EPA/520-6-77-010
EFFECTS OF PHOSPHATE MINERALIZATION
  AND THE PHOSPHATE INDUSTRY ON
    RADIUM-226 IN GROUND WATER
         OF CENTRAL FLORIDA
                    ^
322
                     LU
                     CD
  U.S. ENVIRONMENTAL PROTECTION AGENCY
     OFFICE OF RADIATION PROGRAMS
          LAS VEGAS FACILITY
        LAS VEGAS, NEVADA  89114
             OCTOBER 1977

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                                              EPA/52Q-6-77-Q10
    EFFECTS OF PHOSPHATE MINERALIZATION AND

           THE PHOSPHATE INDUSTRY ON

  RADIUM-226 IN GROUND WATER OF CENTRAL FLORIDA
               Robert F. Kaufmann

                 James D. Bliss
                  October 1977
OFFICE OF RADIATION PROGRAMS - LAS VEGAS FACILITY
      U. S. ENVIRONMENTAL PROTECTION AGENCY
            LAS VEGAS, NEVADA  89114

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                                 DISCLAIMER


     This report has been reviewed by the Office of Radiation Programs--
Las Vegas Facility, U.S. Environmental  Protection Agency, and approved for
publication.  Mention of trade names or commercial products does not constitute
endorsement or recommendation for their use.

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                                   PREFACE

     The Office of Radiation Programs of the U.S. Environmental Protection
Agency carries out a national program designed to evaluate population exposure
to ionizing and non-ionizing radiation and to promote development of controls
necessary to protect the public health and safety.  In-depth field studies of
various radiation sources (e.g. nuclear facilities, uranium mill tailings, and
phosphate mills) provide technical data for environmental impact statement
reviews as well as needed information on source characteristics, environmental
transport, critical pathways for population exposure, and dose model validation

     Where possible in terms of programmatic priorities and available staff,
the Office of Radiation Programs laboratories also provide technical assis-
tance to EPA regional offices.  In this technical assistance role, staff of
the Las Vegas Facility were responsible for assessing the impacts of the
central Florida phosphate industry on radiochemical quality of ground water.
Available geologic, hydrologic, and water quality data were assembled and
interpreted to determine what adverse impacts, if any, are attributable to the
industry and to compare radiochemical quality of ground water in the study
area to State and national conditions.  Finally, recommendations were developed
to mitigate adverse or objectionable situations in terms of preserving environ-
mental quality and public health.

     The reader should be aware that two rather diverse viewpoints surround
this study and report.  Some have considered the data base too limited to
conclude that no widespread or significant contamination has occurred or is
occurring.  Therefore, extensive additional studies are essential.  Others,
particularly industry, consider the data and interpretation herein as con-
firmation that contamination has not occurred, that present practices and data
collection requirements are adequate, and that more study and monitoring would
be inefficient.  The authors explicitly recognize this schism in that while
                                        n i

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the available data are analyzed and conclusions drawn,  criticism as to adequacy

and improvements are also clearly stated.


     Readers of this report are encouraged to inform the Office of Radiation

Programs of any omissions or errors.   Comments or requests for further infor-

mation are also invited.
                                        W.  D.  Rowe,  Ph.D.
                                 Deputy  Assistant  Administrator
                                  Office of Radiation  Programs
                                    IV

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                                  CONTENTS


                                                                         Page

PREFACE                                                                   iii

LIST OF FIGURES                                                           vii

LIST OF TABLES                                                            viii

ACKNOWLEDGMENTS                                                            ix

ABSTRACT                                                                    1

SUMMARY AND CONCLUSIONS                                                     3

RECOMMENDATIONS                                                             7

  Improved Waste Disposal                                                   7
  Monitoring                                                                ?
  Water Sampling and Analysis                                               8
  Hydrology and Geology                                                     9
  Data Interpretation and Reportinp                                        10

PROBLEM DESCRIPTION                                                        11

PREVIOUS AND ONGOING INVESTIGATIONS                                        13

HYDROGEOLOGIC SETTING OF WEST CENTRAL FLORIDA                              15

  Geology of Central Florida                                               15
  Aquifer Systems and Ground-Water Flow                                    20
  Influence of Mining and Processing                                       23

SOURCE TERM CHARACTERIZATION                                               29

SOURCES OF RADIOCHEMICAL DATA                                              34

TECHNIQUES FOR MONITORING RADIUM IN GROUND WATER                           39

  Monitoring Objectives                                                    39
  Sampling Points and Methods for Sampling Radium-226 in Ground Water      39
  Sample Preservation and Handling                                         40
  Significance Relative to Future Studies                                  42

RADIUM IN SURFACE AND GROUND WATER                                         44

  Concentrations in Continental  and Oceanic Waters                         44
  Florida Ground Water                                                     46

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                                 CONTENTS  (Continued)
                                                                          Pa^e
WATER QUALITY EFFECTS OF PHOSPHATE MINERALIZATION AND THE PHOSPHATE        50
  INDUSTRY

  Statistical Methodology                                                  50
  Spatial Variations in Water Quality                                      52

     Water Table Aquifer                                                   52
     Upper Floridan Aquifer                                                55
     Lower Floridan Aquifer                                                56

SARASOTA COUNTY                                                            62

TEMPORAL CHANGES IN WATER QUALITY                                          71

LOCAL CONTAMINATION                                                        73

ADEQUACY OF  INDUSTRY RESPONSE TO THE DRI PROCESS                           82

REFERENCES                                                                 84

APPENDICES

1.  Dissolved radium-226 (pCi/1) in ground water in the central
    Florida phosphate district                                             90

2.  Analytical results from the 1966 FWPCA survey of radium-226
    in central Florida ground water                                        98

3.  Well numbering system                                                 113

4.  Dissolved radium-226 concentration (pCi/1) in ground water in
    Sarasota County                                                       114
                                 VI

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                               LIST OF FIGURES

Number                                                                   Page

  1   General location map                                                 12

  2  Generalized geologic cross section through southern Polk and         17
     northern Hardee Counties

  3  Generalized geologic cross section through northeastern Manatee      18
     County

  4  Generalized southwest-northeast hydrogeologic cross section through  21
     Polk and Manatee Counties

  5  Interaction of mining operations and the hydrogeologic system        24

  6  Location of wells sampled in Polk, Hillsborough, and Hardee Counties 37

  7  Location of wells sampled in Manatee County                          38

  8  Location of counties used to establish background levels of          47
     radium-226 in Florida ground water

  9  Log-probability plot of background levels of radium-226 in           48
     Florida ground water

 10  Log-probability plot of USGS data for the water table aquifer        54
     in unmined and mined mineralized areas

 11  Log-probability plot of USEPA data for the Lower Floridan aquifer    57
     in mined and unmined mineralized areas and in nonmineralized areas

 12  Component populations of radium-226 in the Lower Floridan aquifer    59
     of central Florida

 13  Location of wells sampled for radium-226 in Sarasota County          63

 14  Log-probability plot of radium-226 in the water table and Floridan   64
     aquifers, Sarasota County

 15  Location of radium-226 observations in the water table aquifer in    66
     Sarasota County

 16  Contour map of radium-226 in the Floridan aquifer in Sarasota County 67

 17  Plot of dissolved solids versus radium-226 in Sarasota County        70
     ground water

 18  Gross alpha radioactivity in ground water in the vicinity of         76
     C.F.  Industries, Inc. gypsum ponds

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                               LIST OF TABLES


Number                                                                   Page

  1   Geologic and hydrogeo"logic units in central Florida                   16

  2  Summary of principal  sources of radium-226 data                       35

  3  Summary of the occurrence of dissolved radium in water                45

  4  Summary of available radium-226 data and statistics                   53

  5  Comparison of 1966 and 1974-1976 radium-226 data for the              72
     mineralized area in Polk, Hardee, Manatee, and Hillsborough
     counties
  6  Ground-water quality data from monitoring wells in the                78
     vicinity of the C.F.  Industries, Inc.  gypsum pond near
     Mulberry

  7  Summary of 1973-1976 radium-226 data exceeding 5 pCi/1                80
                                    vm

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                               ACKNOWLEDGMENTS
     Particular appreciation is extended to the many reviewers for their
numerous criticisms and suggestions on the draft report.  Noteworthy in this
regard are staff of the Office of Radiation ProgramsLas Vegas Facility and
the Eastern Environmental Radiation Facility, members of the Florida Phosphate
Council, and especially the chief consultant, Mr. Gordon F. Palm.  Thanks are
also extended to Mr. Gene McNeil 1, EPA, Region IV, for his continuing interest
and patience shown in the many months of report preparation.  Technical advice
and suggestions were freely given by Barbara Boatwright, Southwest Florida
Water Management District, and by William Wilson, Craig Hutchinson, and James
Cathcart of the U.S. Geological Survey.  Mr. Charles R. Russell, formerly with
the Office of Radiation Programs, greatly assisted in the early stages of data
collection and reduction.  A special note of thanks is extended to Mrs.
Edith Boyd and Mr. David Ball for their assistance with typing and drafting.

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      EFFECTS OF PHOSPHATE MINERALIZATION AND THE PHOSPHATE INDUSTRY ON
                RADIUM-226 IN GROUND WATER OF CENTRAL FLORIDA

                                  ABSTRACT

     Principal U. S. phosphate production is from central Florida where
mining, processing, and waste disposal practices intimately associate the
industry with water resources.  Available radium-226 data from 1966 and from
1973-1976 were statistically analyzed to characterize radium in the water
table, Upper Floridan, and Lower Floridan aquifers.  Mined and unmined mineral-
ized areas and nonmineralized areas in the primary study area in Polk, Hardee,
Hi 11sborough, Manatee, and De Soto counties were studied.  Log-normal probabil-
ity plots and nonparametric statistical tests (Mann-Whitney, Kruskal-Wallis,
Kolmogorov-Smirnov, simultaneous multiple comparison) were used to analyze for
central tendency, variance, and significant difference as functions of time,
depth, and location.

     Geometric mean radium-226 content of the water table aquifer in mineral-
ized unmined areas  is 0.17 pCi/1, with few observations exceeding 5 pCi/1.
Compliance with the EPA drinking water standard for dissolved radium (5 pCi/1
for radium-226 plus -228) is likely although confirmatory radium-228 data are
needed.  This is particularly so in areas containing monazite sands where
thorium-232, the parent for radium-228, is elevated relative to other areas of
central Florida.  No significant difference exists in the radium content of
the water table aquifer in mineralized (mined and unmined) areas versus
nonmineralized areas, inferring that mining and mineralization have not caused
a widespread and significant increase in the radium content of this aquifer.

     Radium content of the Upper Floridan aquifer is poorly documented.  For
mineralized but unmined areas, 1 of 5 observations exceeds 5 pCi/1, compared
to 1  of 10 in mined areas.  Simultaneous multiple comparison at the 80
percent confidence level  reveals significant difference between mined and
nonmineralized groups, yet mean radium in nonmineralized areas exceeds that in
                                         1

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mined areas, implying no adverse marked change in radium-226 in the Upper
Floridan aquifer as a result of mining and waste management.  Log-normal
probability plots of radium in the Lower Floridan aquifer for mineralized and
nonmineralized areas are very similar, again indicating that phosphate mineral-
ization or the industry is probably not a factor.  Three separate populations
are indicated with geometric means of 0.7, 3, and 10 pCi/1.

     Radium in the Floridan aquifer in Manatee and Sarasota Counties is
elevated relative to that in the water table and in other areas of Florida.
The mean content for seven Manatee County wells was 4.52 pCi/1 versus 1.23
pCi/1  in three water table wells.  Geometric mean radium content of the water
table  aquifer in Sarasota County is 15 pCi/1 versus 7.5 pCi/1 in the Floridan.
Potential  radium sources for the water table include shallow phosphate sedi-
ments  and  monazite sands whereas radium in the Floridan aquifer in this area
may  be related to mineralized water in the aquifer and to crystalline basement
rocks  or other strata unrelated to phosphatic zones of current economic
interest.

     The existing  radium-226 data base is marginal in terms of number and
spatial distribution of analyses, particularly for the water table and Upper
Floridan aquifer.  Time series data are nonexistent and study objectives and
techniques for the past decade have been rather inconsistent.  Therefore the
data are not readily compared.  No distinct temporal trend  is apparent in
comparing  individual or grouped observations made in 1966 and those in the
period 1973-1976.  Local contamination associated with specific operations  has
occurred and is  likely to continue as water development and mining expand.
Natural variability in radium content of ground water complicates determination
of background versus contaminated conditions and underscores the need for more
intensive  data collection as an integral part of water and  land management.

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                           SUMMARY AND CONCLUSIONS
1.    Using available radium analyses for the period 1966 to 1976 from a study
     area located in Polk, Hardee, Hillsborough, Desoto, and Manatee Counties
     of central  Florida, nonparametric statistical  tests and graphical  tech-
     niques were utilized to evaluate radium concentrations in three separate
     aquifer systems (water table, Upper Floridan,  Lower Floridan), mineralized
     and nonmineralized areas, and two time periods:   1966 and 1973-1976.
     Geometric mean radium concentration in the water table aquifer in  unmined,
     mineralized areas is 0.17 pCi/1 compared to 0.55 pCi/1 in mined areas.
     For the Upper and Lower Floridan aquifers, average concentratons of
     radium-226 are equal or higher in the control  areas relative to mineral-
     ized or mining areas.

2.    Assessment of dissolved radium-226 in the water table aquifer indicates
     that no significant differences (Mann-Whitney  U test, a = .05) exist
     between areas impacted by mining and those with mineralization, but not
     yet mined.   None of the radium-226 observations available in mined areas
     for the water table aquifer exceed 5 pCi/1.

3.    Assessment of dissolved radium-226 in the Upper Floridan aquifer indicates
     significant differences (Kruskal-Wallis test,  a = .05) between data from
     nonmineralized, mineralized (and mined) and mineralized, unmined areas.
     Using simultaneous multiple comparisons (a = .20), one pair has a  signifi-
     cant difference.  The nonmineralized data have higher radium levels than
     data from areas influenced by mining.  Clearly, detrimental increase
     in radium in the Upper Floridan aquifer is not documented.  Average
     levels for all Upper Floridan aquifer observations are higher than for
     those in the water table aquifer, and similar  to that of the Lower
     Floridan aquifer.

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4.   Comparison of data from mined and nonmined but mineralized areas versus
     data from nonmineralized areas reveals that radium-226 in the Lower
     Floridan is not significantly different (Mann-Whitney U test, a = .05).
     In addition, graphical  analysis of the data suggests that dissolved
     radium in the Lower Floridan may be made up of as many as three separate
     populations, the geometric means of which are 0.7, 3.0, and 10 pCi/1.

5.   Radium-226 data collected in 1966 by the FWPCA and in 1974-1976 by the
     USGS from each of the three aquifers reveals no statistically significant
     difference (Kruskal-Wallis test, a = 0.05 and simultaneous multiple
     comparisons, a = 0.20)  for the decade considered.

6.   Incidence of occasional local contamination (laterally to distances of a
     mile and to depths of several hundred feet) is likely to continue as water
     development and mining expand.  Contamination is generally poorly docu-
     mented due in part to monitoring deficiencies.  Hydrogeologic conditions
     favor entrance of contaminants to at least the water table and Upper
     Floridan aquifers.  Potential contaminant sources include high dissolved
     radium in gypsum pond water and suspended radium in slime ponds.  Entrance
     of contaminants into ground water can occur as a result of sinkhole
     collapse (or similar release) and seepage.  Siting of waste disposal
     facilities in contact with limestone strata of the Hawthorn Formation, in
     particular, fosters contamination problems.

7.   Radium-226 concentrations in ground water of Sarasota County, the secon-
     dary study area, are two orders of magnitude greater than in the primary
     study area for the water table and almost an order of magnitude greater
     for the Floridan aquifer.  Radium in the water table aquifer is signifi-
     cantly greater in the coastal area as opposed to an inland area (Mann-
     Whitney U test, a = .05).  Elevated (relative to Florida and national
     averages) radium-226 levels in both the Floridan and water table aquifers
     are a result of natural enrichment processes, probably related to radium-
     enriched, mineralized ground water deep under the central peninsula but
     at shallow depths in coastal areas, and dissolution of radium-226 from
     the Hawthorn Formation which crops out or is very near the land surface

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     in the western portion of Sarasota County.  Monazite sands in the coastal
     area are a potential source of radium-228 in ground water which warrants
     further monitoring.

8.   Hydrogeologic conditions in the area of phosphate mineralization are
     quite variable and can be favorable or unfavorable for waste disposal.
     The principal variables are the distribution and permeability of car-
     bonate strata in the Hawthorn Formation and the degree of interconnection
     between the Upper and Lower Floridan aquifers.  Disposal of acidic
     chemical processing effluent may induce solution and collapse of car-
     bonate strata and thereby increase contamination.  However, the data to
     support widespread occurrence of this phenomenon are scanty.

 9.  The radiochemical quality of water introduced to the Lower Floridan
     aquifer via recharge wells has only recently begun to be documented.
     Preliminary data from SWFWMD indicate that radium-226 levels are generally
     lower than those in the Lower Floridan aquifer.  The occurrence of at
     least locally high natural concentrations of radium in the shallower
     aquifers requires close monitoring and reporting of such data so that the
     presence or absence of naturally contaminated water in a given mining
     operation is documented by site specific radiochemical data.

10.  Three separate aquifers present in the study area require specific
     monitoring programs to determine baseline and subsequent conditions
     through the reclamation stage.  Until recently there has been excessive
     reliance on use of existing water wells for monitoring water quality in
     the Lower Floridan aquifer.  Data collection typically consists of single
     grab samples and diverse analytical procedures, both of which present
     major limitations to detailed definition of water quality impacts from
     the industry, particularly with respect to the water table and Upper
     Floridan aquifers.

