palatka.
 

The locations of six continuous stream—gaging stations are shown in
 

figure 22 along with the long—term streamflow rate, in inches per year,
 

for the area upstream from each gage. These long—term streamflow rates
 

are purported to represent the average flow during the 31—year period
 

1952—82. A 31—year record exists for Little Raw Creek near Seville and
 

for Spruce Creek near Samsula. The records from these two sites were
 

used as indices for estimating the long—term average discharges for the
 

other stations. For example, the 7—year average discharge at Middle Raw
 

Creek for 1976—82 was multiplied by the ratio of the 31—year average of
 

Little Raw Creek over the 7—year average of Little Raw Creek for 1976—82
 

to obtain the 31—year average of Middle Raw Creek. The mean of the long—
 

term average discharge estimated using Little Haw Creek as an index, and
 

the long—term discharge estimated using Spruce Creek as an index, is the
 

streamflow rate shown in figure 22. Table 3 shows measured average dis­


charges for the six streams and shows long—term estimates of discharge
 

for each.
 

The streamflow from a basin is influenced by the type of topography
 

and surface hydrologic conditions in the basin. For example, a basin
 

which includes more areas of artesian flow than ridges will have more
 

streamflow than a basin that includes more ridges than areas of artesian
 

flow. The topography—hydrology types and the characteristic streamflow
 

rate for each may be as follows:
 

Estimated
 

Topography—hydrology type streamflow rate (in/yr)
 

Areas of artesian flow 18
 

Nonridge areas without artesian flow 11
 

Ridge areas with surface drainage 6
 

Ridge areas in closed basins 0
 

Streamflow is mostly outflow from the surficial layer in Volusia
 

County because all significant surface—drainage systems in Volusia
 

County have their headwaters within the county. There is, however, a
 

slight eastward Stream inflow from Flagler County into northeast Volusia
 

County and a westward stream inflow from Brevard County into south Volu­


sia County (fig. 22). The total area from which these streamflows orig­


inate is about 60 square miles, whereas the entire 1,200—square—mile
 

area of Volusia County is contributing to stream outflow. If stream dis­


charge per unit area is about the same for the three counties, then
 

stream inflow is only about 5 percent of stream outflow.
 

Vertical Leakage
 

Although values for vertical leakage between the surficial aquifer
 

and the Floridan aquifer system may be small, they are important in the
 

understanding of the water budget of the two aquifers. Leakage is out-


flow from the surficial
 

36
 

layer in most of Volusia County, but also is inflow to the surficial
 

layer in areas of artesian flow from the Floridan aquifer system.
 

The net leakage to the Floridan aquifer system may be estimated as
 

rain—fall, minus evapotranspiration and streamflow. If it is assumed
 

that rainfall and evapotranspiration are 53 and 39 inches per year,
 

respectively, and that the average streamflow for the six basins shown
 

in figure 22 is 12 inches per year, then the estimated leakage to the
 

Floridan aquifer system in these basins is 2 inches per year. Leakage is
 

estimated as a small residual that results after accounting for the
 

other elements of the water budget. Rainfall and streamfiow are measured
 

but have error built in. Evapotranspiration is only estimated and is
 

subject to greater error. Therefore, the errors in these components
 

place a high degree of uncertainty in the leakage estimate.
 

Water Budget of the Surficial Layer
 

Table 4 gives estimates of the water budget of the surficial layer
 

for four topography—hydrology types. Ridge areas in closed basins have
 

rainfall and evapotranspiration rates that are slightly different from
 

the others. Reported rainfall is slightly higher because most ridge
 

areas in closed basins are located near the De Land rain gage which has
 

an average rainfall of 54 inches per year. Evapotranspiration is lower
 

because the depth to the water table is as much as 50 feet. Upward leak-


age from the Floridan aquifer is zero with the exception of one topogra­


phy—hydrology type. Streainflow rates vary as estimated previously.
 

Streamflow and downward leakage supplement each other in that an area of
 

high streamflow will have low downward leakage, and an area of low
 

streamflow will have high downward leakage. Additional components of the
 

water budget are stream inflow, discussed earlier, and recharge to the
 

surficial layer caused by Floridan aquifer system withdrawals, estimated
 

as the total withdrawal from the Floridan aquifer system for irrigation
 

and heat pump supply, from table 2.
 

The components of inflow and outflow for the entire Volusia County
 

surficial layer are estimated as the areally—weighted averages of each
 

inflow and outflow component in table 4. The annual water budget is thus
 

53 inches rainfall, 1 inch upward leakage from the Floridan aquifer sys­


tem, 0.5 inch recharge from Floridan aquifer system withdrawals, and 0.5
 

inch stream inflow, counterbalanced with 39 inches evapotranspiration,
 

11 inches stream outflow, and 5 inches downward leakage to the Floridan
 

aquifer system. As discussed earlier, these water—budget values are sub­


ject to considerable error.
 

Floridan Aquifer System
 

The purpose of this section is to assemble a water budget of the
 

Floridan aquifer system in Volusia County. If tranamissivity and poten­


tiometric surface of the Floridan aquifer system are known, some of the
 

recharge (inflow) rates previously estimated may be tested. Spring dis­


charge rates are also used to
 

38
 

test these recharge estimates. Then, these tested recharge and discharge rates are placed
 

into a budget of the Floridan aquifer system along with estimates of horizontal inflow and
 

outflow rates derived from the transmissivity estimates.
 

The equation for the water budget of the Floridan aquifer system is a
 

modified version of equation 1:
 

LI +HI = LO +HO +P +FW +SPG (2)
 

where
 

RI = horizontal ground—water inflow;
 

HO = horizontal ground—water outflow;
 

P = pumpage;
 

FW = flowing well discharge;
 

SPG = spring discharge;
 

and other terms are as previously defined.
 

Specific Capacities
 

The specific capacity of a well is related to transmissivity of the penetrated aquifer.
 

The specific capacity is the ratio of pumping rate from a well to the drawdown in the well.
 

Because transmissivity is a characteristic of the entire aquifer thickness, and because most
 

wells penetrate only a fraction of that thickness, it is necessary to adjust data to esti­


mate the specific capacity of fully—penetrating wells. This may be done by dividing the spe­


cific capacity of each well by the length of well that is open to the aquifer, then
 

multiplying this ratio by the aquifer thickness to estimate the specific capacity
 

that would have been obtained had the well penetrated the entire thickness of the
 

aquifer. It is assumed that the aquifer contributes water to the well uniformly from
 

top to bottom.
 

Ratios of specific capacities to lengths of open hole are shown in figure 23.
 

All wells shown are at least 6 inches in diameter and all but one are used for public supply
 

or irrigation. Although these values vary, it is possible to discern general areal trends.
 

Five physiographic areas and the average ratio from figure 23 are as follows: 
 

Average ratio of specific capacity
 

Area to length of open hole, in gallons
 

per minute per foot per foot
 

Crescent City Ridge 


De Land Ridge 


Talbot Terrace and Rima 


Ridge
 

Pamlico Terrace and 


Atlantic Coastal Ridge
 

Coastal areas 


0.3
 

1.9
 

0.5
 

15
 

1.3
 

40
 

------

-------------

-----------------------------------------------

If it is assumed that the Floridan aquifer system is an isotropic, homogeneous, and
 

nonleaky aquifer, then the specific capacity of wells fully penetrating the aquifer
 

is related to transmissivity by the following:
 

Q- ≈ (4πT) - sw t
 2.30log2.25T 


rw2s 


(from Lohman, 1979, p. 52) (3)
 

where
 

T = transmissivity (feet squared per day);
 

S = storage coefficient (dimensionless);
 

Q = discharge rate from pumping well (cubic feet per day);
 

t = time after discharge started (days);
 

sw = drawdown at production well, (feet); and 
 

rw = radius of production well, (feet).
 

The equation shows that specific capacity, Q/sw is nearly proportional to T at a
 

given value of t, but gradually diminishes as t increases by the amount l/log10t.
 

The value of transmissivity calculated for a given test is sensitive to specific
 

capacity but relatively insensitive to values of t, rw , and S. Some error is built
 

into this analysis because leakage is not considered and because some of the assump­


tions about the aquifer’s properties may not be accurate. If it is assumed that t =
 

0.03 day, that rw = 1 foot, that S = 0.0005, and that the aquifer thickness is that
 

of the upper permeable zone of the Floridan aquifer system as defined by Miller
 

(1981), which is 300 feet in Volusia County, then the relation between the ratio
 

derived above and transmissivity is as follows:
 

Average ratio of specific capacity
 

to length of open hole, in gallons Transmissivity,
 

per minute per foot per foot in ft2/d
 

0.5 35,000
 

1.0 74,000
 

1.5 114,000
 

Testing Estimates of Flow in the Floridan Aquifer System
 

Against Recharge Estimates
 

The flow within an aquifer may be compared to the net recharge (leakage) esti­


mated for areas upgradient to determine if estimates of recharge rates are realis­


tic. Figure 24 shows four areas for which these comparisons are made. The flow rates
 

from areas 2, 3, and 4 are measured discharges from springs, and that of area 1 is
 

determined from hydraulic gradient and transmissivity.
 

If the head gradient across the outflow boundary of a recharge area is known and
 

the transmissivity at that boundary is also known, then the average recharge rate
 

for the area may be calculated. Considering area 1 as an area bounded by a ground—
 

water divide on the west and by an outflow line on the
 

42
 

east, the outflow line may be subdivided into segments A through J for the purpose
 

of calculating outflow. The flow through each segment may be calculated from the
 

expression:
 

Q= T I L (4)
 

where
 

Q = rate of flow perpendicular to a potentiometric contour, in cubic feet per
 

day;
 

T = transmissivity of the aquifer in feet squared per day;
 

I = hydraulic gradient approximated as the change in head between the two
 

contours, in feet, divided by the distance between the two contours, in
 

feet; and
 

L = width of the segment midway between contours, in feet.
 

Because this outflow line is on the Rima Ridge and the Talbot Terrace, where
 

the average ratio of specific capacity to length of open hole is 0.5 gallons per
 

minute per foot per foot, the average transmissivity is estimated as 35,000 ft2/d.
 

Total flow through segments A through J is thus 31.4 ft3/s. Because the area upgra­


dient is 99 mi , this rate corresponds to an average net recharge inflow to the
 

Floridan aquifer system of 4.3 in/yr.
 

Area 1 consists of 6 percent areas of artesian flow, 92 percent nonridge areas
 

without artesian flow, and 2 percent ridge areas having surface drainage. The
 

weighted—average net recharge calculated using table 4 is 3.6 in/yr, which compares
 

reasonably with the 4.3 in/yr calculated from flow in the Floridan aquifer system.
 

Area 2, which is the drainage area of Ponce de Leon Springs, consists of 38 per-


cent areas of artesian flow, 19 percent nonridge areas without artesian flow, 21
 

percent ridge areas with surface drainage, and 22 percent ridge areas in closed
 

basins. Using the estimates in table 4, the weighted—average net recharge is 5.3 in/
 

yr. For a 76—square—mile area, total flow is 30 ft3/s. This is equal to the measured
 

long—term average discharge of Ponce de Leon Springs.
 

The drainage area of Blue Springs is divided into areas 3 and 4 so that the flow
 

which originates in Volusia County may be separates from that which originates pre-


dominantly in Lake County. Area 3 is 138 mi consisting of 1 percent areas of arte­


sian flow, 29 percent nonridge areas without artesian flow, 12 percent ridge areas
 

having surface drainage, and 58 percent ridge areas in closed basins. The weighted—
 

average recharge, 12.8 in/yr, is equivalent to flow of 130 ft3/s. Most of the 59 mi
 

in area 4 are in Lake County, but 7 mi areridge areas in closed basins in Volusia
 

County. This latter area yields 9.4 ft3/s of recharge whereas the remaining area
 

yields only 4.7 ft3/s because most of it is an area of artesian flow in the St. Johns
 

River basin. The net recharge calculated for areas 3 and 4 is thus 144 ft3/s, which
 

compares reasonably to the long—term average discharge of Blue Springs, 161 ft3/s.
 

It is assumed in this analysis that all recharge is discharged by the local
 

44
 
spring. It is possible that some of this recharged water is moving downward to more distant
 

points of discharge, or that water recharged outside of the study area is entering this
 

ground—water basin.
 