11.  From both temporal and spatial standpoints and in relation to commonly
     recognized objectives for monitoring, the existing radiochemical data
     base is not adequate.  Baseline and contamined water quality in areas of
                                        5

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     mineralization (with  and  without  mining)  is  difficult  to  establish,
     particularly for the  water table  aquifer.   Hydrologic  and geologic data
     collected by industry largely precede  mining and  processing  and thereby
     only partially document  baseline  conditions.   Time  series data  are
     needed,  analytical  procedures should be standardized,  and emphasis should
     be on sampling wells  designed specifically for monitoring.   From a public
     health study standpoint,  existing radium-226 data are  probably  minimally
     adequate to determine the quality of public  water supplies.   Particularly
     in areas of phosphate mineralization and/or  in areas containing monazite
     sands, limited radium-228 data  should  also be  collected for  private  and
     public water supplies to  confirm  whether  the EPA  drinking water standard
     is being met.

12.   Water budget studies  are  recommended to document  seepage  losses from
     gypsum ponds.   Extensive  ground-water  studies  by  industry largely focus
     on the Lower Floridan aquifer and are  designed to determine  effect of
     withdrawal  on  the hydrologic  system for purposes  of justifying  application
     for SWFWMD  consumptive use permits.  Past monitoring of the  water table
     and Upper Floridan  aquifers for contamination  was minimal  but the situa-
     tion is  improving,  largely due  to SWFWMD  requirements.

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                               RECOMMENDATIONS

IMPROVED WASTE DISPOSAL

     Use of lined ponds for gypsum wastes should be required if such facilities
are found to contribute significant radioactivity to ground water.  Regardless,
rainfall exceeds evaporation in Florida, and alternative water removal and/or
recycling may become a necessary part of the control program to prevent the
long-term formation and release of leachate from gypsum piles.  The feasibility
of neutralizing acidic wastes to reduce radium solubility and the potential
for solution collapse of gypsum pond substrates should be investigated.

MONITORING

     Review of recent discussion of ground water quality monitoring method-
ology (Todd et al., 1976) reveals four basic objectives of monitoring:
ambient trend, source, case preparation, and research.  There is little
evidence that any concerted effort with respect to radiochemical contaminants
has ever been put forth in any of the four types.  Particularly lacking,
considering the scale of the phosphate industry, are measurements of ambient
spatial and temporal trends and deviations in relation to standards.  Moni-
toring of effluent quantity and quality factors as potential sources of
ground water contamination are also noticeably absent.

     The reader is referred to extensive discussions by Todd et al. (1976) of
the steps involved in implementing a ground-water monitoring program.   Appli-
cation and tailoring of the conceptual steps to the central Florida setting
and the phosphate industry far exceeds the scope of this report.  However, the
meager knowledge now existing concerning the effects of the industry on shallow
ground water quality is perhaps the most compelling reason to implement needed
studies and related abatement programs in consonance with section 102(a),
104(a), 106(e), and 502(19) of the Federal Water Pollution Control Act (as
amended) and sections 1424(e), 1442(a)(l), 1442(a)(4), and 1442(a)(5) of the
Safe Drinking Water Act.

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     As discussed here,  monitoring denotes a scientifically designed program
of ongoing surveillance  incorporating  direct sampling, inventory of existing
and potential  causes of  change,  analysis  of cause and effect with respect to
water quality, and prediction of future change.   Of key concern with respect
to Florida phosphate mining and  processing is  long-term prediction of the
extent, or at  least the  trend of radium contamination.

     Recommended monitoring during the operation of a mine and related facili-
ties includes  measurement of water levels in piezometers and selected water
wells, water sampling, geophysical  measurements, and maintenance of material
balances, particularly water. The reader is referred to Warner (1974) and
Le Grand (1968) for information  concerning the kind and location of sampling
points, frequency of sampling, measurement of  water levels and geophysical
surveys.  Borehole techniques and electrical  resistivity (Merkel, 1972;
Hackbarth, 1971; Stellar and Roux,  1975)  are deemed particularly suitable for
delineating zones of preferential contaminant  migration and for selection of
monitoring points.

WATER SAMPLING AND ANALYSIS

     1.   Radium-226 data should be routinely  collected from the three princi-
          pal  aquifers in mineralized  (mined and unmined)  areas to ascertain
          temporal  and spatial trends  in  water quality.   Measurement of  other
          parameters such as gross  chemistry,  pH,  fluoride, and suspended/
          dissolved solids is also  recommended.   Concentrations of other
          radionuclides  should also be investigated.

     2.    Wells should be repetitively sampled and a concerted effort should
          be made to resample wells used  in  previous studies.   In this case,
          identical  analytical procedures  should be followed to reduce differ-
          ences due to analytical  techniques.

     3.    Sample collection  and  handling  should  emphasize  field filtration
          followed  by acidification.   Analysis should be for dissolved and
          suspended radium.

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     4.   Sampling of producing wells low in suspended solids is preferable.
          Monitoring wells and piezometers not in daily use should be pumped
          or bailed and allowed to settle shortly before sampling.  Sampling,
          per se, should allow minimal suspended solids to be collected.

HYDROLOGY AND GEOLOGY

     1.   Analysis of lateral and vertical ground-water flow patterns in all
          principal aquifers should precede, accompany, and follow mining,
          waste disposal, and reclamation operations.

     2.   Water budget and material balance studies should be undertaken to
          confirm the magnitude of seepage from gypsum ponds.  Where extensive
          seepage can be documented or where disposal areas are geologically
          unsuitable, corrective action in the form of lining or alternative
          siting  is  recommended.

     3.   Ground-water quality monitoring should be based on analysis of local
          hydrogeologic conditions and should place principal emphasis on the
          water table and Upper Floridan aquifers

     4.   Geochemical investigations are necessary to document the amount,
          kind, and distribution of radioactivity in overburden and matrix
          materials prior to and after mining and waste disposal.   Predictions
          of radionuclide migration from disturbed soil profiles remaining
          after mining and reclamation should be made to assess future radio-
          nuclide content of shallow sediments and contained ground water.
          Kinetics of radium solubility under changed Eh and pH conditions in
          the subsurface are poorly known.  The transport rate for radium in
          the vadose and saturated zones, taking into account dispersion and
          sorption, require much additional  study relevant to the  Florida
          phosphate situation.

     5.   Reasons for and mechanics of sinkhole collapse or other  means whereby
          massive release of slimes and gypsum wastes to the subsurface should

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          be  documented  and  corrective  active  taken,  particularly  considering
          the expansion  of phosphoric acid  production in  Florida.

     6.    Stabilization  of gypsum  piles,  in  particular, also  necessitates
          control  of  infiltration  from  precipitation  in order to prevent
          leachate production  and  subsequent migration  to nearby surface and
          subsurface  water bodies.   Techniques  developed  for  moisture control
          in  common sanitary landfills  and  for  land disposal  of toxic wastes
          should be investigated for their  applicability.

DATA INTERPRETATION AND  REPORTING

     1.    Applications  for mining  and processing  and  periodic interpretive
          written reports  submitted  by  industry should  detail  monitoring
          programs and  results and need for  corrective  action.

     2.    Periodic documented,  reports of  the state of the environment should
          be  prepared by appropriate State  agencies based on  results  of
          industry data  and  other  study programs  conducted by the  State or
          State/Federal  cooperative  efforts.   Emphasis  should be on confirma-
          tion of conditions predicted  in DRI applications, maintenance or
          improvement of desired environmental  conditions, and  identification
          of  short and  long-term benefits and  impacts stemming  from phosphate
          extraction  and related commitments of land  and  water  resources.
                                   10

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                             PROBLEM DESCRIPTION

     Major centers of production for domestic phosphorus are located in
Florida, North Carolina, Tennessee and in the western states of Idaho, Montana,
Wyoming, and Utah.  Total U.S. production of marketable (beneficiated) phos-
phate rock in 1976 was about fifty million short tons, about eighty percent of
which was from Florida (Stowasser, 1976).  The principal area in Florida and
the subject of this report is the land pebble mining district (Figure 1) which
was selected for study because it is the principal existing and potential
producing area in the State and therefore the scene of extensive mining,
chemical processing of phosphoric acid, and land reclamation.  Extensive
ground-water development for irrigated agriculture, the phosphate industry,
and municipal purposes is occurring in the region.

     The multiplicity of Federal interests and actions in the Florida phosphate
industry prompted the Council of Environmental Quality to request and fund
preparation of an environmental impact statement under the auspices of Region
IV of the U.S. Environmental Protection Agency (USEPA).   This report is in
direct support of the overall effort to document present and expected environ-
mental impacts associated with phosphate mining and ore processing in central
Florida.  Other studies by the Office of Radiation Programs address other
aspects including atmospheric releases from processing plants and indoor and
outdoor radiation exposures associated with use of reclaimed phosphate lands
for housing structures.

     The U.S. Environmental Protection Agency (1976a) has issued regulations
concerning the amount of radium in public water supplies.   In terms of drinking
water regulations, radium-226 is lumped with radium-228 and jointly the two
must not exceed 5 pCi/1.  While radium-228 is a beta emitter as opposed to
radium-226, which is an alpha emitter, radium-228 has a chain of alpha-particle
emitting daughters such that the gross alpha particle activity limit for
drinking water is defined to include radium-228.   Furthermore, if water
                                        11

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            :/COUNTIES IN THE
              PRIMARY STUDY AREA
GULF
   A^-_
    OF
     MEXICO
                 HILLSBOROUGH  CO.
                                                     POLK CO.
               MANATEEm CO
                                        HARDEE CO.
                     I|SARASbTA"\J
                                        DESOTO  CO.   j

                           <  ji\SARASOTA COUNTY
                                (SUPPLEMENTARY STUDY AREA)
    Mm''1,''1,  AREA OF AVAILABLE RADIUM-226 DATA
           APPROXIMATE BOUNDARY FOR SIGNIFICANT
           PHOSPHATE MINERALIZATION;
           HACHURES ON MINERALIZED SIDE
           APPROXIMATE LOCATIONS OF
           CITIES AND TOWNS
  Figure 1.  General location map.
                                   12

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contains greater than 5 pCi/1 alpha activity, radium-226 must be determined.
If radium-226 is greater than 3 pCi/1, then radium-228 must be determined.
However, if other information suggests that radium-228 is present, States are
recommended to determine radium-228 and/or radium-226 if gross alpha is greater
than 2 pCi/1 (USEPA, 1976a).

     In the study area, land and water use patterns and management are closely
related to the phosphate industry insofar as mining, beneficiation, and
chemical processing have the potential to adversely affect ground-water
quality through a variety of mechanisms.  Radiochemical species naturally
present can be concentrated and mobilized as a result of mining activity or
waste discharge from mining, processing, or reclamation activities.  Given
this, the objective of this report is to document, using available data,
hydrogeologic and water quality conditions as they passively or actively
relate to the phosphate industry in west-central Florida.  Secondly, there is
a need to identify necessary additional studies and data collection efforts.

     This report summarizes the hydrogeologic situation in a portion of
central Florida as related to phosphate occurrence and, more importantly, to
the potential for ground-water contamination from phosphate mining and pro-
cessing.  Also included is a brief review of the occurrence of radium in
water.  Existing radium (in water) data from central Florida are statistically
analyzed to compare radium concentrations in ground water for 1) mineralized
versus nonmineralized areas and 2) mining/processing areas versus mineralized
but undeveloped areas.  Monitoring efforts to date and resulting data base are
evaluated and recommendations are made concerning needed improvements.

PREVIOUS AND ONGOING INVESTIGATIONS

     Owing to the demands on ground-water resources imposed by the phosphate
industry and other municipal and agricultural  water users in central Florida,
there has been greatly increased interest in the last decade to identify
environmental impacts.  Since 1973, State and regional  agencies within Florida
carefully reviewed applications for mining and other activities affecting the
environment to determine if environmental, social, and economic impacts have

                                        13

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been identified and to rule on the acceptability of such impacts (380.06(06),
Florida Statutes).   Known as Development of Regional Impact (DRI), the review
process is somewhat analogous to an environmental impact statement and is
initiated by the interests proposing development.  Technical documents and
development orders appurtenant to the DRI process constitute site-specific
sources of available information concerning data collection, expected impacts,
and mitigating measures.  Numerous geologic and hydrologic investigations
conducted in central Florida also constitute valuable resource material and
are referred to as appropriate.

     Water quality effects associated with the phosphate industry and areas of
phosphate mineralization has been mentioned in reports by the Federal Water
Pollution Control Administration (Shearer et al., 1966), Battelle Memorial
Institute (1971), Datagraphics, Inc. (1971), U.S. Environmental Protection
Agency (1973; Guimond and Windham, 1975), and most recently the U.S. Geological
Survey (Irwin and Hutchinson, 1976).  The principal  radium-226 data upon which
this report is based include the following:  1) Open file analyses from the
U.S. Geological Survey  (obtained from R. C. Scott, private consultant,
Atascadero, California, formerly with the USGS and USEPA), 2) Scott and
Barker's (1962) study of the distribution of radium in water throughout the
country, 3) an FWPCA survey in 1966 (Shearer et al. , 1966),  Aground-
water sampling by-USEPA from 1973-1976, 5) ground water and surface water
sampling  by the USGS from 1974-1976 (Irwin and Hutchinson, 1976).  The manner
in which these various data bases are used is explained in the section on
water quality.

     Other studies include Osmond's (1964) summary review of the distribution
of uranium and thorium in the rocks and water of Florida.   Williams et al.,
(1965) presented gross alpha data for 280 untreated well water samples from
Florida.   This included 22 samples from 18 shallow wells in the central
Florida phosphate district.
                                        14

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                HYDROGEOLOGIC SETTING OF WEST CENTRAL FLORIDA
GEOLOGY OF CENTRAL FLORIDA

     Geologic investigations of those portions of Polk and Manatee Counties of
interest herein include U.S. Geological  Survey quadrangle reports (Cathcart,
1963a, 1963b, 1963c, 1964, and 1966) and numerous cooperative studies by the
U.S. Geological Survey in cooperation with the Florida Geological Survey
(Peek, 1958; Pride et al., 1966; Stewart, 1966; and Robertson, 1973).
(Note:  Florida Geological Survey is now called Bureau of Geology.)

     The stratigraphic sequence in the study area primarily consists of
gently dipping carbonate bedrock overlain by a thin sequence of clastic and
phosphatic sediments.  Formational names, lithologic descriptions, thickness,
and aquifer makeup are shown in Table 1.  Generalized stratigraphic  cross
sections through the study area are shown in Figures 2 and 3.  In most areas,
the surface material consists of Pleistocene sands, commonly called  terrace
sands, containing varying amounts of organic debris.  In southwest Polk and
adjacent counties, these sands are underlain by the Bone Valley phosphorite
unit, a complex assortment of reworked phosphatic clay,  silt, and sand at
least partly derived from the underlying Hawthorn Formation as a result of
intense lateritic weathering and leaching (Cathcart, 1964).  The lowest unit
consists of a basal phosphatic conglomerate much enriched in phosphate (Hoppe,
1976) and usually part of the phosphate ore zone which is locally called
matrix.  The Bone Valley unit thins or is absent in northern and eastern Polk
County but is prominent throughout much of southwestern  Polk County  and
adjacent areas in Hillsborough, Manatee, DeSoto, and Hardee Counties.  The
gentle southerly dip (Cathcart and McGreevy, 1959) results in deeper burial in
these latter areas.

     Underlying the Bone Valley unit is a phosphatic, interbedded sequence of
limestone, dolomite, sand, sandy clay, and gray clay known as the Hawthorn
                                     15

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                    TABLE  1.   GEOLOGIC  AND  HYDROGEOLOGIC UNITS  IN CENTRAL FLORIDA
GEOLOGICAL
AGE
PLEISTOCENE
PLIOCENE
MIDDLE MIOCENE
EARLY MIOCENE
LATE OLIGOCENE
LATE EOCENE
FORMATION
TERRACE DEPOSITS
01
BONE VALLEY
FORMATION
Tb
o>
CL
a.
=J
Tbu
1
Tbl
HAWTHORN FORMATION
Th
TAMPA FORMATION
Tl
SUWANNEE LIMESTONE
Ts
OCALA GROUP
To
LITHOLOGICAL DESCRIPTION
UNWEATHERED
UNCONSOLIDATED QUARTZ
SAND WITH ORGANIC DEBRIS
RED & WHITE MOTTLED SANDY
CLAY: GREY AND TAN SAND.
CLAYEY; SCATTERED PHOSPHATIC
NODULES INCREASING TOWARD BASE
SANDY, CLAYEY GREY & GREY
GREEN PHOSPHORITE: NODULES
SAND TO GRANULE SIZE. LOCAL
BASAL PHOSPHATIC CONGLOMERATE
OLIVE GREEN. GREY BROWN
CLAYEY SANDSTONE WITH
NODULES TO A BUFF. WHITE
LIMESTONE WITH NODULES
AT BASE. DOLOMITIZED
LIGHT YELLOW. SANDY AND
CLAYEY LIMESTONE: BROWN
BLACK PHOSPHATIC NODULES
MAY BE CLAYEY SAND
FOSSILIFEROUS CREAM OR
TAN LIMESTONE: VERY SOFT
GRANULAR DETRITAL
WHITE, GREY. CREAM OR TAN
SOFT GRANULAR LIMESTONE
OF HIGH PURITY: OOLOMITIZED
ALSO SOFT, CHALKY
WEATHERED
LOOSE QUARTZ SAND. SWAMP
DEBRIS
WHITE SAND. TRACE OF CLAY
WITH SCATTERED DULL WHITE
PHOSPHATIC NODULES PARTICULARLY
AT BASE
WHITE SAND. VESICULAR
WITH DULL WHITE
PHOSPHATE GRADING DOWNWARD
TO GREY OR GREY-GREEN SAND
CLAYEY OR SANDY CLAY WITH
NUMEROUS NODULES.
CALCAREOUS SANDY CLAY
WITH BROWN OR BLACK
PHOSPHATIC NODULES WITH
POSSIBLE GRADATION TO LIME-
STONE AT DEPTH
CALCAREOUS SANDY CLAY
CONTAINING SCATTERED
PHOSPHATIC NODULES
NEAR SURFACE OCCURENCE
TENDS TO BE SILICIFIED
SILICIFIEO TO HARD.
GREY TO WHITE CHERT.
THICKNESS
(It.)
0-65
P!:0-25
M3:0-35
ItatalTb)
P:0-35
P:0-130
M:l 50-350
P:10-80
M:150-175
P:80-120
M:150-300
P: 125-270
M:300-325
AQUIFER
wr
WT
UA<
P:UFS
M:UF or
LF6
P:UF
M:UF or
LF
LF
LF
ROLE IN PHOSPHATE
DEPOSITS
NO DIRECT ROLE NOTED
INTENSE LATERITIC WEATHERING
USUALLY DEPLETED IN PHOSPHATE
BASAL CONGLOMERATE GREATLY
ENRICHED IN PHOSPHORUS DURING
INTENSE WEATHERING OF HAWTHORN
PRINCIPAL ORE COMPONENT IN
POLK CO.
PARENT MATERIAL, IN PART. FOR
BONE VALLEY.IRREGULAR UPPER
SURFACE BECOMES IMPORTANT
ORE IN MANATEE CO.
SOME RESIDUAL CLAY PRESENT
FROM WEATHERING EVENTS WHICH
ENRICHED ORE WHEN UPPER
HAWTHORN ABSENT. NOT ORE
NO DIRECT ROLE NOTED
NO DIRECT ROLE NOTED
'NONARTESiAN 'POLK COUNTY 'MANATEE COUNTY 'UPPER MOST ARTESIAN 'UPPER FLORIOAN ARTESIAN 'LOWER FLORIDAN ARTESIAN

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                                             ^DIFFERENTIATED
                                                              FORMATION
                                                              -H	'"~r
                                                              FORMATION
                                                              LIMESTONE
                                                                	-L-
                                                                                         01  2345 MILES

                                                                                      VERTICAL EXAGGERATION <105
                                         SECTION IN POLK AND HARDEE COUNTIES ADAPTED  FROM STEWART(1966) AND
                                         WILSON (1975), RESPECTIVELY.  WELLS ARE  IDENTIFIED  ACCORDING TO THE
                                         DESIGNATION USED IN THESE REPORTS.  TRACE OF CROSS SECTION SHOWN ON
                                         FIGURE
Figure 2.  Generalized geologic cross section through southern Polk and northern  Hardee  Counties

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                                              MANATEE RIVER    TERRACE SANDS
                                                      M-8       	\	
                                                         BONE VALLEY FORMATION
                                                               Tjnconformlty
                                                                                 NORTH FORK
                                                                               MANATEE RIVER
                                                           HAWTHORN FORMATION
                                                                unconformity"

                                                             TAMPA FORMATION

                                                                unconformity-
                                                           SUWANNEE LIMESTONE


                                                                unconformity-




                                                               OCALA GROUP



                                                                unconformity"

                                                           AVON PARK LIMESTONE
--MSL
See Figure 7. for trace of cross section. Formation contact elevations were derived from structure contour maps, thickness data, and well logs presented by Peek(1958). Wells
M-12, M-8 etc.are shown for orientation purposes only as these are shallow wells.

    Figure 3.   Generalized geologic  cross  section  through northeastern  Manatee County.

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Formation (Cathcart, 1963a) which is generally present south of the Alafia
River and west of the Highlands Ridge.   It is present in Polk, Hillsborough,
Hardee, DeSoto, Charlotte, Manatee, and Sarasota Counties (Cathcart and
McGreevy, 1959; Stewart, 1966; Wilson,  1975).  A source for part of the Bone
Valley, the Hawthorn has an irregular upper surface and is sometimes suffi-
ciently enriched in phosphate to constitute part of the matrix (Hoppe, 1976).
In Manatee County the Hawthorn contains more clastic materials and is thicker
relative to the section in Polk County (Cathcart, 1963a).  From east to west,
it becomes increasingly silty as well.   At the Swift Chemical Company phosphate
mine area in northeastern Manatee County, the Hawthorn is predominantly silt
whereas in Hardee County it is characterized by clay.

     Southward in Manatee County and particularly in the area of the Manatee-
Sarasota County line, the Hawthorn is exposed or quite shallow, rather clayey,
and the principal source of phosphate ore.  Phosphate deposits, presumably
from the Hawthorn, are exposed in the banks of the Intercoastal Waterway Canal
in the area of Casey Paso.  Much of Sarasota County is underlain by phosphatic
sediment beneath twenty feet or less overburden which thins or is absent to
the west.

     The Tampa Formation which underlies the Hawthorn Formation was originally
identified (Parker et al., 1955) from subsurface data in the Tampa area where
the unit is predominantly limestone and a prominent aquifer in the Floridan
aquifer system.  Elsewhere in central Florida and particularly in southern
Polk County and adjacent portions of Hillsborough, Manatee and Hardee Counties,
clastic materials are common in the lower part of the Tampa which acts as a
confining layer.  Use of the term "Tampa Formation" was recommended by Parker
(Geraghty and Miller, Inc., personal communication, February 25, 1977) and is
so used herein.

     The lithological sequence of the Tampa Formation and its role in the
Floridan Aquifer system in central Florida has been debated for many years.
It is generally considered a limestone in which there occurs a confining
clayey member.  Stewart (1966) contended that the clay unit is at the top of
the Tampa.  However, Wilson's (1975) study of Hardee and DeSoto Counties
                                   19

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revealed a persistent and extensive clay and silt unit at the bottom of the
Tampa Formation.   This is generally believed to be true in southern and
southwestern Polk County as well, where the Tampa Formation is present only as
a clayey unit (B. Boatwright, Southwest Florida Water Management District,
personal communication, February 16, 1977).  It is absent in northern Polk
County (Pride et al., 1966).  In Manatee County and the western third of
Hardee County it is largely made up of carbonates (Wilson, 1975) at least in
part equivalent to the clay and silt member present in Polk and Hardee Counties
In Manatee County the clay and silt member is believed present only in the
northeast corner (based on extension of the trends reported in Hardee County
by Wilson, 1975).  The Tampa Formation generally dips south or southeast in
Polk County (Stewart, 1966) and to the southwest in Manatee County (Peek,
1958).

AQUIFER SYSTEMS AND GROUND-WATER FLOW

     For the purpose of this report three principal aquifers are defined in
the  study area:  The Upper and Lower Floridan aquifers which are typically
confined and an unconfined local shallow aquifer.  These are schematically
shown in Figure 4 which also depicts the principal geologic units present.
The  degree of interconnection between aquifers is highly variable with location
and, in effect, creates the  large Floridan aquifer system which is made up of
a series of aquifers and confining layers.  The most prolific aquifer is the
Avon Park Limestone.   The initial discussion which follows is applicable
primarily to Polk County and immediately adjacent portions of Hillsborough,
Manatee, and Hardee Counties.

     Unconfined or water table conditions occur in the unconsolidated surficial
sediments and locally may extend to the lower part of the Hawthorn Formation.
The  Floridan aquifer system, composed of at least five major stratigraphic
units and individual  aquifers, includes the Upper and Lower Floridan aquifers
as defined herein.   In most of the study area the Lower Hawthorn and the Upper
Tampa belong to the Upper Floridan aquifer which is sporadically distributed
and variable with respect to head, yield characteristics and water quality.
In northeastern Manatee County at the Swift Chemical Company mine site and at
                                   20

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                             CENTRAL MANATEE CO.
                                                                           CENTRAL POLK CO.
ro
           WATER TABLE
          	AQUIFER	

           AQUITARD
         UPPER FLORIDAN
            AQUIFER
           .AQUITARD.
        LOWER FLORIDAN
            AQUIFER
TERRACE SANDS

 BONE VALLEY
 FORMATION

  HAWTHORN
  FORMATION


   TAMPA
  FORMATION

  SUWANNEE
  LIMESTONE
    OCALA
    GROUP
                                                            PREDOMINANTLY LIMESTONE AND DOLOMITE
                                                             NOT TO SCALE
    LEGEND

Direction of ground-water flow

Water table position

Carbonate bedrock
        (limestone,dolomite)

Clay, silty clay
   Figure 4.   Generalized  southwest-northeast  hydrogeologic cross section through Polk and  Manatee Counties

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the Phillips site in Desota County,  a distinct Upper Flon'dan aquifer is not
present (B.  Boatwright,   Southwest Florida Hater Management District, written
communication, June 6,  1977).   Successively deeper carbonate units below the
Tampa are part of the Lower Floridan aquifer which extends throughout most of
central Florida.   The Lower Floridan is typically under artesian pressure and
water encountered in a bore hole penetrating a given aquifer will rise above
the elevation of the stratigraphic boundary between the aquifer and overlying
units.  In certain instances the rise is sufficient to allow water to flow to
the land surface but this condition  now exists in only a few areas.  Because
of heavy pumping, particularly in southwestern Polk County and Southwestern
Hardee County, water levels or head  in the Lower Floridan are falling.  Under
completely natural conditions they were generally also below those in shallower
aquifers except in areas where there were or are flowing wells developed in
the Lower Floridan.  Pumping, therefore, is causing increased downward flow in
much of the study area.

     The foregoing explanation is highly simplified and is probably applicable
only to that portion of the study area in Polk County and immediately adjacent
portions of Hillsborough, Manatee, and DeSoto  Counties.  Aquifer boundary
conditions are largely stratigraphic and therefore variable depending on the
persistence of lateral and vertical  successions and structural controls.  For
example, stratigraphic relationships of the surficial sand unit and the
lithologic makeup of the Hawthorn are very influential in determining the
amount of recharge to the latter and whether it constitutes an aquifer or a
semi-confining unit.  Similarly, development of solution channels and other
karst features in the Hawthorn and Upper Tampa Formations determine in part
the amount of recharge from local precipitation or other hydrologic events at
the land surface.  Where the Hawthorn is thick and areally extensive, karst is
not well developed.  For Sarasota and Manatee Counties, separation of the
Upper and Lower Floridan aquifers is generally not possible.  In large part
this is due to scarcity of stratigraphic and hydraulic information and because
the limited facies data available (Wilson, 1975) indicate different conditions
than the area to the northeast.

     Structural elements in Polk and Manatee Counties are not topographically
prominent but may play important roles in ground-water occurrence and movement
                                    22

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in the Floridan aquifer system.  The principal structural element in central
Florida is the north-trending Peninsular Arch which is east of Polk County.
Along the west flank of the arch is the Ocala Uplift, the south end of which
extends into northern Polk County (Figures 8 and 9, in_ Pride et al., 1966).
The Ocala Uplift imposes both hydrologic and geologic control on ground water
in central Florida.  The elevated position of the arch over geologic time
allowed erosion and/or non-deposition, thereby positioning more permeable
carbonate units at or near the land surface.  This facilitates increased
recharge.  In addition to the stratigraphic framework, lateral and vertical
controls on flow include paleokarst and fault planes associated with uplift,
deposition/erosion cycles, and paleo-weathering features.  Flanking the
highland area at depth are less permeable materials which act as semi-confining
units and aid in the creation of artesian conditions.  The combination of
increased recharge, elevated topographic position, stratigraphic boundary
conditions, and regional dips generally to the south, southeast, or southwest
gives rise to artesian conditions in the Floridan aquifer, and to a more local
extent, in the basal limestone of the Hawthorn Formation.  Most of the fore-
going features are schematically shown in Figure 4.

INFLUENCE OF MINING AND PROCESSING

     Strip mining and chemical processing as practiced in Florida's central
phosphate district can affect ground-water as a result of activities associated
with three broad categories: 1) pre-mining site preparation, 2) waste disposal
related to ore extraction/beneficiation/chemical processing, and 3) post-
mining site reclamation and slime pond or gypsum pond maintenance.  Figure 5
shows the major operations involved in mining.  By convention within the
industry, the term mining includes beneficiation.  Overburden consisting of
surficial sand and the Bone Valley unit is stripped with draglines to expose
the matrix.  Water pumped from the pits or recycled from the slime ponds,
supplemented with water from the Floridan aquifer, is used to convert the
matrix to a slurry which is pumped to the beneficiation plant.  There, screens
and flotations separate the phosphate from the sand and slime tailings which
are piped to disposal ponds.  Makeup water is obtained primarily from deep
wells and from water added to the system as precipitation, ground-water
inflow, or matrix moisture.  Mining may go as deep as the carbonate unit
                                   23

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         DEWATERING
            WELLS
CONNECTOR (PUMPED)
PRESENT WATER TABLE
                                       TERRACE SANDS OR
                                  QUATERNARY CLASTIC DEPOSITS
                    QVERBURDEN
                                                            ACTIVE  INING
 NAREA BEING OEWATERED
   \PRJOR TO MINING
                                                        - - - -^7-e-j T- ~^J-  T-L
                                                          - ,    I  /I	i	 	    	  
                               POTENTIOMETRIC SURFACE
                                  UPPER FLORIDAN     '
                . .\\\ J s i^=\
                                                                           .
                                                                          T.....-TAMPA FM.
                               POTEsmOMETRIC SURFACE
                             '  	'LOWER FLORIDAN f
                                                   SURFICIALnB WATER
                                            ORE\^ (  AQUIFER UK TABLE
                                                                                              UPPER
                                                                                            FLORIDAN
                                                                                             AQUIFER
                                                    LOWER
                                                   FLORIDAN
                                                   AQUIFER
                                                                            NOT TO SCALE
             Figure 5.   Interaction  of mining  operations  and the  hydrogeologic system.

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of the Hawthorn Formation.  After stripping the ore, overburden  is replaced
and shallow ground-water  levels, drawn down to allow mining, gradually recover

     The stratigraphic units affected by excavation are shown  in Figure 5.
Also shown are the water  table and Upper Floridan aquifers, wells used for
water supply and dewatering, and water table position.  Due to nonuniform
limestone distribution in the Hawthorn Formation and differences in the verti-
cal extent of phosphatic  matrix, many or even most mines are not likely to
extend to the uppermost beds of the Floridan aquifer.  In certain areas of
active mining, particularly in Polk County, shallow confining materials may be
removed and increased recharge to the Floridan aquifer may occur.  Another
suspected but poorly documented source of recharge results from occasional
sinkhole collapse beneath slime or gypsum ponds.  In the case of the latter,
dissolution of carbonate  strata in contact with acidic gypsum pond water may
be a factor.  Only one case of such a collapse is known and a few others are
suspect.  Cavities are not always present and collapse incidence is believed
to be low.  Remote sensing data indicate that seepage through sand tailings
dams containing gypsum ponds is common (Coker, 1971; 1972).

     Use of connector wells is typified by the International Minerals and
Chemical Corporation (IMC) installation at the Kingsford mine of more than 50
such wells completed in the surface aquifer and in the underlying Floridan
aquifer (Hoppe, 1976).  Cathcart (USGS, personal communication, Februarys,
1977) indicates this practice has become widely used as it is an effective
method to dewater the ore zone and sand cover prior to mining.   Dewatering is
not always necessary depending on the depth to water relative to the base
of the ore body and the type of mining operation.   Because of declining heads
in the Lower Floridan aquifer, recharge via connector wells is  beneficial  with
respect to the water supply picture.  Credit is given for the amount of water
recharged, thereby allowing more pumping from the Lower Floridan than if only
natural  recharge occurred.  The IMC recharge program also includes 60 observa-
tion wells and 20 surface monitoring stations to preclude introduction of low
quality waters to the Floridan aquifer (Hoppe, 1976).  As head  in the Floridan
aquifer decreases in areas of heavy pumping, head differential  relative to
shallow aquifers will increase and recharge wells will  become increasingly

                                        25

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popular.   In the past more use was made of pumped wells or pits to effect
dewatering.   Water was discharged into adjacent pits or discharged to surface
water courses.   The latter practice is not favored because water is exported
from the basin  rather than being used to replenish ground-water resources,
particularly the Floridan aquifer system.

     Stripping  of the overburden and leach zone and subsequent removal of the
phosphate ore or matrix with draglines thoroughly disrupts the natural sequence
of overburden, leach zone and matrix.  Although a leach zone is not always
present it  is significant from a radiation standpoint because it is believed
to contain  the greatest concentration of uranium (Golden, 1968).  Formerly,
overburden  and leach zone materials were dumped on vacant ground adjacent to
the trench  to allow removal of the matrix.  As successive parallel trenches
are cut, the overburden and leach zone materials are put into adjacent, mined-
out cuts.   In recent years, overburden and leach zone materials are separated
so that overburden is replaced last.  Ore is hydraulically disaggregated in an
open pit and pumped to a washer plant as slurry containing about 40 percent
solids.  For a typical mine, about 400 acres/year will be stripped, resulting
in the use  of 4.5 billion gallons of water for slurry makeup.

     Water  utilization, primarily from the Floridan aquifer, has caused
significant decline in the potentiometric surface of the Floridan aquifer
between 1964 and the present.  In central  Florida approximately sixty percent
of the water pumped from the Lower Floridan aquifer is for irrigation and
about twenty percent for the phosphate industry.  Municipal use accounts for
the balance.  Introduction of new techniques for beneficiation have reduced
the phosphate water usage and at least one company, Brewster Phosphates, Inc.,
is operating without need for water withdrawal from the Lower Floridan aquifer.

     The recent configuration of the potentiometric surface in the Floridan
aquifer is  represented in maps prepared by the U.S. Geological Survey and the
Southwest Florida Water Management District (Stewart et al., 1971; Mills and
Laughlin, 1976).  Significant potentiometric troughs are centered in the area
due north of Bartow, as well as in north-central Manatee County and north-
western Sarasota County.  The latter two troughs developed in the period

                                        26

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1969-1975 and are probably related to irrigated agriculture as the phosphate
industry does not operate in these areas.

     Over much of the central Florida study area, the vertical flow gradient
has been downward although there are areas along the coast and along the Peace
River where gradients are or were upward.  With heavy pumping and steepened
downward flow gradients there is increased potential for downward movement of
shallow ground water.  Increasingly active monitoring of shallow and deep
ground water is now required by the Southwest Florida Water Management District
and as a part of the development orders appurtenant to the DRI process.