Water Budget of the Floridan Aquifer System
 

Table 5 gives the estimated flow budget of the Floridan aquifer system in Volusia 

County. Leakage figures were derived from the rates given in table 4 which have been substantiated by analyses of flow in the Floridan aquifer system. The figure for spring discharge is the sum of discharges from Blue Springs, Ponce de Leon Springs, and 8 ft3/s for two 

small springs near Lake Monroe. The discharge from flowing wells is an estimate. Pumpage is 

equal to the 1980 water—use rate. The horizontal flow into and out of Flagler County and the 

horizontal flow into the Atlantic Ocean were calculated from the equation Q =T I L. Finally, 

the horizontal inflow and outflow at “other boundaries” was estimated. These boundaries are 

the east shore of Lake George and Lake Harney, the north shore of Lake Monroe, and the Lake 

County, Seminole County, and Brevard County boundaries. These flow rates through “other 

Table 5.--Estimated water budget of the Floridan aquifer system in Volusia County
 

Inflow
 

Downward leakage
 

Horizontal inflow:
 

From Flagler County
 

From other boundaries
 

Total
 

Outflow
 

Upward leakage
 

Spring discharge
 

Flowing—well discharge
 

Pumpage
 

Horizontal outflow:
 

To Atlantic Ocean
 

To Flagler County
 

To other boundaries 
 

Total
 

Cubic feet Inches
 

per second per year
 

460 5.2
 

20 0.23
 

50 0.57
 

530 6.0
 

Cubic feet Inches
 

per second per year
 

100 1.1
 

190 2.1
 

20 0.23
 

100 1.1
 

30 0.34
 

10 0.11
 

80 1.0
 

530 6.0
 

45
 
boundaries” were calculated as residuals to the other components. The estimated
 

annual water budget of the Floridan aquifer system in Volusia County thus consists
 

of 5 inches downward leakage inflow, 1 inch upward leakage outflow, 1 inch horizon­


tal inflow, 1.5 inches horizontal outflow, 2.5 inches discharge from springs and
 

flowing wells, and 1 inch pumpage. These water—budget figures are subject to consid­


erable error. The largest component of this budget, leakage, was derived as a resid­


ual in the budget of the surficial aquifer, and that budget was constructed from
 

other estimates.
 

CONCEPTS OF BRACKISH WATER OCCURRENCE AND MOVEMENT
 

Baseline Salinity
 

Chloride concentration is used in this report as the index of salinity because
 

chloride ions make up the largest component of the total salinity of seawater and
 

because chloride analysis is a relatively simple laboratory determination. Most nat­


urally occurring waters have chloride in some amount. For this report, water having
 

a chloride concentration less than 50 milligrams per liter (mg/L) is considered
 

freshwater. If the concentration is about 19,000 mg/L, the water has a salt concen­


tration close to that of the ocean, and is considered saltwater. Waters having chlo­


ride concentrations intermediate between these extremes may be considered brackish.
 

Fresh ground water in Volusia County contains some of the salts present in the
 

ocean. This mixture probably exists because salt—laden aerosols from the ocean pre­


cipitate on land. Ground water also contains constituents dissolved from the rocks
 

and the soil.
 

Values of chloride concentration in water from individual sites not exhibiting
 

intrusion may vary because of seasonal effects. Figure 25 shows variations in the
 

chloride concentration in water from freshwater wells. Most fresh ground water in
 

Volusia County has a chloride concentration exceeding 10 mg/L and varying within a
 

range of 10 mg/L. Figure 26 shows variations in chloride concentrations in brackish
 

water wells. The records shown, with the exception of the record for 911—059—02,
 

exhibit changes caused by seasonal fluctuations, as opposed to changes caused by a
 

trend. Many records vary in such a way that the maximum is more than twice as much
 

as the minimum.
 

Chloride Concentration Change Ratio
 

The terms “brackish water movement” or “intrusion” used herein, refer to a sig­


nificant increase in chloride concentration, with time, at given monitoring sites.
 

Intrusion may be assessed by comparing chloride concentrations in water from wells
 

during 1951—57 with data collected from the same veils during 1977—82 as follows:
 

46
 


------------------

-------------------------- F C( n – Ct) chloride concentration = - (5) 

change ratio Cn + Ct

- 2 


where 


Cn = chloride concentration now (1977-82), in milligrams
 

per liter;
 

Ct = chloride concentration then (1951—57), in milligrams
 

per liter; and
 

F(Cn-Ct) = Cn-Ct-lO, if Cn—Ct is greater than +10
 

= Cn-Ct+lO, if Cn-Ct is less than —10
 

= zero, if Cn—Ct falls in the —10 to +10 range
 

This ratio is more meaningful than a simple ratio of concentration change
 

over average concentration because the latter ratio would be the same for a
 

change of 10 to 20 mg/L as it would for a change of 1,000 to 2,000 mg/L, which
 

is much more significant.
 

If the chloride concentration change ratio exceeds +0.5 or falls below
 

—0.5, then the change is probably larger than that which can be attributed to
 

seasonal variations. Changes thus described may be evidence of intrusion or
 

freshening.
 

Physical Nature Freshwater-Saltwater Interface
 

In coastal aquifers within Volusia County, the freshwater is bounded by
 

saltwater laterally and vertically. The theoretical altitude of the freshwater—
 

saltwater interface may be calculated using the Ghyben—Herzberg principle as
 

modified by Hubbert (1940). This principle states that when freshwater in a
 

coastal aquifer is in equilibrium with the underlying saltwater, the altitude
 

of the interface between them is —40 times the head of the freshwater system
 

immediately above the interface. Because the freshwater head immediately above
 

the interface differs from the head that is measured in wells that tap the
 

upper parts of the aquifer, and because the saltwater system is usually not
 

static, estimates of the altitude of the interface are subject to error. It is
 

reasonable to assume, though, that the position of the interface becomes lower
 

as the measured water level in the upper part of the aquifer increases.
 

Figure 27a shows that the transition from freshwater to saltwater is a
 

zone of mixing which contains brackish water. This transition zone is formed
 

because of mixing caused by water—level fluctuations and dispersion. Generally,
 

the thickness of this zone becomes greater as the vertical component of ground—
 

water flow increases. Figure 27b shows, conceptually, the movement of the tran­


sition zone caused by pumping.
 

49 

WATER BUDGET 

BRACKISH WATER IN THE SURFICIAL AQUIFER
 

Present Distribution
 

Most ot the surficial aquifer in Volusia County contains freshwater. Figure 28 shows that the bar­


rier island is generally the only area where chloride concentrations exceed 250 mg/L. Brackish water
 

occurs in coastal areas and, to a lesser extent, in the St. Johns River valley area. The areal distri­


bution of chloride concentrations shown in the figure was obtained from samplings of approximately 70
 

wells. Most wells sampled are in coastal areas.
 

In freshwater zones of the surficial aquifer, the water is considerably less mineralized than water
 

in the freshwater zones of the Floridan aquifer system. Most of the freshwater in the surficial aquifer
 

is a calcium bicarbonate—type water, although sodium and chloride are locally prevalent. Figure 29 shows
 

average ionic compositions for eight surficial—aquifer wells in the central Volusia County area, where
 

the dissolved solids concentration of water from the surficial aquifer is approximately one—third of
 

that from the upper part of the Floridan aquifer system in the same area. The brackish water in the
 

surficial aquifer is a sodium chloride—type water that is less mineralized than the brackish water in
 

the Floridan aquifer system at the same location. Sodium chloride and calcium bicarbonate concentrations
 

are less in the surficial aquifer than in the Floridan aquifer system.
 

Comparison of Past and Present
 

Chloride—concentration change ratios for 10 surficial aquifer wells are shown in figure 28. Depths
 

of these wells are 12 to 45 feet. Four ratios are above +0.5, one is below —0.5, and five are between —
 

0.5 and +0.5. The four that exceed +0.5 are on the barrier island north of Ormond Beach and indicate
 

that intrusion is apparently occurring there. The meaning of the one value below —0.5 is somewhat dubi­


ous because the well had a measured depth of only 14 feet in 1981 versus the 40 feet reported depth. The
 

five wells for which the chloride concentration change ratio was insignificant (between —0.5 and +0.5)
 

are all located in areas where the surficial aquifer has freshwater.
 

It is apparent that intrusion is occurring in the surficial aquifer on the barrier island. Unfor­


tunately, no surficial aquifer veils sampled during 1951—57 are currently available for resampling south
 

of Ormond Beach on the barrier island. This is because the few that were sampled then were destroyed or
 

covered before this study.
 

BRACKISH WATER IN THE FLORIDAN AQUIFER SYSTEM 

Present Distribution
 

Figure 30 shows the distribution of brackish water in the upper part of the Floridan aquifer system
 

derived from sampling approximately 250 wells during 1977—82. Depths of these wells are 50 to 400 feet.
 

The Floridan
 

51
 




WATER BUDGET 

Average ion concentrations of water from Floridan aquifer system wells in three different parts of the
 

Volusia County ground—water system are shown in figure 32, and the locations of the wells used are in 
 

figure 33. The three water types shown are the brackish water in the St. Johns River area, the brackish
 

water of the coastal areas, and the freshwater in between. All three have a calcium bicarbonate “back-


ground” caused by dissolution of the limestone that makes up the aquifer. This dissolution causes fresh-


water in the Floridan aquifer system to be more mineralized than freshwater in the surficial aquifer. 
 

Superimposed upon this calcium bicarbonate background is a mixture of the salts found in seawater. This 
 

mixture is very dilute in the freshwater in central Volusia, (calcium bicarbonate—type water) and is 
 

stronger for the two brackish—water areas (sodium chloride—type water). The ratio of calcium ions to 
 

bicarbonate ions is about 1 for fresh ground water but is noticeably higher for brackish water in the 
 

Floridan. The reason for this may be that cation exchange is taking place. The sodium and magnesium ions 
 

in the brackish waters are switching places with calcium ions in the limestone, thus creating a higher 
 

calcium to bicarbonate ratio in the water.
 

The ratio of sodium to chloride ions in freshwater in central Volusia, 1.00, is equal to that of
 

table salt and that of brackish areas is nearly that of seawater, 0.85. The ratio of sodium to chloride
 

in brackish Floridan aquifer system water is actually slightly smaller than that of seawater because of
 

the cation exchange previously mentioned.
 

The sulfate concentration in coastal brackish ground water is disproportionately low compared to
 

the concentration in the St. Johns River basin brackish ground water and seawater. The ratio of sulfate
 

to chloride ions is 0.042 for the former type and 0.10 for the latter two water types. The reason for
 

these differences is unclear; a possibility is that sulfate reduction is occurring preferentially in
 

coastal ground water.
 

Comparison of Past and Present
 

Chloride concentrations in the past were compared with recent concentrations to determine brackish
 

water trends in the Floridan aquifer system. This analysis is separated into two parts——one for wells
 

that have not been used for public supply and another for wells that have been used. The latter category
 

includes abandoned public—supply wells. Public—supply wells are discussed separately because results
 

found for public—supply wells were markedly different from results found for other wells.
 

Nonpublic—Supply Wells 
 

Ranges of chloride—concentration change ratios for 154 veils are shown in figure 34. Most wells
 

sampled are in areas where the Floridan aquifer system contains brackish water. If change ratios indi­


cating a significant change are those above or equal to +0.5 and below or equal to —0.5, then 10 wells
 

showed a significant increase and 11 showed a significant decline. Neither group exhibited distinct
 

areal trends. A few generalizations may be made, however: five
 

56
 



wells showing a significant increase are in the coastal area from Daytona Beach
 

to north of Ormond Beach; three wells showing significant increases are in the
 

Ponce de Leon Springs area; and five wells showing a significant decline are in
 

the inland areas from Oak Hill to New Smyrna Beach. All of these groups, how-


ever, are intermixed with wells that did not exhibit significant changes.
 

Wells for which chloride—concentration change ratios were within the —
 

0.5 to +0.5 range likewise did not show areal patterns.
 

The significant increases in chloride concentration in the water from five
 

wells in the coastal area of Ormond Beach and Daytona Beach may be associated
 

with ground—water withdrawals in northeast Volusia County. Figures 10 and 12
 

indicate that many wells exist there and figure 18 shows large drawdown in the
 

area.
 

The most marked increase in chloride concentration in a nonpublic—supply
 

well is in well 911—059—02 on the barrier island in Daytona Beach. This well
 

showed a gradual increase from 110 mg/L in 1956 to 580 mg/L in 1979, followed
 

by a jump to 1,400 mg/L in 1981 (fig. 26). Well 911—059—02 is one of the five
 

wells in northeast Volusia County which exhibited significant changes (fig.
 

34).
 