     Drainage water associated with mines is not usually discharged to surface
streams.  Although mine water and ambient ground water are intimately associ-
ated, the 1973 USEPA study revealed that recirculated water (tail water from
slime ponds) and pit seepage at two mines in Florida contained only 0.28 to
1.5 pCi/1 dissolved radium-226.  In comparison, leachate from gypsum spoil
piles at chemical processing plants contains 60 to 100 pCi/1.   It would appear
that potential adverse effects on ground-water quality would primarily be a
result of chemical processing (to produce phophoric acid) and accompanying
waste handling featuring gypsum ponds and piled gypsum waste.

     Ore beneficiation utilizes recycled slime pond water supplemented with
deep ground water.  Tailings and slime are emplaced in specially constructed
settling basins and mined out pits.  Although the ratio varies depending on
ore grade, a general guide is that a ton each of sand tailings and slime is
generated per ton of phosphate rock product.  One of the critical problems  the
phosphate industry faces is dewatering large amounts of clay slime which now
requires substantial funds for dam construction, maintenance,  and monitoring
because solids remain in suspension and/or will not dewater.   As a result the
slime ponds not only commit a large amount of otherwise usable water and land,
but also are potential sources of radiochemical and other pollutants that can
affect nearby water resources.  Recent and ongoing studies funded by the U.S.
Bureau of Mines, in particular, show that accelerated settlement of slimes  is
economically feasible.  One of the more promising methods involves mixing sand
and slime fractions to increase settling and water expulsion.

                                        27

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     As the number and/or capacity of chemical  processing  plants  increases,
attendant gypsum piles and acidic effluent may  pose increasing  problems with
respect to long-term stabilization of wastes.   Both the effluent  and the
gypsum are elevated in radium,  necessitating long-term stabilization to
prevent leachate formation and  migration.   No monitoring studies  are available
detailing ground-water quality  around such piles  or stabilization techniques
for the pile proper.   One pond  near Mulberry failed by sinkhole collapse in
1975 and a study by Zellars and Williams  (1977)  showed average  leakage of 13
percent or 2039 gallons per minute for two years  of record at two mines and
one year at a third.   The amount of leakage from  gypsum ponds is  unknown.
                                       28

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                        SOURCE TERM CHARACTERIZATION

     "Phosphate rock" is a commercial term denoting a rock with one or more
phosphate minerals and of sufficient enrichment and composition to be usable
as is or after concentration.  In Florida, the principal ore is phosphatized
limestone.

     The principal phosphorus-bearing minerals in the central Florida phos-
phate deposits are in the carbonate apatite group with the general formula:
Cag (PO,)o(F,Cl ,OH).  Phosphate exchanges with small quantities of VO,, AsO*,
and SO, whereas Na, Si, Th, U, and rare earths can exchange with Ca.  Such
replacement plus the cryptocrystalline structure gives rise to the term cello-
phane, indicative of a nondefinitive suite of carbonate apatite minerals which
are the essential minerals of phosphorite (sedimentary phosphate rock).
Uranium, vanadium, selenium, chromium, and rare earths can be present in
sufficient concentrations to constitute actual or potential by-products.

     Natural uranium, present in Florida phosphate deposits in concentrations
of 0.1 to 0.4 pounds per ton (Stowasser, 1976), consists of approximately 99.3
percent (by mass) uranium-238.  Radioactive decay of uranium-238, commonly
known as the uranium series, gives rise to uranium-234, thorium-230, radium-
226, and radon-222, amongst others.  For reasons of half life, toxicity and
mobility not all members of the decay series, which ends with the formation of
(stable) lead-206, present equal hazard.  Although all radiation exposure is
considered harmful and adverse effects are assumed proportional  to dose
(linear, no threshold hypothesis).  Radium-226 is singled out because of its
known occurrence in areas of phosphate mineralization.  It is long lived (1600
years), has relatively high transfer from the gastrointestinal tract to the
blood, and has an affinity for bone where it replaces calcium and is toxic dye
to high energy alpha decay characteristics.  Study is also facilitated by the
data base from sampling efforts in the last decade and particularly from 1973-
1976.  Uranium and principal progeny are in secular equilibrium in the matrix

                                       29

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(Guimond and Windham,  1975)  and presumably in the leach zone as well.   Elevated
levels of radon in structures  built on reclaimed land (U.S.  Environmental
Protection Agency, 1975;  and 1976b; Fitzgerald et al.,  1976) suggest that
uranium and radium distribution in shallow depths may be increased relative to
pre-mining levels.  Presumably this occurs if leach zone materials are mixed
with other overburden  materials as part of overall  reclamation.  What effect
weathering and leaching from rainfall  may have on redistributing radioactivity
in the subsurface has  not been determined and is of legitimate concern, partic-
ularly with respect to long  term water quality in the water table aquifer.

     Before discussing various liquid  and solid wastes  associated with phos-
phate mining and processing, some description of basic  operations may be
useful.  After the overburden  is stripped, ore is excavated by draglines,  put
into slurry form with  hydraulic jets,  and pumped to nearby washing plants  for
size separation.  Minus-200  mesh particles or slimes  are discharged to slime
ponds for settling to  allow  reuse of water.   Slimes amount to about one-third
of the original ore volume and represent about one-third of the total  mineral
values extracted.  In  addition they are costly to handle and store.  Slime
production from Florida alone  is estimated at 36.3 million short tons  in 1973
(Guimond and Windham,  1975).  Estimated radium content  is 1480 Curies.  Slimes
are potentially damaging to  water resources  as a result of entrance to ground
water reservoirs or dike failure and release to streams.  Reported radium-226
in Florida slimes is 45 pCi/g  versus 42 pCi/g in phosphate products (Guimond
and Windham, 1975).

     After separation  from the ore, sand tailings are 1) piped to sand piles
as a slurry, 2) used to build  up dikes around slime ponds, and 3) placed in
mined out areas.  Because sand tailings yield water readily, there is  increased
interest in using them to assist in slime stabilization or to bury them in
mined out areas where  their  permeability can be used to store and transmit
ground water for use in ore  transport  and beneficiation.  Amine flotation
water used for sand separation is discharged to mine pits and recycled.
Radium content of sand tailings is rather low, averaging 7.5 pCi/g.  Radio-
activity primarily is  associated with  the phosphate fraction, one-third of
which is slime waste and two-thirds product.  Approximately 380 Curies of

                                       30

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radium-226 in 55.8 million short tons of tailings were generated in Florida
alone in 1973 (Guimond and Windham, 1975).

     Phosphate rock separated from the ore is either exported or sent to a
chemical processing plant for conversion to superphosphate by treating finely
ground phosphate rock with sulfuric acid:
      tricalciurn  sulfuric         monocalcium               gypsum
      phosphate     acid            phosphate

     The product of the above reaction is superphosphate.  Monocalcium phos-
phate is soluble in water and therefore plant available.  Gypsum remains in
the product and dilutes it.  Phosphoric acid is produced by adding additional
sulfuric acid and separating phosphoric acid from the gypsum according to the
reaction:

     Ca1()F2(P04)6 + 10 H2S04 + 20 H20 = 10 CaS04- 2H20 + 2 HF + 6 H3P04

Phosphoric acid can be reacted with additional phosphate rock to yield triple
superphosphate which contains 45 to 48 percent PO^C-  ^n the above reaction,
large piles of gypsum and ponds of acidic effluents result.  Production of
other fertilizers such as diammonium phosphate, urea-ammonium phosphate, or
"complete" fertilizers consisting of phosphorus, nitrogen, and potassium
compounds is increasing due to market demand and favorable transportation
economics.

     Radionuclide concentrations in product, slime, and sand tailings mater-
ials from Florida phosphate deposits were determined in previous USEPA studies
(1973; and Guimond and Windham, 1975).  These, in turn, were expansions of the
work begun by Spalding (1972) of the Texas A & M Oceanography Department.
Data presented by Guimond and Windham (1975) show that beneficiation processes
do not alter the isotopic ratios, which are essentially in secular equilibrium
for the uranium, actinium, and thorium decay series.  However, redistribution
of radionuclide concentrations occurs among the three principal fractions
                                        31

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cited.   Uranium occurs as a trace element in the phosphate-bearing minerals,
hence it tends to remain with the fertilizer, whereas most of the radium is
concentrated in the solid and liquid wastes.  Phosphoric acid is enriched in
radium-226, uranium, and thorium relative to the concentration of phosphate
deposits.  The sand tailings fraction contains about 12 percent of the total
radioactivity, whereas the slime and product fractions contain 48 percent to
40 percent, respectively.  Overall,  about 60 percent of the activity, which in
1973 amounted to over a thousand Curies each of radium-226, uranium-234 and -
238, and thorium-230, is contained in the slime and sand tailings (Guimond and
Windham, 1975, Table 2).

     Radium concentrations are greatest in gypsum wastes associated with
phosphoric acid plants (U.S. Environmental Protection Agency, 1973; Guimond
and Windham, 1975).  Whereas seepage into mine pits and recirculated mine
water contained 0.28 to 1.5 pCi/1 dissolved radium-226, gypsum water at four
separate fertilizer plants ranged from about 50 pCi/1 for plants without
recycling and 90 to 100 pCi/1 in those that did (U.S. Environmental Protection
Agency, 1973).  By-product gypsum from central Florida acid plants contains 21
to 33 pCi/g radium-226 compared to 45 pCi/g in washer plant slimes and 42
pCi/g in phosphate rock product.  Gypsum solubility and high rainfall (50
inches per year) indicate continuing measures will  be necessary to control
leachate production and migration from such piles.   It is recommended that
techniques developed for moisture control in common sanitary landfills and for
land disposal of toxic wastes, including uranium mill tailings, be investigated
for their applicability to gypsum piles.  Additional  measures are necessary
for treatment and immobilization of the liquid fractions.

     Dissolved radium-226 in slime pond influents and discharges consistently
averages less than 5 pCi/1 and typically less than  2 pCi/1 (U.S. Environmental
Protection Agency, 1973; Guimond and Windham, 1975).   Radium in the suspended
fraction of the influents is more variable, ranging from 9.8 to 72.6 pCi/g
(mean 33.5) on a weight basis and 10.2 to 2248 pCi/1  (mean 673) on a volumetric
basis.   The latter is highly dependent on the amount of suspended solids in
the slime discharge.  In effect, radium content on  a per unit weight (of
undissolved solids) basis varies by a factor of seven, whereas the quantity of
undissolved solids varies by a factor of 220.  Total  radium that potentially
                                   32

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could contaminate ground water  is therefore quite variable and  suspended
solids content is the more significant contributor.  Analysis for  "dissolved"
versus "undissolved" radium  is  highly dependent on the  pre-analysis methods.
Acidification followed by filtration, wet chemistry, and counting  will give a
higher content of dissolved,  radium and a lower content  of undissolved radium
relative to methods calling  for filtration first.  More importantly, the
amount of suspended and settleable solids in a given sample can greatly affect
the analytical results.  Thus it is apparent that ground-water monitoring for
suspected or actual contamination in the vicinity of a  gypsum pond or slime
pond, or monitoring of ground water from mineralized stratigraphic intervals
calls for different procedures  than in the case of a public health related
survey involving water supply wells.  This point will be developed further in
a subsequent section.

     On the basis of available  grab sampling data,radium solubility does not
appear to increase as a result  of residence time or other conditions in slime
ponds.  Dissolved radium in  discharges ranged from 0.02 to 2.2 pCi/1
and total radium (dissolved  + undissolved, pCi/1) never exceeded 3.0 pCi/1 at
any one facility.  Seepage to ground water, however, may contain higher total
radium depending on the transport route (conduit versus intergranular seepage)
and the suspended solids content of the wastewater.

     In summary, seepage, overflows, and accidental releases from the various
basins and pits put the wastes  in actual or potential contact with adjacent
water resources.  Although one  can only speculate on the basis of very limited
available data, mining practices probably introduce marked changes in the
chemical  and hydrologic stability characterizing the ore body and associated
overburden and leach zone.   The effects, if any, on increased leaching of
radionuclide-bearing minerals are unknown.   From a ground-water protection
standpoint, intergranular seepage from slime ponds would not be expected to
grossly change radium concentrations in native ground water, particularly in
the unconfined aquifer.  However, movement of slimes high in suspended solids
into solution cavities and other secondary permeability features could result
in contamination.  Sampling  of such contamination using methods whereby acidi-
fication  is followed by filtration will give anomalously high results for
                                    33

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dissolved radium.   Measurement of the suspended solids content and radio-
chemical character thereof as well  as dissolved radium should be incorporated
in monitoring studies of slime pond seepage to ascertain the degree of natural
filtering and the prevalence of turbid seepage, if any.  Wells completed in
the upper limestone unit and situated at or very near pond perimeters are
recommended.

     Field and laboratory studies by Guimond and Windham (1975) of phosphoric
acid plant waste treatment using basic solutions containing quick lime,
hydrated lime, limestone, or dolomite indicate the feasibility of removing at
least 94 percent of soluble radium-226.   Use of the double liming procedure to
markedly reduce dissolved radium was also recommended in a previous USEPA
(1973)  study.  Coprecipitation of radium in calcium-radium sulfate appears to
be the  removal mechanism which is facilitated by abundance of calcium, sulfate
and phosphate ions, reduced solubility of radium sulfate at neutral or near-
neutral pH, and settling of precipitates.  In this way, process water contain-
ing 60  to 90 pCi/1 of dissolved radium can be treated so as to reduce concen-
trations to between 1 and 3 pCi/1.   Neutralization of acidic effluents would
greatly reduce soluble radium content.  Whether such effluents actually
dissolve carbonate strata beneath gypsum ponds and thereby increase incidence
of solution cavity collapse/development is unknown.  If additional study
confirms such dissolution, there is additional reason for treating the wastes.

SOURCES OF RADIOCHEMICAL DATA

     Analytical data for radium-226 in water were primarily obtained from the
following sources: 1) U.S. Environmental Protection Agency, 2)  Federal Water
Pollution Control Administration and 3)  U.S. Geological Survey   These data
are tabulated in Appendices 1, 2, and 4.  Radium and gross alpha data were
also obtained from the Southwest Florida Water Management District and from
preciously published reports on radium in Florida and the United States.
Table 2 summarizes the data sources, number of analyses, time of collection,
and how the data are used in this report.  Only an approximate tally of
analyses actually used is possible.  For example, the 1966 survey by FWPCA
produced data for 105 sampling points, all of which are listed in Appendix 2.
Only about 40 of these had sufficient well information or were properly located
                                   34

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                                                TABLE  2.   SUMMARY  OF  PRINCIPAL SOURCES OF RADIUM-226 DATA
SOURCE
USEPA
USGS - Irwin and
Hutchinson, 1976

USGS - Scott and
Barker, 1962

USEPA (for
Sarasota County
Health Department)
FWPCA - Shearer
et al. , 1966
TIME OF
CULLECTION
1973-1975
1974-1976
1974-1976
1954-1957
1954-1957
1954-1957
1975-1976
1966
UTILIZATION IN
PRESENT STUDY
Analyze spatial
variation
Analyze spatial
variation

Analyze spatial
variation

Analyze spatial
variation
Analyze spatial
variation
NUMBER OF
OBSERVATIONS
71
64
5
500
86
35
49
105
PREANALYSIS
TREATMENT 2
A/F
U/F
A/F
U/F
U/F
U/F
A/F
U/F
LOCATION OF DATA
IN REPORT
Appendix 1
Appendix 1
Not tabulated
Mot tabulated
Figure 9
Appendix 4
Appendix 3
AREA COVERED
Primary study area
Primary study area
United States
Atlantic and Gulf Coast Plain
Florida, excluding study
areas, (see Figure 8)
Supplementary study area
in Sarasota County
Primary study area
1.   Radium-226 dissolved in water
2.   U = unpreserved,  A = acidified,  F  = filtered
3.   Desoto, Hillsborough, Hardee, Manatee and
    Polk Counties (shown in Figure 1)

-------
relative to the study area to allow use in the statistical analysis.   In other
instances, gross alpha or stable chemical data from previous studies were
utilized.  These are not included in Table 2.

     The FWPCA data were originally developed by Shearer et al.  (1966) as part
of a 1966 survey by the Technical Advisory and Investigations Branch,  Cincinnati,
Ohio.  Radium-226, radon-222, natural  uranium, thorium-230, polonium-210,
gross alpha, and gross beta were determined together with gross  chemical
analyses on 105 public and private water supply wells in central Florida.  EPA
data (category 1 above) were collected from 1973 to 1976 by the  Office of
Radiation Programs, in cooperation with county and state health  departments,
and analyzed by the Office of Radiation Programs, Eastern Environmental
Radiation Facility, Montgomery,  Alabama.   Also included in Appendix 1 are
selected USGS data from a 1974 to 1976 survey by Irwin and Hutchinson  (1976).
Open file U.S. Geological Survey data  from Florida were collected in the
course of a nationwide assessment of radium in ground water by Scott and
Barker (1962).  These data were  provided  by R. Scott (private consultant,
Atascadero, California).