Twenty—two irrigation wells were resampled in January 1983, as part of an
 

intrusion monitoring network that was suggested by Rutledge, (1982). Table 6
 

gives chloride concentrations in the wells resampled. Of the 22 wells, only one
 

showed a marked change. Well 907—122—01 yielded water with a chloride concen­


tration of 280 mg/L in 1980 and 500 mg/L in 1983. It is noteworthy that this
 

well is in the area of Ponce de Leon Springs, near the three wells previously
 

mentioned that exhibited chloride—concentration change ratios greater than
 

+0.5 (fig. 34).
 

Generally, there is little evidence that intrusion is occurring uniformly
 

over large areas in the Floridan aquifer system in Volusia County. This means
 

that if intrusion is taking place, it is local upconing of brackish water. Such
 

a movement would tend to be noticeable from samplings of wells that are deeper,
 

are pumped a greater amount of the time, and are pumped at higher rates.
 

Public—Supply Wells
 

For the purpose of evaluating chloride—concentration change ratios for
 

public—supply wells, samplings during three periods of 1982 are compared to
 

previous samplings. Figures 35, 36, and 37 show the ratios thus determined dur­


ing March—April, August, and December 1982, respectively. Of the 14 wells sam­


pled during March—April 1982, 9 exhibited chloride concentration change ratios
 

that equaled or exceeded +0.5. The remaining 5 ratios are in the range of —0.5
 

to +0.5. Of the 23 wells sampled in August 1982 (fig. 36), 8 yielded ratios
 

that equaled or exceeded +0.5, and the remainder fell in the range of
 

—0.5to +0.5. Of the 27 wells sampled in December 1982 (fig. 37), 5 yielded 

ratios that equaled or exceeded +0.5 and 4 yielded ratios below or equal to 

—0.5. Increases in chloride concentration occur primarily during the dry 

60 
Table 6.--Chloride concentration in water from wells in the monitoring network 

suggested on the northwest Volusia County report. 

DATE OF CHLORIDE 

SAMPLING (YR- TIME OF CONCENTRATION 

STATION NO. LOCAL NO. AND WELL NAME MO-D) SAMPLING (MG/L) 

290532081213501 90512101 

290532081213501 90512101 

290532081213501 90512101 

290532081213501 90512101 

290532081213501 90512101 

290538081213501 90512102 

290538081213501 90512102 

290538081213501 90512102 

290538081213501 90312102 

290538081213501 90512102 

290538081213501 90512102 

290538081213501 90512102 

290538081213501 90512102 

290538081213501 90512102 

290512081213801 90512111 

290512081213801 90512111 

290512081213801 90312111 

290635081202101 90612005 

290635081202101 90612005 

290646081213701 90612101 

290646081213701 90612101 

290646081213701 90612101 

290646081213701 90612101 

290646081213701 90612101 

290646081213701 90612101 

290646081213701 90612101 

290642081214001 90612102 

290642081214001 90612102 

290642081214001 90612102 

290612081214101 90612107 

290612081214101 90612107 

290612081214101 90612107 

290612081214101 90612107 

290612081214101 90612107 

290612081214101 90612107 

290612081214101 90612107 

290612081214101 90612107 

290612081214101 90612107 

290613081213001 90612108 

290613081213001 90612108 

290613081213001 90612108 

290613081213001 90612108 

290613081213001 90612108 

290804081215601 90712101 

290804081215601 90712101 

290804081215601 90712101 

290804081215601 90712101 

290804081215601 90712101 

290804081215601 90712101 

290804081215601 90712101 

290804081215601 90712101 

290804081215601 90712101 

290804081215601 90712101 

C.F. GREENS #1 WELL, GLENW000 

C.F. GREENS #1 WELL, GLENW000 

C.F. GREENS #1 WELL, GLENW000 

C.F. GREENS #1 WELL, GLENW000 

C.F. GREENS #1 WELL, GLENW000 

C.F. GREENS DEEP WELL, GLENW00D 

C.F. GREENS DEEP WELL, GLENW00D 

C.F. GREENS DEEP WELL, GLENW00D 

C.F. GREENS DEEP WELL, GLENW00D 

C.F. GREENS DEEP WELL, GLENW00D 

C.F. GREENS DEEP WELL, GLENW00D 

C.F. GREENS DEEP WELL, GLENW00D 

C.F. GREENS DEEP WELL, GLENW00D 

C.F. GREENS DEEP WELL, GLENW00D 

BOOKERS IRR. WELL, GLENWOOD 

BOOKERS IRR. WELL, GLENWOOD 

BOOKERS IRR. WELL, GLENWOOD 

C. RICHARDS0N'S #24 WELL, DELEON SPGS 

C. RICHARDS0N'S #24 WELL, DELEON SPGS 

16S29E W.WARDS WELL,W DELEON SPRINGS 

16S29E W.WARDS WELL,W DELEON SPRINGS 

16S29E W.WARDS WELL,W DELEON SPRINGS 

16S29E W.WARDS WELL,W DELEON SPRINGS 

16S29E W.WARDS WELL,W DELEON SPRINGS 

16S29E W.WARDS WELL,W DELEON SPRINGS 

16S29E W.WARDS WELL,W DELEON SPRINGS 

LAWRENCE WELL, DELEON SPRINGS 

LAWRENCE WELL, DELEON SPRINGS 

LAWRENCE WELL, DELEON SPRINGS 

HAGSTROM DSL WELL, N. GLENW00D 

HAGSTROM DSL WELL, N. GLENW00D 

HAGSTROM DSL WELL, N. GLENW00D 

HAGSTROM DSL WELL, N. GLENW00D 

HAGSTROM DSL WELL, N. GLENW00D 

HAGSTROM DSL WELL, N. GLENW00D 

HAGSTROM DSL WELL, N. GLENW00D 

HAGSTROM DSL WELL, N. GLENW00D 

HAGSTROM DSL WELL, N. GLENW00D 

LUCAS IRRIG WELL, S OF DELEON SPGS 

LUCAS IRRIG WELL, S OF DELEON SPGS 

LUCAS IRRIG WELL, S OF DELEON SPGS 

LUCAS IRRIG WELL, S OF DELEON SPGS 

LUCAS IRRIG WELL, S OF DELEON SPGS 

12” FLOW W OF DELEON SPRINGS 

12” FLOW W OF DELEON SPRINGS 

12” FLOW W OF DELEON SPRINGS 

12” FLOW W OF DELEON SPRINGS 

12” FLOW W OF DELEON SPRINGS 

12” FLOW W OF DELEON SPRINGS 

12” FLOW W OF DELEON SPRINGS 

12” FLOW W OF DELEON SPRINGS 

12” FLOW W OF DELEON SPRINGS 

12” FLOW W OF DELEON SPRINGS 

61 

79—02—10 816 142 

79—11—30 600 110 

80--02--05 550 130 

80—03—03 635 65 

83—01—18 505 120 

78—12—14 1600 500 

79—01—23 —— 665 

79—02—10 535 655 

79—02—10 818 650 

79—12--27 630 360 

80—01—02 555 800 

80—02—05 600 670 

80—03—03 640 620 

83—01—18 500 360 

80—01—02 820 64 

80—03—03 655 58 

83—01—18 515 46 

79--12--27 700 31 

83--01--18 615 30 

78—12—18 1000 930 

79—01—23 —— 790 

79—02—10 608 920 

79—02—10 758 880 

79—12—01 700 790 

80—02—05 635 700 

80—03—03 610 640 

79—12—27 610 430 

80—03—03 620 400 

83—01—18 550 380 

78—12—18 915 450 

79—01—23 —— 490 

79—02--10 603 478 

79—02—10 804 480 

79—12—01 645 470 

79—12—27 615 400 

80—01—02 540 500 

80—03—03 625 440 

83—01—18 525 450 

78—12—18 1015 710 

79—02—10 556 798 

79—02—10 808 792 

80—02--05 630 710 

83—01—18 535 660 

57—04—29 —— 390 

66—01—20 —— 670 

79—06—15 1400 438 

79—09—10 1340 678 

79—12—10 1500 810 

80—02—05 700 780 

81—12—15 1310 510 

82—04—14 1020 720 

83—06—02 900 830 

84--05—03 905 810 
----

Table 6.--Chloride concentrations in water from wells in the monitoring network 

suggested om the northwest Volusia County report--Continued 

DATE OF CHLORIDE 

SAMPLING TIME OF CONCENTRATION 

STATION NO. LOCAL NO. AND WELL NAME (YR—MO—D) SAMPLING (MG/L) 

290752081220901 90712102
 

290752081220901 90712102
 

290752081220901 90712102
 

290752081220901 90712102
 

290752081220901 90712102
 

290752081220901 90712102
 

290752081220901 90712102
 

290752081220901 90712102
 

290737081220301 90712201
 

290737081220301 90712201
 

290815081194801 90811902
 

290815081194801 90811902
 

290815081194801 90811902
 

290849081202601 90812004
 

290849081202601 90812004
 

290849081202601 90812004
 

290849081202601 90812004
 

290849081202601 90812004
 

290910081202801 90912003
 

290910081202801 90912003
 

290910081202801 90912003
 

290917081222201 90912203
 

290917081222201 90912203
 

290917081222201 90912203
 

290917081222201 90912203
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081231601 90912301
 

290959081283501 90912801
 

291017081235001 91012006
 

291017081235001 91012006
 

8"FLOW WELL W.OF DELEON SPRINGS 

8"FLOW WELL W.OF DELEON SPRINGS 

8"FLOW WELL W.OF DELEON SPRINGS 

8"FLOW WELL W.OF DELEON SPRINGS 

8"FLOW WELL W.OF DELEON SPRINGS 

8"FLOW WELL W.OF DELEON SPRINGS 

8"FLOW WELL W.OF DELEON SPRINGS 

8"FLOW WELL W.OF DELEON SPRINGS 

HAGSTROM IRRIG WELL, W OF DELEON SPGS 

HAGSTROM IRRIG WELL, W OF DELEON SPGS 

FG INTERNAT #1 WELL, DELEON SPGS 

FG INTERNAT #1 WELL, DELEON SPGS 

FG INTERNAT #1 WELL, DELEON SPGS 

HCBLICK #4 WELL, E OF DELEON SPGS 

HCBLICK #4 WELL, E OF DELEON SPGS 

HCBLICK #4 WELL, E OF DELEON SPGS 

HCBLICK #4 WELL, E OF DELEON SPGS 

HCBLICK #4 WELL, E OF DELEON SPGS 

CRIBB'S IRRIG WELL, N OF DELEON SPGS 

CRIBB'S IRRIG WELL, N OF DELEON SPGS 

CRIBB'S IRRIG WELL, N OF DELEON SPGS 

DAWSON BRN FLOW WELL SE OF BARBERVILLE 

DAWSON BRN FLOW WELL SE OF BARBERVILLE 

DAWSON BRN FLOW WELL SE OF BARBERVILLE 

DAWSON BRN FLOW WELL SE OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

DAIRY FLOW WELL #1, SW OF BARBERVILLE 

B.F. TURNER WELL, SR4O, NR EMPORIA 

BLACKWELDER N WELL, DELEON SPGS 

BLACKWELDER N WELL, DELEON SPGS 

62
 

57—04—30 —— 7200 

79—09—10 1350 4275 

79—12—10 1515 4800 

80—02—05 0650 4700 

81—12—15 1340 3800 

82—04--14 1030 4000 

83—06—02 0900 4500 

84—05—03 0850 4200 

80—05—13 1030 280 

83—01—18 0600 500 

80—01—02 0640 8.7 

80—03—03 0750 11 

83—01—18 0625 9.8 

79—06—21 1600 266 

79—12—05 1530 230 

79—12—05 1630 230 

80—03—03 0855 260 

83—01—18 0640 274 

79—12—27 0730 10 

80—03—03 0915 10 

83—01—18 0655 9.1 

56—04—23 —— 14 

66—01—20 11 

79—12—05 1600 11 

82—04—14 1000 11 

53—11—06 —— 326 

66—09—13 —— 478 

67—01—03 1530 422 

67—02—27 0930 445 

67—05—01 1145 400 

67—07—10 1215 425 

67—09—11 1025 425 

67—11—01 1145 430 

68—01—04 1000 435 

68—03—08 1110 430 

68—05—03 1030 370 

68—10—25 0850 445 

69—05—06 1110 450 

70—09—26 —— 455 

70—11—04 —— 455 

72—05—10 1900 300 

72—09—06 1115 450 

79—12—10 1430 470 

80—01—23 1100 470 

81—12—16 1400 450 

82—04—14 0930 440 

83—08—04 1715 450 

83—08—04 1715 450 

79—02—10 0730 15 

79—02—01 0725 14 

83—01—18 0700 11 
Table 6.--Chloride concentrations in water from wells in the monitoring network 

suggested in the northwest Volusia County report--Continued 

DATE OF CHLORIDE 

SAMPLING (YR- TIME OF CONCENTRATION 

STATION NO. LOCAL NO. AND WELL NAME MO-D) SAMPLING (MG/L) 

291112081282601 91112802
 

291112081282601 91112802
 

291111081291401 91112915
 

291111081291401 91112915
 

291216081215601 91212101
 

291208081292501 91212906
 

291426081224001 91412205
 

291422081254701 91412505
 

291422081254701 91412505
 

291422081254701 91412505
 

291435081255301 91412509
 

291452081261701 91412610
 

291452081261701 9141261C
 

291454081291101 91412903
 

291522081265201 91512611
 

291522081265201 91512611
 

291525081260601 91512619
 

291525081260601 91512619
 

291507081290601 91512903
 

291507081290601 91512903
 

291507081290601 91512903
 

291508081302801 91513001
 

291508081302801 91513001
 

291508081302801 91513001
 

291508081302801 91513001
 

291621081304901 91613002
 

291724381275701 91712703
 

291724381275701 91712703
 

291715081281801 91712801
 

291715081281801 91712801
 

291838081280601 91812803
 

291838081280601 91812803
 

291838081280601 91812803
 

291838081280601 91812803
 

291834081281101 91812804
 

291834081281101 91812804
 

291834081281101 91812804
 

291834081281101 91812804
 

291910081312401 91913101
 

291910081312401 91913101
 

RICHARDSON’S #13 WELL, EMPORIA 

RICHARDSON’S #13 WELL, EMPORIA 

MCCOLLOUGH EMPOR. RD WELL, EMPOR. 

MCCOLLOUGH EMPOR. RD WELL, EMPOR. 

STRWMD TEST WELL, SR40, E OF BARBERVILE 

S.SMITPH HARP+PET. RD SW WELL, EMPORIA 

UNDERHILL 10” WELL, NR BARBERVILLE 

14S28E36 TAYLOR’S MISERY WELL, PIERSON 

14S28E36 TAYLOR’S MISERY WELL, PIERSON 

14S28E36 TAYLOR’S MISERY WELL, PIERSON 

R.JONES 8” WELL,MISERY+WASH. RD,PIERSON 

R.JONES WELL N OF WASH. ST, PIERSON 

R.JONES WELL N OF WASH. ST, PIERSON 

T.TAYLCR CARLYLE WELL, W. PIERSON 

WORTHINGTON PINE ST WELL, NE PIERSON 

WORTHINGTON PINE ST WELL, NE PIERSON 

CARTER’S IRRIG WELL. NE PIERSON 

CARTER’S IRRIG WELL. NE PIERSON 

BRADDOCK WELL, W OF WASH RD, PIERSON 

BRADDOCK WELL, W OF WASH RD, PIERSON 

BRADDOCK WELL, W OF WASH RD, PIERSON 

SJRWMD WELL 2 MI W OF PIERSON 

SJRWMD WELL 2 MI W OF PIERSON 

SJRWMD WELL 2 MI W OF PIERSON 

SJRWMD WELL 2 MI W OF PIERSON 

14S28E19 KELLY'S 2”WELL NW OF PIERSON 

M.SMITH L.B.C. RD 8” WELL, SEVILLE 

M.SMITH L.B.C. RD 8” WELL, SEVILLE 

J.C. MEW WELL AT SEVILLE, FL. 

J.C. MEW WELL AT SEVILLE, FL. 

W.COLMANS COWART RD WELL, SE SEVILLE 

W.COLMANS COWART RD WELL, SE SEVILLE 

W.COLMANS COWART RD WELL, SE SEVILLE 

W.COLMANS COWART RD WELL, SE SEVILLE 

M.COLMANS COWART RD WELL, SE SEVILLE 

M.COLMANS COWART RD WELL, SE SEVILLE 

M.COLMANS COWART RD WELL, SE SEVILLE 

M.COLMANS COWART RD WELL, SE SEVILLE 

13S27E36 MILLICANS WELL W OF SEVILLE 

13S27E36 MILLICANS WELL W OF SEVILLE 

78—12—14 1115 11 

79—02—10 0755 13 

78--12—13 0940 11 

83—01—18 0940 10 

79—02—39 1310 22 

79—02—10 0800 12 

78—12—15 1310 10 

78—12—08 1445 8 

79—02—10 0705 13 

83—01—l8 0715 8.8 

73—12—14 1330 9 

78—12—20 1315 8.4 

83—01—18 0725 8.9 

83—01—18 0825 9.6 

79—02—10 0635 11 

83—01—18 0800 8.2 

80—01—02 0545 7.9 

83—01—18 0745 7.2 

78—01—l0 0955 8 

79—02—10 0840 12 

83—01—18 0815 7.5 

78—12—20 1210 11 

79—02—09 0950 14 

79—09—27 1445 11 

79—12—18 1530 11 

79—12—18 1600 200 

79—01—29 0800 13 

83--01--18 0920 9.4 

79—09—06 1915 10 

80—01—08 1410 11 

78—11—30 1115 12 

79—01—29 0730 15 

80—01—02 0740 11 

83—01—l8 0850 13 

78—01—11 0820 29 

79—02—10 0555 29 

80—01—02 0745 21 

83--01--18 0900 31 

78—12—20 1350 17 

79—01—29 0845 16 

63
 



seasons when water levels are low and water withdrawals are high. Concentrations
 

decrease temporarily during periods of higher water levels and reduced water use such
 

as December 1982. Figures 38 and 39 show large fluctuations in the chloride concen­


tration of water from public—supply wells.
 

The fact that the water from many public—supply wells has undergone a net wors­


ening over the years is best exemplified by the abandonment of production wells and
 

by the replacement of abandoned wells with new wells in areas of fresher ground
 

water. Figures 40 and 41 show public—supply wells in use in the mid-1950’s and in
 

1982, respectively, for northeast Volusia County. The well fields belonging to the
 

city of Daytona Beach have changed dramatically. In 1954—57, the city was supplied by
 

three sets of wells——one on the barrier island, one near the intersection of U.S. 92
 

and S.R. 5A, and the third north of the airport. In 1982, the first two sets of wells
 

had been abandoned entirely and three of the wells north of the airport had also been
 

abandoned. A new well field near the intersection of Indian Lake Road and U.S. 92 was
 

put into operation in 1982. Pumping stress for the cities of Ormond Beach, Port
 

Orange, and Holly Hill has also shifted toward central Volusia County. A new well
 

field belonging to the city of New Smyrna Beach was installed 7 miles inland of the
 

old well field (figs. 9 and 10) in 1981. The newest wells belonging to the Deltona
 

Corporation are northeast of the older wells (fig. 10), away from the brackish ground
 

water in the St. Johns River area (fig. 30).
 

The table of supplemental data at the back of this report shows chloride concen­


trations in public—supply wells.
 

EFFECTS OF MANAGEMENT ALTERNATIVES ON MOVEMENT OF BRACKISH WATER
 

Surficial Aquifer
 

The movement of brackish water in the surficial aquifer will probably continue on
 

the barrier island. This intrusion is difficult to manage because of lack of control
 

of withdrawals. Reduction of withdrawals during dry seasons may slow the rate of
 

intrusion.
 

Most intrusion in the surficial aquifer is caused by pumping in areas close to
 

brackish water. Little intrusion is therefore likely in mainland areas.
 

Floridan Aquifer System
 

Possible water—management alternatives include minimizing well depths, minimiz­


ing drawdown, installing new wells where the freshwater zone is thickest, increasing
 

head in the freshwater zone using injection wells, and reducing head in the saltwater
 

zone. The best approach may be a combination of the above practices.
 

67
 




Minimizing well depth may be the single most effective step against intrusion. The
 

idea is to keep as much distance as possible between the bottom of the well and the
 

underlying brackish water. Because the thickness of the freshwater zone increases
 

toward central Volusia (fig. 31), the maximum safe well depth also increases in that
 

direction.
 

Numerous management alternatives may reduce drawdown. One of the most practical
 

possibilities is to increase the distance between pumping wells to reduce mutual well
 

interference. Cycling pumping among production wells so that no individual well is
 

pumped for more than a limited time may reduce drawdown. If the number of supply
 

wells per desired water—use rate is maximized, drawdown could be reduced. Two wells
 

1,000 feet apart each pumping 300 gallons per minute will create less drawdown than
 

one well pumping 600 gallons per minute. Although the area of influence will actually
 

be larger for the former situation, the “point drawdown” at the wells would be less.
 

It is this point drawdown that influences the movement of the transition zone below
 

the well the most.
 

Although increasing the penetration of the aquifer tends to reduce draw—down, it
 

may defeat the purpose of avoiding intrusion if well depths become excessive. This
 

concept is illustrated in figure 42. Pumpage is equal for these two conditions, but
 

one well penetrates 200 feet of the aquifer and the other penetrates 400 feet. Assum­


ing that hydraulic properties of the aquifer are uniform, the drawdown in the shallow
 

well is approximately twice the draw—down in the deep well. However, the drawdown
 

below the deeper well near the interface is enough to induce an upward movement of
 

the interface three times greater than the movement under the shallow well. If the
 

interface is induced upward by approximately one—half the original distance between
 

the interface and the bottom of the pumped well, the condition is unstable, and the
 

interface may suddenly move to the bottom of the well (Bouwer, 1978).
 

If all other things remain equal, the best locations for public—supply wells are
 

areas where the potentiometric surface was highest during times of no pumping because
 

these areas are characterized by maximum thickness of the freshwater zone. Figure 31
 

shows that the maximum thickness of the zone containing fresh or slightly brackish
 

water is located beneath the Talbot Terrace (fig. 1). Generally, if a well is
 

installed in this area, there will be a thicker safety zone between the bottom of the
 

well and the transition zone. Unfortunately, the transmissivity of the Floridan aqui­


fer system under the Talbot Terrace may not be as high as it is elsewhere, so greater
 

drawdown may occur there.
 

Injection wells may be used to increase hydraulic head in the freshwater zone and
 

control intrusion. This would involve injection of storm runoff or tertiary—treated
 

sewage, and therefore would require that steps be taken to avoid pollution.
 

Reducing hydraulic head in the saltwater zone below production wells may be an
 

effective way of controlling intrusion, but is expensive relative to other methods.
 

This method would involve installing deep wells open to
 

72
 

saltwater zones and sealed tightly from freshwater zones. These deeper wells would be
 

pumped continuously to reduce saltwater head and the water would be discharged into
 

natural saltwater bodies at the surface.
 

SUMMARY
 

Volusia County is a 1,200—square—mile area in east—central Florida which
 

includes the communities of Daytona Beach, Ormond Beach, New Smyrna Beach, De Land,
 

and Deltona. The area is oriented toward tourism, especially along the coast. The two
 

aquifers underlying the area are the unconfined surficial aquifer and the confined
 

Floridan aquifer system. The surficial aquifer consists of sand, clay, and shell beds
 

of Pleistocene and Holocene age, and the Floridan aquifer system consists of lime-


stone and dolomite of Eocene age. The two aquifers are separated by confining clay
 

beds of Miocene or Pliocene age.
 

Both aquifers contain good quality water in most of Volusia County, but brackish
 

water is present throughout the eastern and western fringes of the county in the
 

surficial aquifer and in the upper zones of the Floridan aquifer system presently
 

tapped by wells. Saltwater is present throughout the county in the relatively
 

untapped lower zones of the Floridan aquifer system. Increased use of water because
 

of development in the fringes has caused intrusion.
 

In 1980, the average ground—water withdrawal in Volusia County was 66 million
 

gallons per day. Ground—water use quadrupled between 1955 and 1980. More than 95 per-


cent of the ground water pumped is from the Floridan aquifer system. All public—sup­


ply wells and most agricultural—irrigation wells are open to this aquifer. The total
 

withdrawals for public supply and agricultural irrigation were 30 and 24 million gal­


lons per day, respectively. Most of the 3 million gallons per day pumpage from the
 

surficial aquifer is used for lawn irrigation.
 

Water levels in Floridan aquifer system wells declined more than 10 feet over an
 

area of 70 square miles from November 1955 to September 1982. This drawdown, which
 

occurred in the areas of Ormond Beach, Daytona Beach, and Port Orange, was caused by
 

pumping. Considerably greater declines were observed for May 1981 because of drought
 

conditions.
 

The annual water budget of the surficial layer consists of 53 inches rainfall, 1
 

inch upward leakage from the Floridan aquifer system, 0.5 inch recharge from Floridan
 

aquifer system withdrawals, and 0.5 inch stream inflow, counterbalanced with 39
 

inches evapotranspiration, 11 inches stream outflow, and 5 inches downward leakage to
 

the Floridan aquifer system.
 