     The locations of wells sampled  by the USEPA, the USGS,  and  FWPCA in Polk,
Hillsborough, Hardee,  Manatee, and Sarasota Counties are shown in Figures 6,
7, and 13.
                                     36

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       R21E
                     R22E
                                      R23E
                                                      R24E
                                                                      R25E
                                                                                     R 26 E
                                                                                                     R 27 E
                                                                                                                     R 28 E
                                                                                                   P-12.
                                                                                                 V	X HAINES CITY
                                    P-13    LAKELAND
                                                                   P-49,P-50,P-51,P-52
                                                          754-151-45 I^BARTOW
                                                          P 47. f  \   P-52A
                                                             '"  \P-.55.        .p.57
                                                             P-61  .',A'P-59'P"58P-57A
                                                              P-60  .\752-150-l
                                                              P-62 '
                                                                        P-81 FORTMEADE
                                                       P-74.    p-84-  PiBZ-)''p-79
                                                                                .p.84(.
                                          P-87, P-88   p-86
                                           P-85A-
   HB-ll.HB-12
      .  HILLSBOROUGH CO.
           MANATEE CO
                                              POLK CO.   .P-88F
OBOWLING GREEN
            H-B
      FOR LOCATIONS OF WELLS
            SEE FIGURE 7.
        BOUNDARY OF MINERALIZED AREA;
        HACHURES ON MINERALIZED SIDE
                   OGIC CROSS
        SECTION SHOWN IN FIG.3
        WELL IDENTIFICATION NUMBER
            STEWAHT(1966| OR WILSON
        LOCATION OF WELL EP-53-15
                 (SEE APPENDIX 1)
                                                                 DS-l 15 MILES SOUTH .
     R21E
                     R22E
                                                                                                                     R28E
Figure  6.    Location of  wells  sampled  in  Polk,  Hillsborough,  and  Hardee  Counties
                                                             37

-------
(A
m
CO
V)
t
 (A
 in
 ro
 l-
 (A
 O
 CO
        R 19E

            M-
                             R20E
                                 JL.
                                         R21 E
                          MANATEE  COUNTY
                                                                      R22E
                                                                        M-4*
                                                                 M-3A.
     OPARRISH

         M-2a
                                              >M-3
                                                          M-5'
                                                                      M-9a-M-10
                                                                                M-11
                                           M-8
             01234

              SCALE:MILES
                   LEGEND
\
          A'
M-10
BOUNDARY OF MINERALIZED AREA;

HACHURES ON MINERALIZED SIDE


TRACE OF GEOLOGIC CROSS

SECTION SHOWN IN FIG. 2.


GROSS ALPHA <2.0 pCi/l


LOCATION OF WELL GM10A-1

          (SEE APPENDIX 1)
                                                                             oo
                                                                             *
                                                                             (A
                                                                        M-15a
                                                    8QMYAKKA CITY
                                                     .A
                                                   FLORIDA
                                                 GEOLOGICAL
                                                 SURVEY WELL
                                                     W-2595
                                                                           M-18(
                                                                             00
                                                                             Ul
                                                                             (A
            CO
            0)
            CA
         R19E
                     R20E
                                     R21 E
R22E
               Figure 7.   Location of  wells  sampled  in Manatee County.
                                          38

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               TECHNIQUES FOR MONITORING RADIUM-226 IN GROUND WATER

MONITORING OBJECTIVES

     Two commonly recognized objectives for monitoring radium-226 in ground
water include public health investigations, (i.e.,the radium content relative
to established drinking water standards), and environmental quality studies to
ascertain ambient quality or changes therein, typically as a result of human
activities.  Both objectives are quite necessary but unfortunately data
collected for one purpose can be rather inadequate with respect to the other.
Ideally, both needs should be served.  Some of the findings and difficulties
encountered using available data in the present study may help improve future
investigations and for this reason are elaborated upon.

SAMPLING POINTS AND METHODS FOR SAMPLING RADIUM-226 IN GROUND WATER

     By far most radium-226 analyses of ground water collected in Florida up
to the present time are based on one-time grab samples collected at a well
head or spring orifice, or they are raw or finished water samples from a water
supply system, most of which are supplied by a number of wells pumping into a
common reservoir.  Both sampling objectives cited in the previous paragraph
utilize these various sampling points.  Obviously, health-related studies are
essentially restricted to wells and springs used for potable supply whereas
ground-water monitoring studies will include and may solely use wells installed
or at least utilized for monitoring purposes.  Ultimately, trends in potable
status would also be of concern.  Certain characteristics of these sampling
points, sampling methods, or physical attributes of the water sample, per se,
necessarily interrelate to the objectives of a given study and the potential
for reaching definitive conclusion.

     Samples collected from public or domestic water supply wells in the study
area are, with rare exception, equipped with pumps and the wells are actively
                                        39

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used.   Suspended solids are typically quite low and the water samples are
likely to be representative of the aquifer(s) tapped.   Because such wells are
commonly completed with relatively large intervals or production zones, the
water sample is a composite of quality in this interval.  Wells used solely
for monitoring, particularly shallow ones are generally not equipped with
pumps and sampling is done with a bailer or thief sampler.  If a pump is
present, it is used intermittently for sampling purposes only.  As a result,
water quality in the borehole may not be representative of the aquifer(s) and
suspended solids are likely to be higher than a well  in daily use.  Wells used
solely for monitoring are used intermittently, typically are not equipped with
pumps, and are completed with less care than supply wells.  As a result they
produce more settleable and suspended solids.  Introduction of a bailer or
thief sampler or startup of a pump in a dormant well  can easily raise the
level  of suspended or settleable solids to concentrations not commonly found
and certainly not acceptable in a potable supply well.   Proper sampling of
such wells and subsequent sample handling can markedly  influence the analytical
results and more importantly, the importance of the data relative to the study
objectives.

SAMPLE PRESERVATION AND HANDLING

     Water samples to be analyzed for radium-226 are usually either acidified
and filtered before analysis or they are simply filtered.  Marked differences
in analytical results using the two methods commonly occur, due in large part
to the amount and composition of settleable and suspended solids in the
sample.  Acidification immediately after sampling is  favored in health-related
surveys because it is reasoned that the water sampled is representative of the
potable supply and that acidification to pH of about two duplicates conditions
in the stomach.  Another reason for acidification is  to prevent sorption of
radium onto the walls of the sampling container.

     Samples collected for hydrologic investigations  or as part of surveys to
ascertain ambient and contaminated levels of radium in  ground water are
filtered as soon as possible after collection and preferably in the field.
Dissolved radium is defined as that passing through the filter.  Acidification
to prevent plating out is optional.  The USGS does not  favor acidification for
                                   40

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naturally occurring  isotopes  in  the  uranium  and  thorium  decay  series  and
believes that  other  factors such  as  Eh  and oxidation  state may be  more  signifi-
cant, particularly for fission products  (Thatcher  et  al., 1977).   Dissolved
radium may be  markedly lower  with  this  approach  of filtering first and  then
acidifying as  compared to acidification  first, followed  by mixing,  digestion,
and filtering.  For  example,  in five of  the  six  data  pairs shown in Table 4,
the USEPA data means range from  1.06 to  2.88  (mean 2.04) times  higher than
USGS data.  The significance  of this difference'  is weakened by  the fact that
the samples are not  from the  same  wells.  However, splits of three surface
water and two  ground-water samples collected  by  Irwin and Hutchinson  (1976),
were analyzed  for radium-226  first using filtered  raw water and then  acidified
raw water (followed  by filtering)  with  the following  results:
                                           Dissolved  Radium-226, pCi/1
Sample         Station               Untreated Samples (1)  Acidified Samp1es(2)
1.  Lithia Springs near Lithia           0.68   .07         0.80   .08
2.  Alafia River at  Lithia               0.06   .012         0.53   .05
3.  Peace River near Fort Meade          0.12   .024         0.58   .006
4.  Well - Upper Floridan                0.24   .048        20.00  1.4
5.  Well - Lower Floridan                0.06   .012         0.14   .028
           Mean for  five samples         0.23                4.41   ratio = 0.052
           Mean for  four samples         0.23                0.51   ratio = 0.45
Two sigma error terms shown include  counting  and analytical  error; estimated as
follows:
<.5 pCi/1 : 20%; 0.5 to 2 pCi/1  :  10%;  2 to  10 pCi/1  : 7% (L. Schroder, USGS,
personal communication, April 11,  1977).  Ratio =  untreated r acidified.

     They concluded  that little difference was attributed to sample prepara-
tion but rather to the presence of particulate material  which was  thought to
be high in Sample 4.  From the comparisons presented by  Irwin and  Hutchinson,
we conclude that dissolved radium-226 in acidified samples is  1.17 to 83 times
higher than in untreated samples, and particulate  material  can greatly increase
dissolved radium when acid preservative  is used.    The mean radium-226 content
of the acidified USEPA samples is 2.85 pCi/1  versus 1.84 pCi/1  in filtered but
unacidified samples in the Geological Survey data  base (data contained in
Appendix 1).    If plating out occurs, samples with  no appreciable suspended
solids may show a lesser concentration of dissolved radium when the acidification
                                   41

-------
step is omitted.   However, this plating out hypothesis is not well supported
in the literature.   It is apparent then that analytical  differences do exist
as a function of sediment content and sample preservation.   Although differences
are unidirectional, they are rather variable and not subject to simple correc-
tion.

SIGNIFICANCE RELATIVE TO FUTURE STUDIES

     The authors conclude that the available radium-226  data base for central
Florida ground water is fragmented because of the different objectives and
sampling/analytical methods incorporated in past studies.  Future sampling
efforts focused clearly on ascertaining public health significance of radium
in ground water seem bound to utilize sampling methods involving acidification
followed by filtration.  Application of this method, in  conjunction with
sampling of monitoring wells using bailers, thief samplers, or very inter-
mittent pumping is likely to generate spurious data for  evaluating environ-
mental levels of dissolved radium-226.   Acidification of turbid water samples
from public or private potable water systems is also likely to produce higher
concentrations of dissolved radium than if the water is  filtered before
acidification.  Techniques involving acidification in the field, followed by
filtration in the laboratory, should be reserved for health-related surveys of
water systems that are in use.  In terms of settleable or suspended solids,
samples must be representative of the water being consumed.  Mere collection
of samples, with little regard as to the amount and composition of suspended
solids, combined with acidification prior to filtering,  may produce analytical
results with little technical value for public health or environmental monitor-
ing purposes.

     Monitoring studies to determine ambient conditions, temporal, or spatial
trends, contaminant migration, or equilibria between dissolved and suspended
fractions and between these and host strata with respect to radium require
different sample handling procedures.  Actual sampling points, be they wells
or springs, can be either representative of a small vertical interval or
volume of the subsurface or they can be points that are  expressive of some
average condition within an aquifer or an aquifer system.  Depending on the
objectives for a given study, one or both types of sampling points are of
                                   42

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value.  With respect to filtration and acidification, samples should be
filtered in the field, if at all possible, or at least upon arrival at the
laboratory.  Filter papers should be saved for analysis of the activity in the
solids.  Acidification after filtering is recommended to prevent or reduce
plating out.

     Studies or at least data collection concerning radium in ground water of
central Florida will continue.   Misapplication of study objectives to the
types of sampling points available, e.g., public health study objectives and
sample handling applied to monitoring and connector wells, should be studiously
avoided by regulatory agencies  and industry alike.   There is genuine need to
study both environmental quality and public health  in a multiple-aquifer,
multiple land use setting.  Cost effective and information-effective data
collection programs are essential lest the next 30  years of mining activity
and related monitoring simply mirror the past shortcomings.
                                   43

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                     RADIUM IN SURFACE AND GROUND WATER

     Although it is beyond the scope of this report to give a detailed assess-
ment of radium occurence in surface and ground water throughout the world and
United States, a short discussion is included to put the observations in
Florida and in the specific study area of this report into better perspective.
It should be noted that some of the values refer to a composite of all radium
isotopes whereas in the detailed part of this study only radium-226 is
addressed.  However, radium-226 is the most common isotope and is therefore
believed to be a fair approximation of total radium.   There are some important
exceptions to this generalization and these will be noted in a later section.
Table 3 is provided to summarize the text that follows.

CONCENTRATIONS IN CONTINENTAL AND OCEANIC WATERS

     Radium concentrations in ocean and surface waters tend to be quite low.
Koczy (1958) observed that near bottom water varied from 0.08 pCi/1 in the
Indian Ocean to 0.51 pCi/1 in the Pacific Ocean, with surface ocean water at
about 10~  pCi/1.  Tokarev and Shcherbakov (1956) considered 0.1  pCi/1 as the
mean for ocean water, compared to  0.1  pCi/1  in  fresh  water  lakes,  and  0.2 pCi/1
in rivers.  Miyake et al.  (1964) observed 0.08 pCi/1  dissolved radium in
Japanese rivers.   Hursh's  (1953) tabulation of 42 radium-226 observations made
in water supply systems dominated by surface water as a  source showed a
geometric mean (GM) of 0.04 pCi/1.  We conclude that surface water values for
radium-226 are less than 0.1 pCi/1.

     Ground water is generally higher in radium.  Water  supply systems in
which excessive radium is  present are typically ground-water dominated
(Samuels, 1964).   With respect to hydrogeologic factors  and their influence on
radium in ground water, Tokarev and Shcherbakov (1956) distinguished between
sedimentary and siliceous  igneous rocks and between circulating and stagnant
aquifer systems.   In sedimentary rocks, mean radium concentration in a cir-
culating system is 2 pCi/1 as opposed to 300 pCi/1  in a  stagnant system.
Where siliceous igneous rocks are predominant, radium varies from 2 pCi/1 in
a circulating system to 4  pCi/1 in a stagnant one.
                                      44

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       TABLE 3.  SUMMARY OF THE OCCURENCE OF DISSOLVED RADIUM IN WATER
        MEDIUM
WATER
  Ocean
    Bottom
    Surface
    Mean

FRESH WATER LAKES

RIVERS
  Japan

POTABLE WATER SUPPLY

  Surface Water

GROUND WATER
  Sedimentary Rocks

    Circulating Water
    Stagnant Water
  Igneous Siliceous Rocks
    Circulating Water
    Stagnant Water

UNITED STATES

  Conterminous
  Atlantic and Gulf
    Coastal Plain
  Florida - Exclusive of
   central P04 District

  Central Florida
CONCENTRATION (pCi/1)
        0.07*
   0.08 - 0.15
        .0001
       0.1*

       1.0*

       0.2*
       0.08
       0.04**
       2.0***

     300***


       2

       4



   0.1  - 720

       0.15**
       0.2**


   0.2 -  12
       1.0
   1.0 -  15**
         REFERENCE
Koczy, 1958
Koczy, 1958
Tokarev and Shcherbakov, 1956

Tokarev and Shcherbakov, 1956

Tokarev and Shcherbakov, 1956
Miyake et al., 1964
Hursh, 1953


Tokarev and Shcherbakov, 1956
Tokarev and Shcherbakov, 1956
Tokarev and Shcherbakov, 1956


Tokarev and Shcherbakov, 1956
Tokarev and Shcherbakov, 1956


Scott and Barker,  1962
Present study;  calculated
from Scott and  Barker, 1962


Scott and Barker,  1962
Scott and Barker,  1962


Present study
*      Estimated mean
**     Geometric mean
***    Arthmetic mean
                                    45

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     Scott and Barker (1962) observed that radium in ground water in the
conterminous United States ranged from less than 0.1 pCi/1 to 720 pCi/1.
Subdividing the United States into ten regions based on similarity of geologic
physiographic, and ground-water conditions, they found that the geometric mean
of six regions (Atlantic and Gulf Coastal  Plain, Appalachian Orogenic Belt,
Eastern Stable Region, Western Stable Region, Rocky Mountain Orogenic Belt,
and Pacific Orogenic Belt) with adequate data varied from <0.1 pCi/1 to
0.6 pCi/1.  A log-normal probability plot of over 500 observations of radium
data for ground water throughout the country reveals a geometric mean concen-
tration of 0.15 pCi/1.  The Atlantic and Gulf Coastal Plain Region (Plate I,
Scott and Barker, 1962), which includes Florida, has a geometric mean of
0.2 pCi/1 of radium.  In general, ground-water values as determined for the
United States have a geometric mean of about an order of magnitude larger than
concentrations in surface waters.

FLORIDA GROUND WATER

     Radium-226 data from areas outside the central Florida land pebble
district were observed in 35 locations in 12 counties throughout the state
(Figure 8).  The plotted data are from Irwin and Hutchinson (1976) and open
file data of the U.S. Geological Survey (Figure 9).  The latter data, largely
developed in the course of the Scott and Barker (1962) study, were supplied by
R. C. Scott (Atascadero, California, written communication).  Most of the
Florida data reported by Scott and Barker are from flowing wells and are
therefore not likely to be affected by wastewater or other surface sources of
contamination.  No attempt was made to separate the data according to aquifer
or aquifer system.   It is assumed that the radium present is from natural
causes.  No correlation of radium, with chloride, floride, uranium, or well
depth is apparent.

     The geometric mean radium concentration for background dissolved radium
in Florida ground water is 1 pCi/1, with essentially all values falling in the
range of 0.2 to 12 pCi/1.  A near linear fit of the data on a log-normal
probability plot suggests that the observations are part of the same popula-
tion.

                                      46

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        COUNTIES IN WHICH GROUND WATER SAMPLES
         ANALYZED FOR RADIUM-226 ARE LOCATED
        NUMBER OF RADIUM-226 OBSERVATIONS LOCATED
         IN INDICATED COUNTY
        OUTLINE OF PRIMARY STUDY AREA
        OUTLINE OF SUPPLEMENTARY STUDY AREA
Figure  8.   Location of  counties used  to establish  background levels  of
            radium-226  in Florida ground water.
                                       47

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  100-
    50-
    20
o
a
 X
tO
   10-
    6.0
cc
Q
(A

Q
    2.0
   1.0-
     .5
     .2
GEOMETRIC MEAN= 1 pCi/l


GEOMETRIC

STANDARD DEVIATION = 4.4
     2%     5    10  15 20    30  40  50  60  70   80 85  90    95   98%

                                  PERCENTAGE


        Figure 9.  Log-probability plot of background levels of radium-226

                   in  Florida ground water.

                                    48

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     Assuming these data are reasonably representative of the radium-226 in
Florida ground water exclusive of the central  Florida land pebble phosphate
district study area, the geometric mean is about one pCi/1 or about an order
of magnitude higher than the national geometric mean of 0.15 pCi/1, calculated
from radium data presented by Scott and Barker (1962).  Arithmetic and geo-
metric means for radium in ground water for the study area in central Florida
are higher yet, with averages typically ranging from 1.5 to 15 pCi/1.  Since
portions of Florida contain economic deposits  of monazite sands which are
enriched in thorium, radium-228 may also be elevated in associated ground
water.  Unfortunately, no radium-228 data are  available for Florida ground
water.  In summary, there is good evidence that Florida ground water has
naturally higher radium-226 levels than either the nation as a whole or the
Atlantic and Gulf Coastal Plain region.  With  this introduction established,
we will now focus on radium in ground water of central Florida.
                                        49

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  WATER QUALITY EFFECTS OF PHOSPHATE MINERALIZATION AND THE PHOSPHATE INDUSTRY
     As previously mentioned,  data bases developed by FWPCA, USERA, and USGS
are available.   Because of differences in analytical  procedures, or time of
sampling, the data bases were treated separately to analyze for spatial and
temporal changes in ground-water quality.  With respect to spatial variation,
data availability as determined by aquifer and mineralization or mining
status resulted in decidedly uneven coverage in certain categories.  In order
to make fullest use of the available data for 1973-1976 and also maintain
analytical comparability, the data group with maximum observations, either
USEPA or USGS,  was selected for any given comparison of water quality according
to aquifer, mining/nonmining, and mineralization criteria.

     Three separate aquifers (water table, Upper Floridan, Lower Floridan)
were considered for three separate land status categories (mined, unmined, and
nonmineralized).  Aquifer information was obtained by comparing well depth and
casing  information relative to hydrogeologic conditions, and from information
presented in Irwin and Hutchinson (1976).  Land use information was obtained
from existing topographic maps, geologic reports, and mineral leasing records
(W. Lancaster,  Texas Instruments, Inc., written communication, April 1, 1977;
Wayne Thomas, Inc., 1976).  Aquifer and land use information for each sample
is presented in Appendix 1.

STATISTICAL METHODOLOGY

     Basic approaches taken to analyze the data include characterization of
distributions,  central tendency (mean, geometric mean), and variance (geometric
standard deviation, standard deviation).  With this information, nonparametric
tests were selected to compare observations for significant difference as a
function of time  (1966 versus 19/4-1976), space (mineralized, nonmineralized,
etc.  ), and depth  (aquifer).  Primarily because of the  limited number of
observations and  therefore uncertainty concerning population distribution,
nonparametric methods were used to analyze and compare  variance and central
tendency.
   Mineralized areas are defined as those within the pebble area (i.e., 55
   percent or more BPL) of phosphate mineralization as mapped by Mansfield
   (1942, Plate 5).  Locations of mined areas and plant sites appear on a
   detailed map by Wayne Thomas, Inc. (1976).  Wells located in such areas
   or within one mile or less thereof are classified in the "mined" category.
                                     50

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     Statistical  analysis techniques often assume that the population or
grouping of observations has a distribution which is known.  If data are
highly skewed with numerous small  observations and several large ones, it may
have a log-normal distribution (Koch and Link, 1970), i.e., the logarithms of
the observations  have a normal distribution.  Trace elements, for example, are
log-normally distributed (Ahrens,  1957) as are many types of environmental
data (Denham and  Waite, 1975).  Therefore, it would be reasonable to expect
trace amounts of  radium-226 in ground water to be approximated by the log-
normal distribution and a plot of such data is expected to have a
linear appearance on log probability paper.  The geometric mean equals the
50th cumulative percentile line, and the geometric standard deviation is
defined by the line slope.  At a geometric standard deviation of about 1.3 or
less, skewness is sufficiently small that the population might be treated as
normal without transforming the logarithms.  Failure of a set of observations
to approximate a  log-normal distribution can be inferred using the Kolmogorov-
Smirnov goodness-of-fit test.  Denham and Waite (1975) suggest that when the
plotted data have a linear trend,  a single and presumably  background popula-
tion is depicted.  Several line segments on a single log-normal probability
plot suggest several overlapping populations, the distribution of which is
unknown when few observations define a given line segment.

     Log-normal probability plots  of radium-226 data were extensively used to
characterize several data sets in  terms of geometric mean and geometric stan-
dard deviation for each aquifer or land category.  In order to test possible
relationships between the various  groups of data which generally were not from
a single, clearly defined distribution, "distribution-free" techniques of
hypothesis testing were used.  Two nonparametric statistical  tests were used,
the Mann-Whitney U test and the Kruskal-Wallis one-way analysis of variance
(by ranks) test.   The Mann-Whitney U test is a nonparametric analog of the
student t test and can be used to determine if two independent groups were
selected from the same population.  A variant of the Mann-Whitney test (Springer,
1976) is used to validate a basic assumption of the test, i.e., whether both
data sets are similarly dispersed.  The Kruskal-Wallis test is a nonparametric
analog to the parametric one-way analysis of variance or F test used to test
dependency between three or more independent samples.  A logical extension of

                                       51

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the Kruskal-Wallis test, particularly when the ruling hypothesis is rejected,
is to determine which groups are significantly different from one another.
Gibbons (1976) suggests that simultaneous multiple comparisons is the best
method for this, particularly as described in Dunn (1964).  Since several
simultaneous statements of difference are made, the level of significance used
is larger so that a single difference is more likely to be detected.  It is
also quite possible that several groups may not be equal as indicated by the
Kruskal-Wallis test but that simultaneous multiple comparisons may not find
any pair with significant differences.  Siege! 0956) and Gibbons (1976) give
excellent examples and explanations on nonparametric statistics and should be
consulted by those interested in exploring further into this subject.

SPATIAL VARIATIONS IN WATER QUALITY

     Table 4 summarizes the number of observations by source (USEPA, USGS),
range, mean, and standard deviation for the land categories and aquifers
considered.  The USGS data were used to analyze the water table aquifer and
Upper Floridan aquifer and USEPA data were used for the Lower Floridan
aquifer.  Temporal changes in water quality are discussed in a subsequent
section.

Water Table Aquifer

     Unfortunately, radium-226 data for the water table aquifer is restricted to
mineralized areas with no information available in the nonmineralized portions
of the study area (Table 4).  For 23 observations in the mineralized unmined
area the geometric mean (GM) is 0.17 pCi/1 and the geometric standard deviation
12.9.  The observations show pronounced linearity on log probability paper
(Figure 10), suggesting a log-normal population.   This, however, was rejected
by the Kolmogorov-Smirnov goodness-of-fit test at the 95 percent confidence
level.  Three of the 23 observations exceed the 5 pCi/1 combined radium-226
and radium-228 standard for community water systems (U.S. Environmental
Protection Agency, 1976a).
                                     52

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                 TABLE 4.  SUMMARY OF AVAILABLE RADIUM-226 DATA AND STATISTICS
                                                             AQUIFER
          1973-1976 EPA DATA
                     \	
en
CO
       1974-1976 USGS DATA
                     DATA SET
             USED IN ANALYSIS
                                                                          LOWER FLORIDAN
                                                                                               COMBINED
                                                                                                EPA DATA

-------
  100-
    50-
    20
   10-
o
a
to
3   5.0
D
O
   2.0

O
(0
   1.0-
     .5
                    WELLS LOCATED IN UNMINED AREAS (*
       WELLS LOCATED IN MINED AREAS 
                          ./    *     V
     2%     5    10  15 20   30  40  50  60  70   80  85 90   95    98%
                                 PERCENTAGE

     Figure 10.   Log-probability plots of  USGS data for  the water table
                 aquifer in  unmined and mined mineralized areas.
                                    54

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     For 12 observations in the mined mineralized area, the GM is 0.55 and GSD
is 3.3, indicating a population which is much less skewed than in the mineral-
ized unmined area (Figure 10) but is similar in having a strong linear trend.
That radium in mined, mineralized areas is log-normally distributed can not be
rejected by the Kolomogorov-Smirnov goodness-of-fit test at the 95 percent
confidence level.  None of the observations exceed 5 pCi/1  for radium-226.  No
radium-228 data are available to confirm whether combined radium-226 plus -228
exceeds the 5 pCi/1 limit established by USEPA for public water supplies.

     In order to determine whether these two data sets are in fact from the
same population, a "distribution-free" method of comparison was used.  For
testing whether two groups are equally likely to have been taken from the same
population, the nonparametric Mann-Whitney U test is quite effective (Siege!,
1956).  Using a method described by Springer (1976), the observations in both
data sets were first tested for similar dispersion, a prerequisite assumption
for use of the Mann-Whitney test.  Dispersions or variances are similar at the
95 percent confidence level.  The test value or "Z" statistic generated by the
Mann-Whitney test was 1.01.  This value is too small to reject the null
(ruling) hypothesis at the 95 percent confidence level.  Therefore, the two
samples appear to have been taken from the same population.  Based on these
data and the analysis described, no impact on the water table aquifer appears
to have occurred as a result of mining.

Upper Floridan Aquifer

     As the USGS data base has observations in all three land classification
groups, it was selected to characterize radium-226 in the Upper Floridan
aquifer.  All groups had 10 or less observations and no attempt was made to
plot on log probability paper.  Statistical parameters used to express central
tendency and standard deviation are arithmetic (Table 4).  In areas of miner-
alization without mining, one out of the five observations is greater than
5 pCi/1.   In areas subject to the impact of mining, one out of ten observa-
tions  is greater than 5 pCi/1.  Of the three observations  in the mineralized
                                        55

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area, two are greater than 5 pCi/1.  To test whether these three groups are
part of the same population, the Kruskal-Wallis one-way analysis of variance
test was used, yielding a test value for H of 52.37 .   The probability of H
this large due to random chance is less than 0.001, inferring that the three
groups are not equal.  Using simultaneous multiple comparisons, at the 80
percent confidence level, only the mined versus nonmineralized groups are
significantly different whereas for the nonmineralized area, mean radium-226
is greater than that in mined areas.  Based on these data and analysis, no
impact on the Upper Floridan aquifer seems to have occurred as a result of
mining and related waste management.

Lower Floridan Aquifer

     The USEPA data base was used to characterize the  radium-226 in the Lower
Floridan aquifer.  Two groups, mineralized unmined and unmineralized, have the
greatest number of observations, 24 and 14 (Table 3).   A log-normal probability
plot of dissolved radium-226 in the mineralized unmined area exhibit three
distinct line segments.  This pattern remains if the six observations from the
mined area are included (Figure 11).  They were included because they are
evenly distributed within the range of values for the  mineralized unmined
area.  A very similar alignment of line segments also  characterizes the Lower
Floridan in areas of nonmineralization (Figure 11).  This suggests that radium
in the Lower Floridan aquifer is not related to phosphate mineralization.

     Although only 4 of the 24 observations in the unmined, mineralized areas
exceed 5 pCi/1 for radium-226, other samples with lesser concentrations might
also exceed the USEPA standard of 5 pCi/1 radium-226 plus radium-228.  In the
mined area none of the six samples contained over 5 pCi/1 radium-226 whereas
in the nonmineralized area, one well of 14 sampled exceeded 5 pCi/1.  Again,
radium-228 data are unavailable.  On the basis of available radium-226 data,
phosphate mining and processing do not appear to have  deteriorated the quality
of water in the Lower Floridan.
     The visual similarity in the plots for data from mineralized and non-
mineralized areas is inferred by the Mann-Whitney U test, which has a test "Z"
value of 0.08.  This has an associated probability of 0.47, clearly much
                                        56

-------
  100
    50n
    20
   10-
o
a
to
5
D
O
<
DC
Q
O
W
    2.0
   1.0-
    .5-
     .2
   WELLS LOCATED IN MINERALIZED AREAS ()
             (MINED & UNMINED)
                                          WELLS LOCATED IN
                                           NONMINERALIZED AREAS (*|
2%      5

  Figure 11
10  15 20   30   40  50  60  70   80  85 90   95
                PERCENTAGE
                                                                       98%
                  Log-probability plot of USEPA data for the Lower  Floridan
                  aquifer in mined and unmined mineral ized areas  and  in
                  nonmineralized  areas.
                                    57

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greater than the pre-set alpha of 0.05.   Therefore, the ruling hypothesis is
accepted, i.e., there is no significant  difference in radium content of ground
water in mineralized versus nonmineralized areas.

     Plots of dissolved radium-226 data  for the Lower Floridan aquifer suggest
the presence of three separate populations.  Grouping all the radium-226 into
a single log probability plot and using  graphical techniques described by
Sinclair (1974), the curve was partitioned into three parent populations as
shown in Figure 12.  The three populations were combined in proportion to
their presence to generate the observed  plot.   Population B is dominant.  It
represents 52 percent of the total observations and has a GM of about 3 pCi/1.
About 10 percent of population B observations  are suggested to exceed the 5
pCi/1 limit.  Population A is second most abundant, contributing 37 percent of
the observed radium-226 values.   With a  GM of  about 0.7 pCi/1 , this population
will have on the order of one percent of its observations exceeding the 5
pCi/1 limit.  Population C, representing about 11 percent of the total observa-
tions, has a GM of 10 pCi/1 and has about ninety percent of its values above
the 5 pCi/1 level.  All of population C  observations were taken outside the
areas defined to be influenced by mining.

     Clearly the Lower Floridan aquifer  is a complex system with radium-226
distribution dependent on several processes and/or sources.  Much more detailed
information on water chemistry, lithologic composition, and hydrology would be
required in order to attempt to define the underlying reason for these sug-
gested populations.  Modification in the chemical and physical processes in
the Lower Floridan aquifer so as to enhance the content of dissolved radium to
the level typified by population C would be highly undesirable.  We conclude
there are occasional high radium-226 observations in ground water from the
Lower Floridan aquifer associated with natural factors essentially unrelated
to phosphate mineralization or the central Florida phosphate industry.

     Elevated levels of radium-226 in the Lower Floridan aquifer can be due to
a number of natural factors unrelated to phosphate mineralization or waste
management in the phosphate industry.  Increased solubility of radium occurs
in ground water enriched in chloride (Tanner,  1964).  Kaufman and Dion  (1967)
have shown that upwelling of mineralized water occurs along the trace of the
                                    58

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  100-
    50
    20
    10-
                        Population (C)
o
a.
 i>

-------
southern Peace River.   Widespread, pronounced reduction of the potentiometric
surface for the Lower Floridan aquifer is well documented and problems of
water supply and water quality are receiving increasing attention in central
Florida.  Sea water encroachment and upwelling of deeper more mineralized
ground water in cones of depression due to pumping from the Lower Floridan
aquifer, particularly the Avon Park Limestone, are of particular concern.
Whether heavy pumping of the Floridan aquifer will actually induce upward
movement of more saline, possibly radium-enriched water is an unanswered
question and probably one which will require much additional data and in-
terpretation.

     Dissolved gross alpha radioactivity values for 10 wells in Manatee County,
9 of which are for domestic use, are less than 2 pCi/1 in all  cases (See
Figure 7).  The wells tap the Floridan aquifer which is undifferentiated as to
Lower and Upper because of the absence of a prominent aquitard at the base of
the Tampa Formation in this area (Wilson, 1975).  Because the correlation
between dissolved radium and gross alpha is rather inconsistent, particularly
at low concentrations and because dissolved radon accounts for most of the
alpha activity, the Southwest Florida Water Management District has gradually
increased the gross alpha threshold from 2 to 5 pCi/1 and then from 5 to 15
pCi/1 as the basis for requiring analysis for radium-226 (B. Boatwright,
SWFWMD, personal communication, May 31, 1977).  That is, below 15 pCi/1 gross
alpha, radium is believed to be present in acceptable levels of 5 pCi/1 or
less.  For this reason, values of 2 pCi/1 gross alpha in the Manatee County
wells for which only gross alpha data are reported on herein,  are believed to
contain very low concentrations of radium-226.

     Mean radium content in seven Manatee County wells tapping the Floridan
aquifer was 4.52 pCi/1 versus 1.23 pCi/1 from three water table wells.  Radium
varied from 0.11 to 3.7 (mean 1.94) in six wells of unknown depth or produc-
tion interval.  In general, radium increases with depth.  There was no phosphate
mining at the time of sampling; hence, this source is discounted and natural
factors other than the phosphate industry are believed responsible for high
radium values observed.  This is reinforced by the fact that half of the wells
with values exceeding 3 pCi/1 are located in areas not considered ore bearing.
                                    60

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     In summary, the statistical analysis techniques utilizing available data
and the conclusions therefrom are probabilistic in nature.  There is neither
"proof", per se, for the conclusions herein nor can they be considered final.
Qualification of the available data is a necessary procedure designed to put
the interpretations into proper context but without necessarily discrediting
the conclusions.  The exact extent to which phosphate mineralization causes
elevated radium-226 in the three aquifers considered is not readily discern-
ible.  This is due in part to lack of observations in the water table in
nonmineralized areas and the availability of only three observations for the
Upper Floridan aquifer for the same areas.  Theoretically, phosphate minerali-
zation should be a radium-226 source for the Upper Floridan aquifer due to the
intimate association of aquifer and ore body.  However, there are too few data
to make meaningful comparisons on the basis of land use or mineralization.

     Under natural conditions the water table aquifer is perhaps not as
closely associated with phosphate mineralization as is the Upper Floridan.
However, disturbance by phosphate mining directly disrupts the water table
aquifer.  Overburden and wastes associated with benefaction and chemical
processing have the potential for introducing radium into both aquifers.  Yet,
radium-226 data suggest that mining has not appreciably changed radium-226
levels in the water table.  Again, this conclusion is probabilistic, being
based on statistical analysis of available data.  To presume no change is
occurring may well be erroneous.  Ground-water dynamics are greatly affected
by mining, as is the lithological sequence, the matrix and leach zone portions
of which have a potential for contributing radium-226 to ground water.   It is
difficult to believe that change is not underway.

     On the basis of the data presented herein, radium-226 in the Lower
Floridan aquifer appears to bear no relation to the effects of land use or the
presence/absence of phosphate mineralization.  The distribution pattern of
radium data on log-probability plots suggests a complex system and possibly
multiple populations,  probably stimulated by natural factors unrelated to
phosphate deposits or the industry.   In general, radium-226 levels below
mineralized areas are low.  Possibly radium-226 is depleted as a result of
                                       61

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mineralized areas are low.   Possibly radium-226 is depleted as a result of
dilution and sorption in overlying strata and aquifers.  Although the data are
limited and numerous exceptions are present, radium-226 generally increases
with salinity which, in turn, varies with well depth and position in the flow
regime within the Floridan aquifer system.  Radium-226 concentrations of 10-20
pCi/1 may be associated with more mineralized or brackish ground water in the
deeper parts of the aquifer.  Whether altered flow patterns are present due to
pumping and whether such patterns can induce upwelling of water with higher
radium content are unanswered questions.