The annual water budget of the Floridan aquifer system consists of 5 inches down-


ward leakage inflow, 1 inch upward leakage outflow, 1 inch horizontal inflow, 1.5
 

inches horizontal outflow, 2.5 inches discharge from springs and flowing wells, and 1
 

inch pumpage.
 

74
 
Chloride concentration, which is used as an index of salinity, may
 

vary at individual sites not exhibiting trends because of seasonal fluc­


tuations. Chloride concentrations in brackish—water wells may fluctuate
 

in such a way that the maximum is more than twice the minimum.
 

Brackish water movement, or intrusion, is apparently occurring in
 

the surficial aquifer on the barrier island in the northeast part of
 

Volusia County. It is likely that intrusion has also occurred in other
 

sections of the barrier island, although this is difficult to ascertain
 

because of the scarcity of long—term chloride concentration data from
 

these areas. The barrier island is generally the only part of the study
 

area where chloride concentrations in the surficial aquifer exceed 250
 

milligrams per liter. Intrusion is likely to continue in the surficial
 

aquifer on the barrier island. Little or no intrusion is occurring in
 

the surficial aquifer in inland areas.
 

There is little evidence that intrusion is occurring uniformly over
 

large areas in the Floridan aquifer system. Most nonpublic—supply wells
 

have not exhibited long—term changes in salinity. Of 154 nonpublic—sup­


ply wells sampled, 10 showed a significant increase and 11 showed a sig­


nificant decline in chloride concentration over time. Significant
 

increases in chloride concentration in water from five such wells in the
 

coastal area of Ormond Beach and Daytona Beach may be associated with
 

ground—water withdrawals in northeast Volusia County.
 

There is upconing or vertical intrusion at sites of public—supply
 

pumping. Public—supply wells are usually deeper, are pumped a greater
 

amount of the time, and are pumped at higher rates than other wells.
 

Intrusion manifests itself as surges that are greatest during times of
 

low rainfall and heavy water use. Many public—supply wells located close
 

to brackish water zones in the fringes of Volusia County have been aban­


doned and replaced by new wells in the central part of the county, where
 

the freshwater zone is thickest.
 

Possible water—management alternatives to intrusion in the Floridan
 

aquifer system include minimizing well depths, minimizing drawdown,
 

installing wells where the freshwater zone is thickest, increasing head
 

in the freshwater zone using injection wells, and reducing head in the
 

saltwater zone. Drawdown can be reduced by increasing the number of sup-


ply wells per desired water—use rate. Minimizing well depth is probably
 

the single most effective step in controlling intrusion.
 

75
 
SELECTED REFERENCES--Continued
 

Bouwer, Herman, 1978, Groundwater hydrology:New York, McGraw—Hill, 480 p.
 

Bush, P. W., 1978, Hydrologic evaluation of part of central Volusia County,
 

Florida: U.S. Geological Survey Open—File Report 78—89, 50 p.
 

Cooke, C. W., 1945, Geology of Florida: Florida Geological Survey Bulletin 29, 342 p.
 

Grubb, H. F., and Rutledge, A. T., 1979, Long—term water supply potential, Green
 

Swamp area, Florida: U.S. Geological Survey Water—Resources Investigations 78—
 

99, 76 p.
 

Hubbert, M. K., 194O, The theory of ground—water motion: Journal of Geology, v. 48, 
 

p. 785—944.
 

Knochenmus, D. D., 1968, Surface drainage characteristics in Volusia County,
 

Florida: Florida Bureau of Geology Map Series 30, 1 sheet.
 

Knocheninus, D. D., and Beard, M. E., 1971, Evaluation of the quantity and quality of 
 

water resources of Volusia County, Florida: Florida Bureau of Geology Report of 
 

Investigations 57, 59 p.
 

Lichtler, W. F., Anderson, Warren, and Joyner, B. F., 1968, Water resources of Orange 
 

County, Florida: Florida Bureau of Geology Report of Investigations 50, 150 p.
 

Lohman, S. W., 1979, Ground—water hydraulics: U.S. Geological Survey Professional 
 

Paper 708, 70 p.
 

Lohman, S. W., and others, 1972, Definition of selected ground—water terms——revisions 
 

and conceptual refinements: U.S. Geological Survey Water—Supply Paper 1988, 21 
 

p.
 

Marella, Richard, 1982, Annual water use survey: 1980: St. Johns River Water Manage­


ment District Technical Report no. 14, 166 p.
 

Miller, 3. A., 1981, Thickness of the upper permeable zone of the tertiary limestone 
 

aquifer system, southeastern United States: U.S. Geological Survey Water—
 

Resources Investigations Open—File Report 81—1179, 1 sheet.
 

-----, 1984, Geohydrologic framework of the Floridan aquifer system in Florida and in 
 

parts of Georgia, South Carolina, and Alabama: U.S. Geological Survey Profes­


sional Paper ---- (in press).
 

Rutledge, A. T., 1982, Hydrology of the Floridan aquifer in northwest Volusia County, 
 

Florida: U.S. Geological Survey Open—File Report 82—108, 116 p.
 

76
 
SELECTED REGERENCES--Continued
 

Schiner, G. R., and Hayes, E. C., 1982, Potentiometric surface of the Floridan aqui­


fer in the St. Johns River Water Management District and vicinity, Florida, Sep­


tember 1982: U.S. Geological Survey Open—File Report 83—30, 1 sheet.
 

Simonds, E. P., Jr., McPherson, B. F., and Bush, P. W., 1980, Shallow groundwater 
 

conditions and vegetation classification, central Volusia County,
 

Florida: U.S. Geological Survey Open—File Report 80—752, 1 sheet.
 

U.S. Soil Conservation Service, 1980, Soil survey of Volusia County, Florida:
 

207 p.
 

Wyrick, G. G., 1960, The ground—water resources of Volusia County, Florida:
 

Florida Geological Survey Report of Investigations 22, 65 p.
 

1961, Record of wells in Volusia County, Florida: Florida Geological Survey Informa­


tion Circular 24, 96 p.
 

77
 
TABLE OF SUPPLEMENTAL DATA--CHLORIDE CONCENTRATIONS IN PUBLIC-SUPPLY WELLS. 

DATE OF CHLORIDE 

SAMPLING TIME OF CONCENTRATI 

STATION NO. LOCAL NO. AND WELL NAME (YR—MO—D) SAMPLING ON (MG/L) 

291423081011901 91410101 OLD P.S. WELL, SEABREEZE #1, DAYTONA 54—03—02 —— 146 

291423081011902 91410102 OLD P.S. WELL, SEABREEZE #2, DAYTONA 54—03—02 —— 130 

291422081012101 91410103 OLD P.S. WELL, SEABREEZE #3, DAYTONA 54--03—02 —— 96 

291423081012201 91410104 OLD P.S. WELL, SEABREEZE #4, DAYTONA 54—11—02 —— 116 

291421081012301 91410105 OLD P.S. WELL, SEABREEZE #5, DAYTONA 54—03—02 —— 188 

291421081012202 91410106 OLD P.S. WELL, SEABREEZE #6, DAYTONA 54—03—02 —— 630 

291421081012202 91410107 OLD P.S. WELL, SEABREEZE #7, DAYTONA 54—03—02 —— 682 

291421081012202 91410107 OLD P.S. WELL, SEABREEZE #7, DAYTONA 81—05—04 1250 130 

291421081012202 91410107 OLD P.S. WELL, SEABREEZE #7, DAYTONA 81—07—14 1115 120 

291204081020501 91210201 DAYTONA P.S. WELL #1, ORANGE AV, DAYTONA 37—07—11 —— 1645 

291204081020501 91210201 DAYTONA P.S. WELL #1, ORANGE AV, DAYTONA 37—07—16 —— 1585 

291204081020501 91210201 DAYTONA P.S. WELL #1, ORANGE AV, DAYTONA 37—07—24 —— 355 

291204081020501 91210201 DAYTONA P.S. WELL #1, ORANGE AV, DAYTONA 37—37—27 —— 1160 

291204081020501 91210201 DAYTONA P.S. WELL #1, ORANGE AV, DAYTONA 37—07—29 —— 1085 

291204081020501 91210201 DAYTONA P.S. WELL #1, ORANGE AV, DAYTONA 37—08—02 ----- 890 

291158081015801 91210202 DAYTONA P.S. WELL #2, MALEY, DAYTONA 39—00—00 —— 100 

291158081015801 91210202 DAYTONA P.S. WELL #2, MALEY, DAYTONA 50—00—00 —— 96 

291158081015801 91210202 DAYTONA P.S. WELL #2, MALEY, DAYTONA 54—02--25 —— 146 

291158081015801 91210202 DAYTONA P.S. WELL #2, MALEY, DAYTONA 81—04—28 1225 160 

291158081015801 91210202 DAYTONA P.S. WELL #2, MALEY, DAYTONA 81—04—28 1245 160 

291158081015801 91210202 DAYTONA P.S. WELL #2, MALEY, DAYTONA 82—12—08 1415 150 

291159081020201 91210203 DAYTONA P.S. WELL #3, MALEY, DAYTONA 39—00—00 —— 113 

291159081020201 91210203 DAYTONA P.S. WELL #3, MALEY, DAYTONA 50—00—00 —— 134 

291159081020201 91210203 DAYTONA P.S. WELL #3, MALEY, DAYTONA 54—02—28 —- 186 

291159081020201 91210203 DAYTONA P.S. WELL #3, MALEY, DAYTONA 79—09—10 —— 1010 

291159081020201 91210203 DAYTONA P.S. WELL #3, MALEY, DAYTONA 81—04—28 1022 750 

291159081020201 91210203 DAYTONA P.S. WELL #3, MALEY, DAYTONA 81—04—28 1032 1000 

291159081020201 91210203 DAYTONA P.S. WELL #3, MALEY, DAYTONA 81—04—28 1102 1000 

291159081020201 91210203 DAYTONA P.S. WELL #3, MALEY, DAYTONA 82—12—08 1450 300 

291202081020101 91210204 DAYTONA P.S. WELL #4, PALSY, DAYTONA 39—00—00 —— 117 

291202081020101 91210204 DAYTONA P.S. WELL #4, PALSY, DAYTONA 50—00—00 —— 134 

291202081020101 91210204 DAYTONA P.S. WELL #4, PALSY, DAYTONA 54—02—28 —— 182 

291205061020301 91210205 DAYTONA P.S. WELL #5, ADAMS, DAYTONA 39—00—00 —— 119 

291205061020301 91210205 DAYTONA P.S. WELL #5, ADAMS, DAYTONA 50—00—00 —— 134 

291205061020301 91210205 DAYTONA P.S. WELL #5, ADAMS, DAYTONA 54—02—28 —— 160 

291207081020301 91210206 DAYTONA P.S. WELL #6, ADAMS, DAYTONA 39—00—00 —— 102 

291207081020301 91210206 DAYTONA P.S. WELL #6, ADAMS, DAYTONA 50—00—00 —— 122 

291207081020301 91210206 DAYTONA P.S. WELL #6, ADAMS, DAYTONA 54—02—28 —— 146 

291210081020501 91210207 DAYTONA P.S. WELL #7, ADAMS, DAYTONA 39—00—00 —— 99 

291210081020501 91210207 DAYTONA P.S. WELL #7, ADAMS, DAYTONA 50—00—00 —— 127 

291210081020501 91210207 DAYTONA P.S. WELL #7, ADAMS, DAYTONA 54—02—28 —— 132 

291213081020701 91210208 DAYTON P.S. WELL #8, ADAMS, DAYTONA 39--00--00 —— 90 

291213081020701 91210208 DAYTON P.S. WELL #8, ADAMS, DAYTONA 50—00—00 ---- 86 

291213081020701 91210208 DAYTON P.S. WELL #8, ADAMS, DAYTONA 54—02--28 —— 98 

291215081020801 91210209 DAYTONA P.S. WELL #9, ADAMS. DAYTONA 39—00—00 —— 99 

291215081020801 91210209 DAYTONA P.S. WELL #9, ADAMS. DAYTONA 50—00—00 —— 70 

291215081020801 91210209 DAYTONA P.S. WELL #9, ADAMS. DAYTONA 54—02—28 —— 82 

291207081020801 91210211 DAYTONA P.S. WELL #11, KEECH, DAYTONA 50—00--00 —— 198 

291207081020801 91210211 DAYTONA P.S. WELL #11, KEECH, DAYTONA 54—02—25 —— 148 

291210081021001 91210212 DAYTONA P.S. WELL #12, KEECH, DAYTONA 50—00—00 —— 78 

291210081021001 91210212 DAYTONA P.S. WELL #12, KEECH, DAYTONA 54—02—25 —— 86 

291212081021101 91210213 DAYTONA P.S. WELL #13, KEECH, DAYTONA 50—00—00 —— 62 

291212081021101 91210213 DAYTONA P.S. WELL #13, KEECH, DAYTONA 54—02—25 —— 88 

291210081021401 91210214 DAYTONA P.S.WELL #14, CAROLINE, DAYTONA 50—00—00 —— 60 

291210081021401 91210214 DAYTONA P.S.WELL #14, CAROLINE, DAYTONA 56—02—25 —— 94 

78 
TABLE OF SUPPLEMENTAL DATA--CHLORIDE CONCENTRATIONS IN PUBLIC-SUPPLY WELLS. 

CONTINUED 

DATE OF CHLORIDE 

SAMPLING (YR-- TIME OF CONCENTRATI 

STATION NO. LOCAL NO. AND WELL NAME MO—D) SAMPLING ON (MG/L) 

291208081021301 91210215
 

291208081021301 91210215
 

291158081020901 91210216
 

291158081020901 91210216
 

291156081020701 91210217
 

291156081020701 91210217
 

291156081020301 91210218
 

291156081020301 91210218
 

291159081020401 91210219
 

291159081020401 91210219
 

291202081020501 91210220
 

291207081022101 91210221
 

291207081022101 91210221
 

291210081022301 91210222
 

291210081022301 91210222
 

291215081022501 91210223
 

291215081022501 91210223
 

291219081022801 91210224
 

291219081022801 91210224
 

291224081023001 91210225
 

291224081023001 91210225
 

291229081023201 91210226
 

291229081023201 91210226
 

291233081023501 91210227
 

291233081023501 91210227
 

291237081023701 91210228
 

291237081023701 91210228
 

291242081023901 91210229
 

291242081023901 91210229
 

291202081022301 91210235
 

291202081022301 91210235
 

291202081022301 91210235
 

291155081022901 91210237
 

291155081022901 91210237
 

291155081022901 91210237
 

291152081023701 91110203
 

291152081023701 91110203
 

291139081032401 91110305
 

291139081032401 91110305
 

291139081032401 91110305
 

291140081033601 91110306
 

291137081034801 91110303
 

291133081035801 91110302
 

291133081035801 91110302
 

291133081035801 91110302
 

291133081035801 91110302
 

291133081035801 91110302
 

291130011040601 91110407
 

291130011040601 91110407
 

291130011040601 91110407
 

291130011040601 91110407
 

DAYTONA P.S. WELL #15,CAROLINE,DAYTONA 

DAYTONA P.S. WELL #15,CAROLINE,DAYTONA 

DAYTONA P.S. WELL #16.CAROLINE,DAYTONA 

DAYTONA P.S. WELL #16.CAROLINE,DAYTONA 

DAYTONA P.S.WELL #17,CAROLNE,DAYTONA 

DAYTONA P.S.WELL #17,CAROLNE,DAYTONA 

DAYTONA P.S.WELL #18, KEECH,DAYTONA 

DAYTONA P.S.WELL #18, KEECH,DAYTONA 

DAYTONA P.S. WELL #19, KEECH, DAYTONA 

DAYTONA P.S. WELL #19, KEECH, DAYTONA 

DAYTONA P.S. WELL #20, KEECH, DAYTONA 

DAYTONA P.S. WELL #21, NOVA, DAYTONA 

DAYTONA P.S. WELL #21, NOVA, DAYTONA 

DAYTONA P.S. WELL #22, NOVA, DAYTONA 

DAYTONA P.S. WELL #22, NOVA, DAYTONA 

DAYTONA P.S. WELL #23, NOVA. DAYTONA 

DAYTONA P.S. WELL #23, NOVA. DAYTONA 

DAYTONA P.S.WELL #24, NOVA. DAYTONA 

DAYTONA P.S.WELL #24, NOVA. DAYTONA 

DAYTONA P.S. WELL #25, NOVA, DAYTONA 

DAYTONA P.S. WELL #25, NOVA, DAYTONA 

DAYTONA P.S. WELL #26, NOVA, DAYTONA 

DAYTONA P.S. WELL #26, NOVA, DAYTONA 

DAYTONA P.S. WELL #27, NOVA, DAYTONA 

DAYTONA P.S. WELL #27, NOVA, DAYTONA 

DAYTONA P.S. WELL #28, NOVA. DAYTONA 

DAYTONA P.S. WELL #28, NOVA. DAYTONA 

DAYTONA P.S. WELL #29, NOVA, DAYTONA 

DAYTONA P.S. WELL #29, NOVA, DAYTONA 

DAYTONA P.S. WELL #30, TUSC., DAYTONA 

DAYTONA P.S. WELL #30, TUSC., DAYTONA 

DAYTONA P.S. WELL #30, TUSC., DAYTONA 

DAYTONA P.S. WELL #32, TUSC., DAYTONA 

DAYTONA P.S. WELL #32, TUSC., DAYTONA 

DAYTONA P.S. WELL #32, TUSC., DAYTONA 

DAYTONA P.S. WELL. #33, DAYTONA 

DAYTONA P.S. WELL. #33, DAYTONA 

DAYTONA P.S. WELL #34, DAYTONA 

DAYTONA P.S. WELL #34, DAYTONA 

DAYTONA P.S. WELL #34, DAYTONA 

DAYTONA P.S. WELL #35, DAYTONA 

DAYTONA P.S. WELL #36, DAYTONA 

DAYTONA P.S. WELL #37, DAYTONA 

DAYTONA P.S. WELL #37, DAYTONA 

DAYTONA P.S. WELL #37, DAYTONA 

DAYTONA P.S. WELL #37, DAYTONA 

DAYTONA P.S. WELL #37, DAYTONA 

DAYTONA P.S. WELL #33, DAYTONA 

DAYTONA P.S. WELL #33, DAYTONA 

DAYTONA P.S. WELL #33, DAYTONA 

DAYTONA P.S. WELL #33, DAYTONA 

79
 

50—00—00 —— 99 

54—02—25 —— 128 

50—00—00 —— 123 

54—02—25 —— 186 

50—00—00 —— 145 

54—02—00 —— 188 

50—00—00 —— 150 

54—02—00 —— 186 

50—00—00 —— 145 

54--02--00 —— 202 

54—02—00 —— 198 

54—02—28 —— 82 

54—03—31 —— 126 

54—02—28 —— 78 

54—03—31 —— 92 

54—02—23 —— 64 

54—03—31 —— 78 

54—02—28 —— 68 

54—03—31 —— 80 

54—02—00 —— 52 

54—03—31 —— 48 

54—02—00 —— 48 

54—03—31 —— 44 

54—02—00 —— 56 

54—03—31 —— 56 

54—02—00 —— 56 

34—03—31 —— 52 

54—02—00 —— 52 

54—03—31 —— 54 

79—09—00 580 

79—09—06 1325 581 

82—08—24 1200 640 

80--12--31 —— 150 

80—12—31 1115 150 

80—12—31 1121 140 

82—08—24 1120 170 

82—12—01 1545 150 

57—03—00 —— 78 

57—03—13 —— 70 

57—03—21 —— 78 

57—03—13 —— 30 

57—03—13 —— 30 

57—03—00 —— 33 

57—03—13 —— 30 

57—33—21 —— 33 

82—03—20 1135 66 

82—12—01 1325 53 

57—03--13 —— 32 

82—03—22 1500 99 

82—08—20 1130 35 

82--12--01 1312 40 
TABLE OF SUPPLEMENTAL DATA--CHLORIDE CONCENTRATIONS IN PUBLIC-SUPPLY WELLS. 

CONTINUED 

DATE OF CHLORIDE 

SAMPLING (YR- TIME OF CONCENTRATI 

STATION NO. LOCAL NO. AND WELL NAME MO-D) SAMPLING ON (MG/L) 

291126081041701 91110406 

291126081041701 91110406 

291126081041701 91110406 

291120081042701 91110408 

291120081042701 91110408 

291120081042701 91110408 

291126081043401 91110410 

291126081043401 91110410 

291126081043401 91110410 

291120081044501 91110412 

291120081044501 91110412 

291116081045501 91110413 

291116081045501 91110413 

291116081045501 91110413 

291116081045501 91110413 

291113081050601 91110503 

291113081050601 91110503 

291113081050601 91110503 

291113081050601 91110503 

291113081050601 91110503 

291113081050601 91110503 

291113081050601 91110503 

291109081051601 91110501 

291109081051601 91110501 

291109081051601 91110501 

291105081052301 91110504 

291105081052301 91110504 

291105081052301 91110504 

291105081052301 91110504 

291101081053601 91110505 

291101081053601 91110505 

291047081061301 91010602 

291047081061301 91010602 

291032081065201 91010601 

291032081065201 91010601 

291032081065201 91010601 

291032081065201 91010601 

291032081065201 91010601 

291031081065601 91010603 

291043081071201 91010701 

290830381074401 90810705 

290823081080401 90810807 

290820081081401 90810808 

290812081083201 90810810 

290139081182401 90111701 

290139081182401 90111701 

290139081182401 90111701 

290156081183501 90111801 

290156081183501 90111801 

290156081183501 90111801 

290156081183501 90111801 

290156081183501 90111801 

DAYTONA P.S. WELL #39, DAYTONA 

DAYTONA P.S. WELL #39, DAYTONA 

DAYTONA P.S. WELL #39, DAYTONA 

DAYTONA P.S. WELL #40, DAYTONA 

DAYTONA P.S. WELL #40, DAYTONA 

DAYTONA P.S. WELL #40, DAYTONA 

DAYTONA P.S. WELL #41, DAYTONA 

DAYTONA P.S. WELL #41, DAYTONA 

DAYTONA P.S. WELL #41, DAYTONA 

DAYTONA P.S. WELL #42, DAYTONA 

DAYTONA P.S. WELL #42, DAYTONA 

DAYTONA P.S. WELL #43, DAYTONA 

DAYTONA P.S. WELL #43, DAYTONA 

DAYTONA P.S. WELL #43, DAYTONA 

DAYTONA P.S. WELL #43, DAYTONA 

CITY WELL 44 AT DAYTONA BEACH, FL 

CITY WELL 44 AT DAYTONA BEACH, FL 

CITY WELL 44 AT DAYTONA BEACH, FL 

CITY WELL 44 AT DAYTONA BEACH, FL 

CITY WELL 44 AT DAYTONA BEACH, FL 

CITY WELL 44 AT DAYTONA BEACH, FL 

CITY WELL 44 AT DAYTONA BEACH, FL 

DAYTONA P.S. WELL #45, DAYTONA 

DAYTONA P.S. WELL #45, DAYTONA 

DAYTONA P.S. WELL #45, DAYTONA 

DAYTONA P.S. WELL #46, DAYTONA 

DAYTONA P.S. WELL #46, DAYTONA 

DAYTONA P.S. WELL #46, DAYTONA 

DAYTONA P.S. WELL #46, DAYTONA 

DAYTONA P.S. WELL #47, DAYTONA 

DAYTONA P.S. WELL #47, DAYTONA 

DAYTONA P.S. WELL #48, SW OF DAYTONA 

DAYTONA P.S. WELL #48, SW OF DAYTONA 

DAYTONA P.S. WELL #49, SW OF DAYTONA 

DAYTONA P.S. WELL #49, SW OF DAYTONA 

DAYTONA P.S. WELL #49, SW OF DAYTONA 

DAYTONA P.S. WELL #49, SW OF DAYTONA 

DAYTONA P.S. WELL #49, SW OF DAYTONA 

DAYTONA P.S. WELL W—1, W. OF DAYTONA 

DAYTONA P.S. WELL W—2, W.OF DAYTONA 

DAYTONA P.S. WELL W—3,SW. OF DAYTONA 

DAYTONA P.S. WELL W—5. SW OF DAYTONA 

DAYTONA P.S. WELL W—6. SW OF DAYTONA 

DAYTONA P.S. WELL W--8, SW OF DAYTONA 

DELAND P.S. WELL #2, DELAND 

DELAND P.S. WELL #2, DELAND 

DELAND P.S. WELL #2, DELAND 

DELAND P.S. WELL #3, DELAND 

DELAND P.S. WELL #3, DELAND 

DELAND P.S. WELL #3, DELAND 

DELAND P.S. WELL #3, DELAND 

DELAND P.S. WELL #3, DELAND 

80 

57—03—13 —— 32 

82—03—22 1505 71 

82—08—20 1125 71 

57—03—13 —— 30 

82—12--01 1307 55 

83—01—31 1245 48 

63—09—12 —— 34 

82—08—20 1115 55 

82—12—01 1303 42 

82—03—22 1510 42 

82—08--20 1110 40 

66—06—26 —— 63 

82—03—22 1515 61 

82—08—20 1105 63 

82—12—01 1254 69 

66—06—24 —— 74 

69—05—15 1030 39 

71—06—09 —— 41 

72—05—08 1220 38 

82—08—20 1100 130 

82—12—01 1250 110 

83—01—31 1250 72 

66—07—06 —— 55 

82—05—20 1050 210 

82—12—01 1232 160 

72—06—01 —— 35 

79—09—00 —— 47 

82—08—20 1040 230 

82—12—01 1240 42 

72—06—02 —— 30 

52—08—20 1030 33 

82—03—22 1520 33 

82—08—20 945 34 

72—07—14 —— 34 

80—03—00 —— 30 

80—03—11 945 27 

82—03—22 1525 31 

82—08--20 1000 36 

82—12—28 1045 25 

82—12—28 1105 27 

82—12—16 1250 19 

82—12—16 1245 23 

82—12—16 1240 33 

82—12—16 1220 32 

57—04—22 —— 24 

52—08—20 1400 13 

82—11—30 850 20 

57—04—22 —— 19 

66—02—15 —— 19 

82—03—23 1400 35 

82—08—20 1405 33 

82—11—30 840 40 
TABLE OF SUPPLEMENTAL DATA--CHLORIDE CONCENTRATIONS 

IN PUBLIC-SUPPLY WELLS--CONTINUED 

CHLORIDE 

DATE OF TIME OF CONCENTRATI 

STATION NO. LOCAL NO. AND WELL NAME SAMPLING SAMPLING ON (MG/L) 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290156081183401 90111802
 