     The existing radium-226 data base is marginal in terms of number and
spatial distribution of analyses, particularly for the water table and Upper
Floridan aquifers.  Aquifer system complexity and widespread changes in land
use  require a greatly increased sampling program if these variable are to be
considered.  Inconsistency in study objectives and analytical procedures and
lack of overlap between the USGS and USEPA data bases on a well-by-well basis,
or even by aquifer, restrict reaching precise definition of spatial changes in
radium-226 content of ground water.
                               SARASOTA COUNTY

     Because of its location at the extreme southern end of the Central
 Floridan  phosphate district and closeness to the discharge portion of regional
 ground-water flow within the Floridan aquifer system, Sarasota County radium-
 226  data  are considered separately.  Radium-226 data for untreated water from
 public  and  private wells are shown in Appendix 4.  Locations are shown on
 Figure  13.  Most wells are completed in both the water table aquifer and Flori-
 dan  aquifers.  Clear distinction between Upper and Lower Floridan aquifers on
 the  basis of available stratigraphic information was not considered feasible
 for  Sarasota County.  All 12 observations in the water table aquifer have radium-
 226  concentrations greater than 5 pCi/1 with a geometric mean of about 15 pCi/1
 (see Figure 14).  In comparison, the Floridan aquifer has generally lower
 radium-226  concentrations, although 70 percent of the observations also exceed
 the  5 pCi/1 level.  Geometric mean radium content is about 7.5 pCi/1.  Radium
 in the  water table and Floridan aquifers probably represents two independent
                                        62

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             R 17 E
                                          R 19 E
                                        S-34
          GULF OF MEXICO
                         S-5
                         S-16 S-17
                        lS-18l*S-19
                       S-46V* *S'38
                      s-2oYV7s-41
 S-35

V
             01234

             SCALE: MILES
LOCATION OF WELL (SEE APPENDIX 4)

BOUNDARY OF MINERALIZED AREA

HACHURES ON MINERALIZED SIDE
                                      S-11
                                     VENICE
                                   IS-28
                                            S-35*

                                            S-31*
 S-44
                                                S-1
                                                 R 20 E
                                                  S-39
                                                       S-21. .S-22
                                                       S-23* ?S-24
                                                       S-25 *  S-30
                                                                      R 21 E
                                                                              R22E
                                                            SARASOTA COUNTY
                                                  S-9
                                                    co
                                                    01
                                                    00
                                                     S-33
      Figure 13.   Location of wells  sampled for  radium-226  in  Sarasota County.
                                                63

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 1000-
   500-
   200
  100-
o
a
to
gj   50H

5
D
a
a
UJ   20

o
CO
to
    10-
    5.0-
    2.0
   1.0-
     2%
        WELLS LOCATED IN
        WATER TABLE AQUIFER)*
                                              WELLS LOCATED IN
                                              FLORIDAN AQUIFER
            10 15  20
30  40   50  60  70
    PERCENTAGE
Figure  14.
                  Log-probability plot of radium-226 in the water table
                  and Floridan aquifers, Sarasota County.

                                    64
80 85  90    95    98%

-------
populations.  After testing the data sets for similar dispersion, the Mann-
Whitney test produced a test value for "Z" of 3.57 with associated probability
much less than the pre-set alpha of 0.05.  This indicates that the two groups
are probably significantly different and that the water table aquifer has
significantly greater radium-226 than the Floridan.

     Most of the data for the water table aquifer occur in two areas:
1) within a mile of the Gulf Coast, midway between Venice and Sarasota, and 2)
in the area centered in the Myakka Rtver State Park in the northeast part of
the county adjacent to Manatee County (Figure 15).  The coastal wells have
significantly greater radium-226 (mean = 20.8 pCi/1) than inland wells (mean =
13.6 pCi/1) on the basis of the Mann-Whitney test at the 95 percent confidence
level.  Observations of radium-226 in the Floridan aquifer are largely confined
to a mile-wide strip running parallel to the general trend of the coast.
Isopleths of radium-226 on the basis of a 5 pCi/1 contour interval (Figure 16)
suggest that ground water in areas immediately adjacent and within about one-
eighth mile of the coast contains 5 pCi/1 or less radium-226.  Paralleling
this zone is a second one wherein radium exceeds 15 pCi/1.  The inferred
radium-226 high appears to trend eastward and away from the city of Sarasota
in the northern part of the county, possibly extending into south-central
Manatee County.

     Inland of the coastal zone just described there are insufficient data to
characterize radium in the Floridan aquifer.  As shown in Figure 16, levels
east of Venice and southeast of Sarasota are 5 pCi/1 or less but may well be
higher in the area between, as well as in the southern tip of the county.
There are no data for the eastern two-thirds of the county.

     Clearly radium-226 in ground water in Sarasota County is considerably
above levels observed in Polk County and surrounding counties of the primary
study area.  This is true for the water table and Floridan aquifers.  The
Hawthorn Formation, the principal phosphate-bearing formation in the area,
crops out in the northern part of the county and extends toward the coast
(Mansfield, 1942), where it again crops out or is within 20 feet of the land
surface (Sarasota County Health Department, 1976).  In terms of phosphate con-
tent, the Hawthorn is quite low, relative to the Polk County and surrounding
                                     65

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        R 17 E
                      MANATEE CO.
                 R18E    |     R19E
                                                R20E
    GULF OF MEXICO
O
                                                              R 21 E
                                                                            R 22 E
              N
      01234
      SCALE MILES
 WATER TABLE AQUIFER
VALUES ARE RADIUM-226
        IN pCi/l

APPROXIMATE LOCATION OF
CITIES INDICATED
BOUNDARY OF MINERALIZED AREA;
HACHURES ON MINERALIZED SIDE
                                                    SARASOTA COUNTY
                                                                 CHARLOTTE CO.
                                                                                     C/9
                                                                                     CO
                                                                                     CO
                                                                                   O
                                                                                   O
                                                                                   O
                                                                                       LU
                                                                                       O
       Figure 15.   Location  of radium-226 observations in the water table
                    aquifer  in  Sarasota  County.
                                         66

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              MANATEE CO.


                       R 19 E,
FLORIDAN AQUIFER


CONTOUR OF RADIUM-226
   CONTOUR INTERVAL = 5 pCi/l

   El <5 pCi/l
        i pCi/l
                                                 R 21 E
                                                                    R 22 E
                                          SARASOTA COUNTY
                                                     CHARLOTTE CO.
                                                                             |(0
                                                                             [co


                                                                                6
                                                                                O
                                                                                O
                                                                                O
                                                                                c/o
                                                                                HI
                                                                             w  Q
                                                                             o>
Figure  16.   Contour map of radium-226 in theFloridan aquifer
             in Sarasota County.
                              67

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     Another potential  radium source in Sarasota County is monazite sand.
Overstreet (1967) noted large amounts of localized heavy mineral sands in
beaches near Venice in  Sarasota County.  Analysis of these sands (Florida
Department of Health and Rehabilitative Services, 1976) as a part of a study
of radiation in Sarasota County revealed 0.05 to 1.5 percent monazite, a
cerium-lanthanum phosphate containing minor thorium-232, the parent of radium-
228.   Additional analysis for radium-228 in Sarasota County ground water is
strongly recommended, particularly in the water table aquifer.

     Why does Sarasota  County ground water have such high radium-226 levels?
A possible answer^may be suggested by exploring some facts about the general
chemical status of the  Floridan aquifer, radium geochemistry, and regional
ground-water dynamics.   First, what are some of the chemical  attributes of the
Floridan aquifer?  Back (1969) lumped the Floridan aquifers into a single
system and observed that the system is characterized by low total dissolved
solids near the piezometric high in Polk County, with an increase in all
directions toward the coasts and Lake Okeechobee.  In fact, all  fresh water in
Florida is underlain by saline water which ranges in depth from 700 meters  in
the central part of the peninsula to near sea level  along some  shorelines.
Ground water becomes increasingly enriched in chloride, sulfate, calcium, and
magnesium as the coastal areas are approached.   Back also noted that the
increase in these constitutents is not simply due to mixing fresh water and
ocean water as there is too much calcium and carbonate and too  little sodium.
Increasing amounts of limestone are going into solution with  the increased
salinity.   Similar increases in concentration are observed for  magnesium and
sulfate.

     How these factors  influence radium-226 movement is evident from the fact
that radium is an alkaline earth with behavior similar to that  of calcium,
strontium, and barium.   However it is somewhat less mobile.  Radium solubility
in solutions is enhanced at high and low values of pH.   Dissolution of radium
is most enhanced by common cations already in solution.  Of these Na  is most
                        +       2+
important, followed by  K  and Ca  .  Tanner (1964) observed that chloride-rich
waters are either enriched in radium or have greater capability for leaching
radium.
                                     68

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     It is quite possible that increased concentrations of dissolved solids
and calcium in particular, in the ploridan aquifer could help mobilize radium
in the coastal areas.  Secondly, the Hawthorn, though not normally viewed as a
major component of phosphate reserves in the specific study area, apparently
contains sufficient phosphate and associated radionuclides that  chemi-
cally active ground water can leach out radium-226.  Correlation of radium-
226 with undissolved solids is modest (r =0.59) in Sarasota County ground
water.  However, the correlation of radium-226 concentrations with total
dissolved solids is quite strong (r =0-82, Figure 17), tending to support a
cause-effect relationship between dissolved solids and radium.  Regression
analysis of available Sarasota County data suggests that for every additional
100 mg/1 dissolved solids, radium-226 increases about 1 pCi/1.

     Several points should be considered concerning the influence of ground
water movement on radium content of Sarasota County ground water.  The county
is clearly an area of discharge as viewed regionally.  Ground-water development
is relatively light and flow directions are expected to be upward and toward
the coast.  One available analysis of radium from a well completed deep in the
Floridan aquifer contains 21.7 pCi/1 radium and is high in dissolved solids.
This possibly suggests that radium-226 levels in ground water can also be high
without direct leaching of the Hawthorn Formation.  Various speculations
concerning the source of radium in deep, mineralized ground water have been
offered.  Leaching of crystalline basement rocks is favored but the mechanics
are unknown.  It is reasonable to assume that shallow, phosphatic sediments
are not the source of radium in deep ground water.

     Utilization of ground water from the Floridan aquifer for domestic and
municipal water supplies in Sarasota County is hampered by the high total
dissolved solids.  To what extent radium exceeds 5 pCi/1 and is therefore also
a limitation is unknown and worthy of additional data collection.  If radium
concentrations are at or near the 5 pCi/1 limit in those areas of the county
where no data are now available, extensive and rather refined monitoring is
recommended to insure that ground-water quality is preserved and possibly
enhanced as a result of any major land or water use activities and particularly
phosphate mining and chemical processing.
                                   69

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  2500-
             RADIUM-226 = 0.01 (TDS)-0.96

             CORP. COEFF. = 0.82
  2000-
\
ro
E
  1500-
o
CO

Q
UJ

_i
O
CO
CO

Q
1000-
   500-
                 5         10        15

                   DISSOLVED RADIUM-226 (pCi/l)
   Figure 17.   Plot of dissolved solids versus radium-226
               in Sarasota County ground water.
                            70

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                           TEMPORAL  CHANGES IN WATER QUALITY

     Wells sampled in both the 1966 survey and again in 1974-1976 (USGS data
for unacidified samples only; Appendix 1) were checked to ascertain if temporal
changes in water quality could be identified for the three principal aquifers.
The USGS data for unacidified, filtered samples are considered more comparable
to the 1966 FWPCA survey data developed from samples which were filtered and
then acidified.  By comparison, the USEPA data shown in Appendix 1 are from
samples which were acidified, mixed, allowed to stand for dissolution of
solids, and then filtered.  This is believed to produce generally higher
values for dissolved radium.

     Efforts to match identical or similar (in terms of location and producing
aquifer) wells using the 1966 FWPCA survey and the 1974-1976 USGS survey were
disappointing in that only two data pairs involving similar wells could be
identified.  Data interpretation of significance for such a small sample set
is deemed of no significance.  Comparison of the 1966 survey with the 1973-
1976 USEPA data base revealed eight paired sets involving 18 wells.   Only 2 of
the 8 pairs involved identical wells.  Unfortunately, the USEPA data are not
considered comparable to the FWPCA data because of differences in pre-analysis
procedures.

     For the area considered to be mineralized (see Figures 6 and 7), analyses
were selected from the 1966 survey and from the 1974-1976 USGS survey.  Using
the Kruskal-Wallis test (Siegel, 1956), the six data sets as defined by three
aquifers and two sampling periods (see Table 5) were evaluated to determine
whether they were homogeneous.  A test value "H" of 291.35 strongly suggests
that the six data sets are not all equal.  Is this inequality due to differ-
ences exhibited for an aquifer between the two periods of sampling?  Using the
simultaneous multiple comparisons test, (Gibson, 1976) between data pairs
defined by time in each aquifer, no significance was determined at the 80
percent confidence level (Table 5).  That is , radium in ground water is not
significantly different in 1974-1976 as, compared to 1966.

     At best, such testing and resultant findings should be considered as
indicative rather than conclusive in that only two data sets based on one-time
                                     71

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grab samples are available and these are not from the same wells nor are the
analyses by the same laboratory or with the same technique.  Particularly
lacking are time series data showing the variability in radium content for a
given well or series of wells.  On the basis of monthly sampling for 1975,
Keefer  (in preparation) has shown radium in the two municipal wells in  the
Afton, Oklahoma area to vary about 4 pCi/1 annually.  Similar data to show
variability in central Florida ground water are lacking but if similar vari-
ability is present, temporal comparisons of ground water using the approaches
demonstrated herein may be in error.

     No concerted effort has been made to develop time series data for any
aquifer, a deficiency which is most serious with respect to the water table
and Upper Floridan aquifers commonly utilized for single family water supplies.
Data collection has been inconsistent with respect to well locations and pre-
analysis procedures.  Data concerning the extent of mineralization and mining
are also a source of error.  Finally, subdividing an initially limited data
base according to aquifers is a logical approach but one which reduces the
degrees of freedom.  Given this, subtle change in quality might well not be
statistically significant and a much larger data base in terms of the number
of sampling points and replicate sampling may be necessary to establish environ
mental quality trends.  The pronounced paucity of data for the water table (36
analyses) and Upper Floridan  (36 analyses),the aquifers most likely to be
affected, substantiates the need for a greatly increased data base if meaning-
ful comparisons of temporal change in quality are expected.

TABLE  5.  COMPARISON OF 1966 AND 1974-1976 RADIUM-226 DATA FOR THE MINERALIZED
          AREA IN POLK, HARDEE, MANATEE AND HILLSBOROUGH COUNTIES*
Significant
(S) or Mo
Aquifer
Considered


Water table
U.
L.
Floridan
Floridan
No. of
1966

6
22
15
Observations
1974-1976

30
14
10


16
2
2
1 9 6
Mean
**
.9
.07
.03
S

29
1
1
6
.D.

.8
.93
.52
1974-1976
Mean

1.9
1.99
2.46
S.D.

4.17
2.35
4.26
Significant
Change

NS
NS
NS
(NS)




*  Simultaneous multiple comparisons test, a =  .20
** Discounting a maximum value of 76.0 pCi/1, the arithmetic mean  is  5.1  pCi/1
   and no significant difference is indicated
                                    72

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                             LOCAL CONTAMINATION

     Despite a consistent regional or areal pattern of apparent non-degradation
of any of the three principal aquifers in or adjacent to zones of phosphate
mineralization, local  contamination of the water table and probably the Upper
Floridan aquifers is probable but the frequency of occurrence and significance
are unknown.  "Local"  is loosely defined as the general area of a given mine,
slime, pond, processing plant, etc. and extending at most for one or two miles
in any direction and 100 to 200 feet depth.  Seepage from gypsum ponds and
slime ponds has occurred both as percolation through berms or dams and as
sudden collapse of pond substrates due to sinkhole development.  Sinkhole
collapse and similar acute incidents, although dramatic, are uncommon or at
least not well documented in regulatory agency files.  Only a few actual cases
of contamination can be cited..  This might indicate that no serious problems
exist or it may mean that data collection to date is inadequate relative to
hydrogeologic conditions and to land and water use patterns characteristic of
central Florida.  Obviously the issue is rather subjective but considering the
magnitude, duration, and areal extent of the phosphate industry in central
Florida, the near absence of historical radiochemical monitoring data and
interpretive studies is regarded as a shortcoming.  This lack has been docu-
mented herein.  At present and for the foreseeable future, increased monitoring
requirements are being levied on industry and this "is laudable.  It is equally
critical that responsible local, regional, and state agencies have the capabil-
ity to review and react to the data provided and supply additional independent
assessment as necessary.

     Industry maintains that the substrate beneath gypsum ponds are self
sealing due to precipitation of insoluble minerals, particularly calcium
fluorapatite, by neutralization of acidic effluents coming in contact with
bicarbonate ground water and carbonate-rich host rocks.  Opponents to such
waste management practices regard such precipitation and self sealing as
alleged, at best, and that unless ponds are sealed when first installed,
seepage results.  Effluent and gypsum associated with gypsum wastes respec-
tively contain about 91 pCi/1 and 20 pCi/g radium-226 (U.S. Environmental
Protection Agency, 1973).  It is reasonable to expect that wherever highly
permeable  limestone strata of the  Hawthorn  Formation are  present  in mined-out
                                      73

-------
pits used for disposal of slimes or gypsum wastes, seepage is likely to
occur.  Whether such seepage has associated with it sufficient precipitation
to affect sealing of solution channels, fractures, and other secondary
permeability features is unanswered.  By comparison, precipitation and self-
sealing of earthen berms around gypsum ponds does not occur despite intergranular
porosity and permeability (John Barnett, Department of Environmental Regulation,
personal communication, April 13, 1977; remote sensing studies by Coker, 1971,
1972).  Proof of contamination  is somewhat speculative or hypothe-
tical except in a few actual, documented cases. The writers conclude that
additional field study of gypsum ponds is necessary with key emphasis on
ground-water quality monitoring and development of reliable water budgets for
representative ponds.  This would, materially assist in ending the speculation
as to whether seepage is occurring.