290219081190601 90211901
 

290227081171301 90211701
 

290227081171301 90211701
 

290227081171301 90211701
 

290227081171301 90211701
 

290227081171301 90211701
 

290227081171301 90211701
 

290227081171301 90211701
 

290227081171301 90211701
 

290227081171301 90211701
 

290227081171301 90211701
 

290208081172401 90211702
 

290113081173201 90111703
 

290113081173201 90111703
 

290113081173201 90111703
 

290308081182301 90311801
 

290308081182301 90311801
 

290156081192701 90111902
 

290156081192701 90111902
 

285419081153901 85411505
 

285419081153901 85411505
 

285419081153901 85411505
 

285419081153901 85411505
 

285416081154401 85411504
 

285416081154401 85411504
 

285416081154401 85411504
 

265359081161701 85311601
 

265359081161701 85311601
 

265359081161701 85311601
 

265359081161701 85311601
 

285525081143301 85511401
 

285525081143301 85511401
 

285525081143301 85511401
 

285525081143301 85511401
 

285525081143301 85511401
 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #4, DELAND 

DELAND P.S. WELL #5, DELAND 

DELAND P.S. WELL #6, DELAND 

DELAND P.S. WELL #6, DELAND 

DELAND P.S. WELL #6, DELAND 

DELAND P.S. WELL #6, DELAND 

DELAND P.S. WELL #6, DELAND 

DELAND P.S. WELL #6, DELAND 

DELAND P.S. WELL #6, DELAND 

DELAND P.S. WELL #6, DELAND 

DELAND P.S. WELL #6, DELAND 

DELAND P.S. WELL #6, DELAND 

DELAND P.S. WELL #6A, DELAND 

DELAND P.S. WELL #7, DELAND 

DELAND P.S. WELL #7, DELAND 

DELAND P.S. WELL #7, DELAND 

DELAND P.S. WELL #7A, DELAND 

DELAND P.S. WELL #7A, DELAND 

DELAND P.S. WELL #8, DELAND 

DELAND P.S. WELL #8, DELAND 

DELT. P.S. WELL #1, WELLINGTON. DELTONA 

DELT. P.S. WELL #1, WELLINGTON. DELTONA 

DELT. P.S. WELL #1, WELLINGTON. DELTONA 

DELT. P.S. WELL #1, WELLINGTON. DELTONA 

DELT. P.S. WELL #2, WELLINGTON, DELTONA 

DELT. P.S. WELL #2, WELLINGTON, DELTONA 

DELT. P.S. WELL #2, WELLINGTON, DELTONA 

DELT. P.S. WELL #3, DIAMOND ST. DELTONA 

DELT. P.S. WELL #3, DIAMOND ST. DELTONA 

DELT. P.S. WELL #3, DIAMOND ST. DELTONA 

DELT. P.S. WELL #3, DIAMOND ST. DELTONA 

DELT. P.S. WELL #4, ELKCAM BLVD, DELTONA 

DELT. P.S. WELL #4, ELKCAM BLVD, DELTONA 

DELT. P.S. WELL #4, ELKCAM BLVD, DELTONA 

DELT. P.S. WELL #4, ELKCAM BLVD, DELTONA 

DELT. P.S. WELL #4, ELKCAM BLVD, DELTONA 

81
 

57--04--22 —— 21 

58—07—15 —— 17 

66—02—00 —— 19 

66--02--15 —— 19 

71—06—08 —— 26 

76—08—17 0820 19 

77—09—01 1515 18 

80--03--11 3800 46 

82—08—20 1410 20 

82—11—30 0835 28 

83—02—01 1240 28 

83—03—31 1250 25 

83—04--29 1015 25 

83—05—27 1230 27 

83--06--30 1135 26 

83—09—30 1200 28 

83—11—29 0930 30 

84—01--31 0920 29 

84—04—05 1245 28 

84—05—04 0940 33 

86—06—07 0930 27 

84—07—06 1200 33 

82—08—20 1415 12 

65—09—00 —— 15 

65—09—02 —— 15 

65--10--28 1620 12 

65—11—00 —— 12 

65—11—01 —— 12 

65—12—00 1440 10 

65—12—00 1540 8 

65—12—02 —— 10 

65—12—02 1440 10 

65—12—02 1540 8 

82—08—20 1420 11 

57—04—22 —— 24 

58—07—15 —— 18 

61—05—12 —— 18 

82—03—23 1405 14 

82—08—20 1425 13 

82—03—23 1410 16 

82—08--20 1430 12 

67—12—13 —— 10 

82—03--29 1000 23 

82—08--24 0800 16 

82—12—01 0955 12 

67—10—25 —— 9 

82—03—29 1005 79 

82—08—24 0805 24 

65—07—13 —— 28 

82—03—29 1010 19 

82—08—24 0815 10 

82—12—01 0900 9 

67—10—25 —— 53 

79—09—10 1230 80 

82—03—29 1015 105 

82—08—24 0820 110 

82—12—01 0815 100 
TABLE OF SUPPLEMENTAL DATA--CHLORIDE CONCENTRATIONS 

IN PUBLIC-SUPPLY WELLS--CONTINUED 

DATE OF CHLORIDE 

SAMPLING (YR- TIME OF CONCENTRATI 

STATION NO. LOCAL NO. AND WELL NAME MO-D) SAMPLING ON (MG/L) 

285259081132101 85211301 

285259081132101 85211301 

285406081152301 85411501 

285406081152301 85411501 

285406081152301 85411501 

285406081152301 85411501 

285201081150201 85211504 

285410081152301 85411502 

285410081152301 85411502 

285410081152301 85411502 

285410081152301 85411502 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285348081140801 85311402 

285503081124701 85511201 

285340081140801 85311401 

285340081140801 85311401 

285340081140801 85311401 

285253081141301 85211401 

285253081141301 85211401 

285253081141301 85211401 

285253081141301 85211401 

285253081141301 85211401 

285631081105201 85611001 

285352081141001 85311403 

285352081141001 85311403 

285352081141001 85311403 

285634081105301 85611002 

285904080554601 85905504 

285904080554601 85905504 

285904080554601 85905504 

285904080554601 85905504 

285904080554601 85905504 

285904080554601 85905504 

285904080554601 85905504 

28585808055701 85805501 

28585808055701 85805501 

285852080561401 85805601 

285852080561401 85805601 

291444081022201 91410201 

291444081022201 91410201 

291444081022201 91410201 

291444081022201 91410201 

291444081022201 91410201 

DELT. P.S. WELL #5, SAXON, DELTONA 

DELT. P.S. WELL #5, SAXON, DELTONA 

DELT. P.S. WELL #6, FIRE STA., DELTONA 

DELT. P.S. WELL #6, FIRE STA., DELTONA 

DELT. P.S. WELL #6, FIRE STA., DELTONA 

DELT. P.S. WELL #6, FIRE STA., DELTONA 

DELT. P.S. WELL #7, WHISKEY L., DELTONA 

DELT. P.S. WELL #8, FIRE STA., DELTONA 

DELT. P.S. WELL #8, FIRE STA., DELTONA 

DELT. P.S. WELL #8, FIRE STA., DELTONA 

DELT. P.S. WELL #8, FIRE STA., DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #9, SAXON BLVD, DELTONA 

DELT. P.S. WELL #11, NEMO ST. DELTONA 

DELT. P.S. WELL #12, HOLLYHOCK, DELTONA 

DELT. P.S. WELL #12, HOLLYHOCK, DELTONA 

DELT. P.S. WELL #12, HOLLYHOCK, DELTONA 

DELT. P.S. WELL #14, SAXON BLVD,DELTONA 

DELT. P.S. WELL #14, SAXON BLVD,DELTONA 

DELT. P.S. WELL #14, SAXON BLVD,DELTONA 

DELT. P.S. WELL #14, SAXON BLVD,DELTONA 

DELT. P.S. WELL #14, SAXON BLVD,DELTONA 

DELT. P.S. WELL #15, COURTLAND, DELTONA 

DELT. P.S. WELL #16, DELTONA 

DELT. P.S. WELL #16, DELTONA 

DELT. P.S. WELL #16, DELTONA 

DELT. P.S. WELL #17, COURTLAND, DELTONA 

EDGEWATER P.S. WELL #1, W. OF EDGEWATER 

EDGEWATER P.S. WELL #1, W. OF EDGEWATER 

EDGEWATER P.S. WELL #1, W. OF EDGEWATER 

EDGEWATER P.S. WELL #1, W. OF EDGEWATER 

EDGEWATER P.S. WELL #1, W. OF EDGEWATER 

EDGEWATER P.S. WELL #1, W. OF EDGEWATER 

EDGEWATER P.S. WELL #1, W. OF EDGEWATER 

EDGEWATER P.S. WELL #2, W. OF EDGEWATER 

EDGEWATER P.S. WELL #2, W. OF EDGEWATER 

EDGEWATER P.S. WELL #3, W. OF EDGEWATER 

EDGEWATER P.S. WELL #3, W. OF EDGEWATER 

HOLLY HILL P.S. WELL #1, HOLLY HILL 

HOLLY HILL P.S. WELL #1, HOLLY HILL 

HOLLY HILL P.S. WELL #1, HOLLY HILL 

HOLLY HILL P.S. WELL #1, HOLLY HILL 

HOLLY HILL P.S. WELL #1, HOLLY HILL 

82 

65--11--15 —— 38 

82—04—13 1100 99 

66—03—14 —— 39 

82—04—13 1105 22 

82—08—24 825 18 

82—12—01 845 15 

67—10—25 —— 9 

67—01—03 —— 9 

82—04—13 1110 49 

82—08—24 830 12 

82—12—01 947 14 

66—12—13 —— 15 

77—11—02 1330 140 

82—03—29 1025 240 

82—08—24 835 120 

82—12—01 833 78 

83—02—01 1320 60 

53—03—31 1400 89 

83—04—29 930 97 

83—05—27 1145 64 

83—06—30 1215 58 

83—09—30 1300 56 

83—12—02 840 66 

84—01—31 1030 73 

84—04—05 1410 51 

84—05—06 1045 64 

84—06—07 1050 66 

68—12—16 —— 360 

82—04—13 1115 67 

82—08—24 840 70 

82—12—01 830 70 

70—12—07 —— 60 

79—09—10 1140 114 

82—03—29 1030 170 

82—08—26 840 42 

82—12—01 836 24 

82—03—29 1035 30 

82—03--29 1040 240 

82—08—24 845 130 

82—12—01 835 91 

82--03--29 1045 9 

57--12--00 —— 64 

58--06--10 —— 45 

72--05--10 1500 78 

76--08--27 945 58 

79--09--00 —— 110 

82--03--22 1145 210 

82--12--08 1240 210 

82--03--22 1150 160 

82--12--08 1250 140 

82--03--22 1155 58 

82--12--08 1245 55 

50--04--05 —— 70 

50--08--00 —— 73 

50--09--00 —— 75 

54--11--16 —— 71 

77--11--02 1515 160 
TABLE OF SUPPLEMENTAL DATA--CHLORIDE CONCENTRATIONS 

IN PUBLIC-SUPPLY WELLS--CONTINUED 

DATE OF CHLORIDE 

SAMPLING (YR- TIME OF CONCENTRATI 

STATION NO. LOCAL NO. AND WELL NAME MO-D) SAMPLING ON (MG/L) 

291434081025002 91410211 

291429081024702 91410213 

291429081024702 91410213 

291429081024702 91410213 

291425081024501 91410214 

291425081024502 91410215 

291436081024701 91410216 

291436081024701 91410216 

291436081024701 91410216 

291436081024701 91410216 

291435081025501 91410218 

290039081204701 90012022 

290039081204701 90012022 

290039081204701 90012022 

290039081204601 90012021 

290039081204601 90012021 

290039081204601 90012021 

285840081135601 85811301 

285840081135601 85811301 

285840081135601 85811301 

285951080574701 85905705 

285951080574701 85905705 

285951080574701 85905705 

285951080574701 85905705 

285951080574701 85905705 

285952080574801 85905701 

285952080574801 85905701 

285951080575101 85905702 

285951080575101 85905702 

285949080575001 85905703 

285949080575001 85905703 

285949080575001 85905703 

285951080575501 85905712 

285953080575902 85905710 

285953080575902 85905710 

285945080580001 85905801 

290040081050101 90010501 

290047081052301 90010503 

285641081175501 85611703 

285641081175501 85611703 

285641081175502 85611704 

285636081175501 85611702 

285636081175501 85611702 

285638081175501 86511705 

291645081034801 91610301 

291645081034801 91610301 

291645081034801 91610301 

291644081034701 91610302 

291644081034701 91610302 

291644081034701 91610302 

HOLLY HILL P.S. WELL #6A, HOLLY HILL 

HOLLY HILL P.S. WELL #7A, HOLLY HILL 

HOLLY HILL P.S. WELL #7A, HOLLY HILL 

HOLLY HILL P.S. WELL #7A, HOLLY HILL 

HOLLY HILL P.S. WELL #8, HOLLY HILL 

HOLLY HILL P.S. WELL #8A, HOLLY HILL 

HOLLY HILL P.S. WELL #9. HOLLY HILL 

HOLLY HILL P.S. WELL #9. HOLLY HILL 

HOLLY HILL P.S. WELL #9. HOLLY HILL 

HOLLY HILL P.S. WELL #9. HOLLY HILL 

HOLLY HILL P.S. WELL #11, HOLLY HILL 

L.BERESFORD P.S. WELL #1, SW OF DELAND 

L.BERESFORD P.S. WELL #1, SW OF DELAND 

L.BERESFORD P.S. WELL #1, SW OF DELAND 

L.BERESFORD P.S. WELL #2, SW OF DELAND 

L.BERESFORD P.S. WELL #2, SW OF DELAND 

L.BERESFORD P.S. WELL #2, SW OF DELAND 

L. HELEN P.S. WELL, LAKE HELEN 

L. HELEN P.S. WELL, LAKE HELEN 

L. HELEN P.S. WELL, LAKE HELEN 

NSB PS WELL NUMBERED 3 IN 1947,N.SMYRNA 

NSB PS WELL NUMBERED 3 IN 1947,N.SMYRNA 

NSB PS WELL NUMBERED 3 IN 1947,N.SMYRNA 

NSB PS WELL NUMBERED 3 IN 1947,N.SMYRNA 

NSB PS WELL NUMBERED 3 IN 1947,N.SMYRNA 

NSB PS WELL NUMBERED 1 IN 1980,N.SMYRNA 

NSB PS WELL NUMBERED 1 IN 1980,N.SMYRNA 

NSB PS WELL NUMBERED 2 IN 1980,N.SMYRNA 

NSB PS WELL NUMBERED 2 IN 1980,N.SMYRNA 

NSB PS WELL NUMBERED 3 IN 1980,N.SMYRNA 

NSB PS WELL NUMBERED 3 IN 1980,N.SMYRNA 

NSB PS WELL NUMBERED 3 IN 1980,N.SMYRNA 

NSB PS WELL NUMBERED 6 IN 1980,N.SMYRNA 

NSB PS WELL NUMBERED 7 IN 1980,N.SMYRNA 

NSB PS WELL NUMBERED 7 IN 1980,N.SMYRNA 

NSB PS WELL NUMBERED 8 IN 1980,N.SMYRNA 

NSB P.S. WELL #53, SAMSULA 

NSB P.S. WELL #55, SAMSULA 

ORAN.CITY P.S. WELL #1, ORANGE CITY 

ORAN.CITY P.S. WELL #1, ORANGE CITY 

ORAN.CITY P.S. WELL #2, ORANGE CITY 

ORAN.CITY P.S. WELL #3, ORANGE CITY 

ORAN.CITY P.S. WELL #3, ORANGE CITY 

ORAN.CITY P.S. WELL #4, ORANGE CITY 

ORMOND P.S. WELL #1, ORMOND BEACH 

ORMOND P.S. WELL #1, ORMOND BEACH 

ORMOND P.S. WELL #1, ORMOND BEACH 

ORMOND P.S. WELL #2, ORMOND BEACH 

ORMOND P.S. WELL #2, ORMOND BEACH 

ORMOND P.S. WELL #2, ORMOND BEACH 

83 

82—12—01 1013 70 

82—03—22 1630 190 

82—12—01 958 150 

83—01—31 1330 240 

80—09—23 1530 440 

82—12—01 1030 140 

79—09—00 —— 74 

82—03—22 1635 210 

82—12—31 955 320 

83—01—31 1315 340 

82—12—01 1000 70 

65—08—18 —— 68 

82—08—24 1305 170 

82—12—08 1545 230 

65—08-18 —— 25 

82—05—24 1310 24 

82—12—08 1550 51 

50—11—21 —— 10 

66—04—28 —— 10 

82—12—08 1015 11 

70—05—07 —— 73 

71—05—14 —— 56 

71—06—08 —— 53 

72—05—10 1400 80 

82—12—08 1225 88 

82—12—01 1150 100 

83—01—31 1045 98 

79—09--00 —— 82 

82—03—22 1105 94 

55—06—02 —— 54 

82—12—01 1200 61 

83—01—31 1040 55 

79—09—00 —— 71 

77—12—05 1130 76 

78--05--00 —— 71 

82—03—22 1100 51 

82—03—22 1050 13 

82—03—22 1040 9 

64—08—26 —— 20 

65--08--19 —— 14 

81--12--18 915 18 

65—01—19 —— 11 

68—08—24 —— 16 

82—03—23 1420 19 

54—11—16 —— 200 

82—08—20 1215 230 

82—12—01 1101 230 

54—11—16 —— 220 

82—08—20 1220 180 

82—12—01 1101 120 
TABLE OF SUPPLEMENTAL DATA--CHLORIDE CONCENTRATIONS 

IN PUBLIC-SUPPLY WELLS--CONTINUED 

DATE OF CHLORIDE 

STATION SAMPLING (YR- TIME OF CONCENTRATI 

NO. LOCAL NO. AND WELL NAME MO-D) SAMPLING ON (MG/L) 

291643081034601 91610303 

291643081034601 91610303 

291643081034601 91610303 

291643081034401 91610304 

291641081034501 91610307 

291646081034601 91610306 

291646081034601 91610306 

291646081034601 91610306 

291646081034601 91610306 

291616081040301 91610404 

291616081040301 91610404 

291616081040301 91610404 

291614081040901 91610406 

291607081042301 91610408 

291607081042301 91610408 

291607081042301 91610408 

291608081042101 91610409 

291608081042101 91610409 

291558081044301 91510401 

291628081040101 91610413 

291628081040101 91610413 

291628081040101 91610413 

291623081041101 91610614 

291611081043201 91610416 

291601081060801 91610603 

291527081064601 91510605 

290742081013901 90810103 

290742081013901 90810103 

290742081013901 90810103 

290742081013901 90810103 

290742081013901 90810103 

290742081013901 90810103 

290742081013901 90810103 

290742081013901 90810103 

290813081013801 90810104 

290818081013801 90810105 

290813081014101 90810106 

290813081014101 90810106 

290835081013801 90810108 

290840081013801 90810109 

290846081014401 90810111 

290846081014901 90810112 

290846011015501 90810113 

290846081020101 90810202 

290846081020701 90810203 

ORMOND P.S. WELL #3, ORMOND BEACH 

ORMOND P.S. WELL #3, ORMOND BEACH 

ORMOND P.S. WELL #3, ORMOND BEACH 

ORMOND P.S. WELL #4, ORMOND BEACH 

ORMOND P.S. WELL #5, ORMOND BEACH 

ORMOND P.S. WELL #6, ORMOND BEACH 

ORMOND P.S. WELL #6, ORMOND BEACH 

ORMOND P.S. WELL #6, ORMOND BEACH 

ORMOND P.S. WELL #6, ORMOND BEACH 

ORMOND P.S. WELL #8, ORMOND BEACH 

ORMOND P.S. WELL #8, ORMOND BEACH 

ORMOND P.S. WELL #8, ORMOND BEACH 

ORMOND P.S. WELL #10, ORMOND BEACH 

ORMOND P.S. WELL #12, ORMOND BEACH 

ORMOND P.S. WELL #12, ORMOND BEACH 

ORMOND P.S. WELL #12, ORMOND BEACH 

ORMOND P.S. WELL #13, ORMOND BEACH 

ORMOND P.S. WELL #13, ORMOND BEACH 

ORMOND P.S. WELL #17, ORMOND BEACH 

ORMOND P.S. WELL #18, ORMOND BEACH 

ORMOND P.S. WELL #18, ORMOND BEACH 

ORMOND P.S. WELL #18, ORMOND BEACH 

ORMOND P.S. WELL #19, ORMOND BEACH 

ORMOND P.S. WELL #21, ORMOND BEACH 

ORMOND P.S. WELL #22, ORMOND BEACH 

ORMOND P.S. WELL #24, ORMOND BEACH 

PORT ORANGE P.S. WELL #4, PORT ORANGE 

PORT ORANGE P.S. WELL #4, PORT ORANGE 

PORT ORANGE P.S. WELL #4, PORT ORANGE 

PORT ORANGE P.S. WELL #4, PORT ORANGE 

PORT ORANGE P.S. WELL #4, PORT ORANGE 

PORT ORANGE P.S. WELL #4, PORT ORANGE 

PORT ORANGE P.S. WELL #4, PORT ORANGE 

PORT ORANGE P.S. WELL #4, PORT ORANGE 

PORT ORANGE P.S. WELL #5, PORT ORANGE 

PORT ORANGE P.S. WELL #6, PORT ORANGE 

PORT ORANGE P.S. WELL #7, PORT ORANGE 

PORT ORANGE P.S. WELL #7, PORT ORANGE 

PORT ORANGE P.S. WELL #9, PORT ORANGE 

PORT ORANGE P.S. WELL #10, PORT ORANGE 

PORT ORANGE P.S. WELL #12, PORT ORANGE 

PORT ORANGE P.S. WELL #13, PORT ORANGE 

PORT ORANGE P.S. WELL #14, PORT ORANGE 

PORT ORANGE P.S. WELL #15, PORT ORANGE 

PORT ORANGE P.S. WELL #16, PORT ORANGE 

84 

54—11—16 —— 190 

82—08—20 1225 240 

82—12--01 1103 130 

54--11--16 —— 200 

82--12--01 1105 130 

23—07—00 —— 146 

23—07—08 —— 146 

54—11—16 —— 196 

71—06—08 —— 192 

82—03—23 1200 150 

82—12—01 1129 110 

83—01—31 1410 170 

82—03—23 1205 140 

72—05—05 1100 136 

79—09—00 130 

82--12--01 1121 120 

79--09--00 —— 110 

82—03—23 1210 120 

82—03—23 1215 130 

82—03—23 1220 190 

82—12—01 1113 190 

83—01—31 1400 200 

82—03—23 1225 170 

82—03---23 1230 130 

82—03—23 1235 120 

82—03—23 1240 72 

72—05—10 1300 89 

76—08—27 820 68 

78—04—10 —— 93 

79—08—16 —— 68 

79—09—07 1145 76 

80—03—25 —— 78 

80—10—08 —— 85 

82—03—22 1300 83 

82—03—22 1305 85 

82—03—22 1310 58 

82--12--01 1100 160 

83--01--31 1130 150 

82—03—22 1315 59 

82—03—22 1320 66 

82—03—22 1325 72 

82—03—22 1330 84 

82—03—22 1335 63 

82—03—22 1340 63 

82—03—22 1345 61