     Some consensus exists that contamination of the Floridan aquifer is
local at most and that tracing of contamination from known sources is
difficult to impossible (G.  Parker, Geraghty and Miller,  personal communication,
February 25, 1977 and B. Boatwright, SWFWMD,  personal  communication,
March 30,  1976).   In part, this is attributable to two pronounced but diverse
hydrogeologic characteristics of strata in the study area:   1)  extensive
shallow clay and silt units  with poor permeability and large sorptive capacity,
and 2) cavernous saturated limestones capable of diluting wastes  in extremely
large volumes of native ground water.  Undoubtedly both characteristics serve
to attenuate contamination on a local scale.   Regional  variability in radium
content further obscures the presence and three-dimensional  extent of contaminated
ground water.

     Perhaps the best documentation of local  contamination concerns the C.  F.
Industries,  Inc.  gypsum pile failure in April  1975 as  a result  of sinkhole
collapse (B.  Boatwright, written communication, May 3,  1976).   The sinkhole
collapse was first sighted by Southwest Florida Water  Management  District
(District)  staff on May 17,  1975 in the course of aerial  reconnaissance of the
Alafia Basin.  The District  arranged meetings between  industry  and concerned
public agencies  and served as hydrologic advisor to the Department of Pollution
                                    74

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Control (DPC) which required remedial action  in the form of monitoring and
filling of the sinkhole in a prescribed manner.  The West Central Regional
Office of DPC was the  lead agency in the matter.  Water sampling was done by
the District in cooperation with the Orlando  Radiological Laboratory.  Analyti-
cal methods were outlined by DPC (Tallahasee).

     The stack is located about three miles southeast of Mulberry.   Failure
occurred when a sinkhole about 200 feet in diameter formed and allowed 90,000
cubic yards of gypsum  and 4.5 million gallons of effluent to recharge the
water table and underlying artesian aquifers  in the period April 30  - May 19,
1975.  Thereafter, discharge to the subsurface decreased as a result of gypsum
plugging; however, the gypsum continued to dissolve and a more permanent plug
using clay or other nonreactive material  was ordered by the State Department
of Pollution Control (1975).  Semi-consolidated slimes were used.  Aside from
being acid (pH 2) and  high in radium, the effluent contained high concentra-
tions of fluoride, phosphorus, and sulfate.

     Ground-water monitoring commenced April  30, 1975 with a survey of exist-
ing private and public supply wells.  Data from additional wells constructed
by the company specifically for head measurements and water sampling revealed
the presence of primary and secondary artesian aquifers within the Hawthorn
Formation and a generally northwestward flow  in the upper aquifer within the
vicinity of the sinkhole (based on information prepared by Richard Fountain
and Associates, consultant to C. F. Industries, Inc.).  Understandably,
dispersal of contaminants in ground water downgradient from the sinkhole is
expected and is shown  in Figure 10 prepared from samples collected on July 21,
1975 (B. Boatwright, written communication, May 3, 1976).  Gross alpha values
east, south, and west  of the sinkhole range from 3 to 16 pCi/1  (mean 8.5
pCi/1) and are well below 17 and 35 pCi/1 range (mean 27 pCi/1) evident in
ground water on the north and northwest sides.

     Prior to sinkhole collapse, recharge of  the water table and deeper
aquifers was associated with the presumed presence of a recharge mound having
downward and outward flow components (Florida Department of Pollution Control,
1975).   The State required corrective action  including a monitoring plan by
which C. F.  Industries, Inc. would measure fluid potential (head) and water
                                   75

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                     STATE ROUTE 60
                C.F. INDUSTRIES
                GYPSUM PONDS
                                DOMESTIC WELL
SW
12
A
               SE
               16
               A
A

8.0
WELL GREATER THAN
100 FEET IN DEPTH
WELL OF UNKNOWN DEPTH
GROSS ALPHA, pCi/l
  Figure 18.
Gross alpha  radioactivity in ground water in the
vicinity of  C.F.  Industries, Inc. gypsum ponds.
                               76

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quality in the water table (surficial sand) aquifer as well as in the upper
and lower secondary artesian aquifers below.

     Despite the leakage of contaminants, pronounced changes in water quality,
with the exception of gross alpha are not apparent (Table 6).  Rapid neutrali-
zation of acid wastes occurs and probably quickly reduces the concentration of
radium, although radium data are not available to substantiate this.  Reduction
of the concentration by sorption is likely, particularly in areas underlain by
poorly permeable strata between the ponds and the uppermost limestone units of
the Floridan aquifer (G. Parker, Geraghty and Miller, Inc., personal com-
munication, February 25, 1977).  The gross alpha data indicate elevated levels
of alpha-emitting radionuclides downgradient. Comparison of other
radium and gross alpha data from Shearer et al.  (1966) using multiple regression
techniques shows a rather inconsistent relationship particularly at gross
alpha levels below about 12 pCi/1. Unfortunately, at the time of writing, no
radium data were available for the C. F. Industries, Inc. case.

     Radium concentrations in ground water within roughly a three to six mile
radius of the C. F. Industries, Inc. gypsum ponds range from 0.58 to 6.0
pCi/1.  Wells completed principally in the Lower Floridan average less than
1.8 pCi/1 versus 2.7 pCi/1 for the Upper Floridan.  Thus there appears to be
little difference between aquifers.  Again assuming that there is some con-
sistent relationship between gross alpha and radium, the downgradient gross
alpha values in ground water affected by the sinkhole collapse at C. F.
Industries, Inc. indicate radium contamination, despite the lack of pronounced
change in the other parameters.

     A second case of sinkhole collapse beneath a slime pond occurred in 1968.
Thermal infrared imagery revealed preferential development of sinkholes  along
a lineament which extended through the ponds.  Despite substrate collapse, no
ground-water monitoring data were collected, hence the extent of contamination
is unknown (B.  Boatwright, Southwest Florida Water Management District,
written communication, June 6, 1977).  At the Gardinier, Inc.  plant south of
Tampa, wells in a shallow aquifer downgradient from gypsum piles are report-
edly also affected (James Pool, Department of Environmental Regulation,
                                    77

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personal communication, April  7, 1977).  At the time of writing, no additional
information concerning these incidents was available to the authors.
TABLE 6-  GROUND-WATER QUALITY DATA FROM MONITORING WELLS IN THE VICINITY OF
          THE C. F. INDUSTRIES, INC. GYPSUM POND NEAR MULBERRY

                                   WELL   LOCATION
Station*
Parameter**
PH
Dissolved solids
Total solids
Acidity
Alkalinity
Hardness
Ca
Mg
so4
F
P04
Total P (as P04)
Si02
Gross alpha
A D J A C
Domestic
Well
8.0
269
272
10
160
78.7
32
14.3
10.5
0.434
0.986
0.17
5.8
<2
E N T
P2-2
8.1
210
230
10
200
102
12
17.5
2.7
0.8
0.078
0.19
9.0
5
DOWN
Pl-3
8.0
218
240
12
248
124
15
21
1.8
0.47
0.01
0.096
7.9
35
G R A D
Pl-1
7.5
283
298
44
268
155
21
25
8.0
0.55
0.003
0.12
5.8
32
I E N T
P2-2
8.5
167
236
0
154
77
13
10.7
47.5
0.9
0.094
1.01
3.4
28
*  Station identifiers located on Figure 10..
** Chemical analysis by Florida Department of  Environmental  Regulation;
   sampling data July 21, 1975

     Water losses via seepage from three slime ponds  studied by Zellars-
Williams (1977) under contract to the U.S. Bureau of  Mines amounted to 10 to
22 percent of the total water used for mining  and beneficiation.   It is reason-
able to assume that seepage from gypsum ponds  also enters the water table at a rate
which in some locations may well equal  or exceed that of slime ponds if
dissolution of carbonate strata by acidic waste water occurs.  Admittedly this
is speculative because water budget and water  quality data to ascertain if
seepage from gypsum ponds occurs are notoriously lacking.   To the authors'
                                    78

-------
knowledge, monitoring of shallow ground water around gypsum ponds in central
Florida has been limited to the sinkhole collapse incident near Mullberry.  We
conclude that additional monitoring studies of the effects of gypsum ponds on
shallow ground-water quality are needed and that data should be collected to
document changes in quality, if any, that follow mining and reclamation.

     Of the 80 privately-owned wells sampled in the 1966 survey, two (wells 26
and 29) contained markedly elevated concentrations of radon (22,700 to 28,800
pCi/1), radium-226 (49 to 76 pCi/1), gross alpha (75 to 97 pCi/1), nitrate
(16 to 26 mg/1), and sulfate (120 to 220 mg/1).  Unfortunately well depths
were not stated, hence the aquifer(s) involved is unknown.  Well 26 is used
for industrial water supply and is located two miles west of Agricola.   The
water may be naturally deteriorated insofar as water quality is highly variable
in the area, particularly in the water table aquifer (B. Boatwright, SWFWMD,
personal communication, March 30, 1977).  Surrounding land use is predominantly
rangeland.  The nearest phosphate mining and processing activity is within one
mile to the south.  Well 29 is located on Bovis Road, two and one-half miles
west of Fort Meade.  Again, surrounding land is predominantly grassland with
the nearest phosphate mining approximately one mile south.

     Radium-226 concentrations in excess of 5 pCi/1 are summarized in Table 7.
Of the 122 analyses from the 1973-1976 EPA and USGS surveys, only 12 or about
10 percent exceed 5 pCi/1.  The two highest values of 22 and 90 pCi/1  are from
a water table well in a mineralized but unmined area.  This may indicate that
high radium can also be a natural phenomenon and not necessarily indicative of
contamination.  Hutchinson (1975) noted this natural condition but gave no
specific data.  Wells in the nonmineralized area contain 5.2 to 14.7 pCi/1
radium-226 which is considered to be a natural condition owing to the location
and depth of the wells.  Only two wells in the mined areas contain elevated
levels of radium and these are from the Upper and Lower Floridan aquifers.  No
conclusion is drawn as to whether these represent natural or contaminated
conditions.  However, the concentrations are similar to peak values reported
for wells of similar depth in mineralized, unmined areas and in nonmineralized
areas.
                                      79

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     TABLE 7.  SUMMARY OF 1973-1976 RADIUM-226 DATA EXCEEDING 5 pCi/1
                                                   Principal  Aquifer and
Well No.
EP5-22
GP40-34
GP95-22
EP47-6
GP59-4
GP76
EMI 4-2
EP69-18
EP69-14
EP85-12
GP89-14
EP91-17
Total/Cased
Land Use Depth/ Depth
Mineralized, unmined 1801
39/34
27/22
Mineralized, mined -/-
-/-
Mineralized -/-
400/90
Nonmineralized 800/-
200/99
705/-
220/-
200/-
Radium Content, pCi/1
WT UF LF
15.3 
7.7
22,90
6.0
14
5.3
12.1 
14.7 
7.3
7.3 
5.20.052
10.6+0.106

1.53





0.121
0.147

0.073


     Use of connector wells to dewater surficial  sand and upper Hawthorn
strata was initially done with little information on the radiochemical  quality
of ground water allowed to recharge the deeper aquifers. Recent permits for
consumptive use of water issued by the Southwest  Florida Water Management
District require monthly water analyses of production wells and connector
wells.  Included in the minimum of 15 parameters  for analysis is gross  alpha
radiation.  If gross alpha exceeds 15 pCi/1   analysis for radium-226 and total
radium is also required.  These data are reported to SWFWMD on an annual basis
for production wells and monthly for connector wells.  There is provision for
additional testing as necessary and for administrative  action  if signifi-
cant harm of receiving waters is indicated by the data (B. Boatwright,  SWFWMD,
written communication, June 6, 1977).  Recent management practices emphasize
stricter controls on the quality of water recharged to the Floridan aquifer
system.  This is worthwhile insofar as there is some difference of opinion
concerning the radium content of shallow ground water.   Hutchinson (1975)
reported excessive radium concentrations whereas  preliminary radium data
supplied by industry for two mines where connector wells are in use show
                                   80

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concentrations of 3 pCi/1 or less in recharge water (B. Boatwright, written
communication, June 6, 1977).

     Abandonment procedures for connector wells require grouting but there is
open concern by regulatory and management agencies that the rapid turnover of
wells, necessitated by the pace of dewatering, stripping, and reclamation
activities, results in improper abandonment (D. Guthrie, Polk County Depart-
ment of Environmental Control, personal communication, June 2, 1977; B. Boat-
wright, SWFWMD, personal communication, June 3, 1977).  There are no require-
ments for monitoring of ground-water quality after stripping and reclamation
is completed.  It is also unknown if radium increases in very shallow ground
water as a result of stripping and particularly as a result of disruption of
the leach zone materials and shallow aquifer.   Additional geochemical or
hydrogeochemical studies are recommended to determine whether shallow ground
water may possibly become enriched in radium relative to pre-mining concentra-
tions.  Although available radiochemical data do not indicate this problem,
the data that have been gathered are decidedly deficient for environmental
monitoring purposes relative to the scale of phosphate industry activity.   The
water table in mined areas is poorly monitored in terms of water quality,
although recent SWFWMD permits for consumptive use will require more data  to
close this gap.

     As presently conceived, the proposed Underground Injection Control
Program of the USEPA would include the practice of using connector wells to
move water from the water table and Upper Floridan aquifers to the Lower
Floridan aquifer.  Monitoring of water quality will  be a necessary part of
such monitoring.  Control over seepage of contaminated, radioactive gypsum
pond water would not be included in these regulations.  It is recommended  that
the use of connector wells be carefully regulated in terms of the control
program and that seepage from gypsum ponds be carefully studied as to magnitude
and effects to determine if corrective action is necessary.
                                    81

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              ADEQUACY OF INDUSTRY RESPONSE TO THE DRI PROCESS

     Three Development of Regional Impact applications (Borden, Inc., 1975;
W.R. Grace and Co., 1975; Phillips Petroleum Co., 1975) for permission to
conduct surface mining in portions of Hillsborough, Desoto, Manatee, and
Hardee Counties were reviewed for their approach to prediction of radiochemical
impact on ground water as a result of mining and related operations.  With
rare exception, qualitative statements based on the limited radiochemical data
existing prior to 1975 and arguments or positions based on theory were advanced
to  indicate that mining would have no or little adverse impacts.

     Concerning radiation, one report (Borden, Inc., 1975, p.  27-29) discusses
uranium but not radium.  Unsubstantiated conclusion is reached that "no problems
with regard to radiochemical pollution of air or water, or of employee exposure,
are anticipated...."  Elsewhere (p. 29) the report mentions solution openings
in  the Hawthorn Formation having been discovered onsite, yet design and con-
struction of slime ponds only incorporates seepage control measures for dams.
No  mention is made of the overall water balance in the ponds,  despite the fact
that at least 2.5 square miles of ponds will be floored in limestone, and have
heads at least thirty feet above those in the Hawthorn Formation (p. 110 and
exhibit 76).

     Of the three DRI applications reviewed, only one, (Phillips Petroleum
Co., 1975) included a preoperational health physics and environmental study
including a terrestial gamma radiation survey and measurement of radioactivity
concentrations (radium-226, polonium-210, lead-210, natural uranium) in air,
water and vegetation.  There is mention (p. 37) of plans for water quality
monitoring through mining and reclamation, yet no details as to parameters,
sampling locations or depths, or frequency are given.   The conclusion is
reached (p. 36) that no degradation of water quality in the water table aquifer
should result.  Comparison (p. 53-54) of waste water quality relative to that
of  adjacent ground water at two settling ponds indicates no deterioration as a

                                       82

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result of high quality water in the ponds and very  low seepage.  Appendix A of
the same report purports to estimate water quality  before, during, and after
mining but this is not accomplished and no radiochemical measurements of any
kind are provided.  Impacts of mining on the hydrologic system are addressed
only in terms of flows and head declines due to dewatering or pumping.  Long
term (post mining and reclamation) effects and radiochemical water quality
impacts are not addressed for the water table aquifer or for either of the two
principal artesian aquifers.

     Proposed mining of another large tract (18,685 acres total; 12,845 acres
mined) in Manatee and Hillsborough Counties involves surface water quality
monitoring only to ensure discharge in accordance with pertinent regulations
(W.R. Grace and Co., 1975, p. 23).  Although some seepage into the shallow
aquifer is acknowledged (p. 24), the dissolved mineral load is considered
minor and no direct discharge of liquid wastes to ground water is expected
It is implicitly assumed that seepage will contain  only dissolved solids,
including radionuclides, although the onsite occurrence of a prominent system
of collapse features is noted (p. 68).  No mention  of their potential role in
contamination incidents is made.  Monitoring of ground water will be limited
to measurement of head and chloride concentration in the water supply wells
tapping the Floridan aquifer.

     We recognize that three DRI applications are a rather small  sample and
that they contain only a portion of the data reviewed and required by public
agencies such as SWFWMD and the regional planning councils.   Additional  studies
and data concerning water use and hydrology are increasingly being required as
part of the permitting procedures or development orders issued subsequent to
the DRI application.  For example, connector wells  arid water supply wells  must
be monitored periodically, often monthly, for flow, gross alpha,  and other
nonradiochemical parameters.  If gross alpha exceeds some limit,  initially set
at 2 pCi/1 and more recently to 15 pCi/1, radium-226 analysis is  required.   In
some cases a 5 pCi/1 gross alpha screening level is used.   If radium-226
exceeds 3 pCi/1, radium-228 must also be determined (Gordon F. Palm, private
consultant, written communications, June 16, July 25, 1977 ; Barbara A.  Boat-
wright, SWFWMD, written communication, June 6, 1977).
                                   83

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                                REFERENCES
Ahrens, L.H., 1957, Lognormal-type distributions,  Pt.  3 of the lognormal
     distribution of the elements-a fundamental  law of geochemistry and its
     subsidiary:  Geochim.  et Cosmochim.  Acta,  v.  11,  no,  4,  p.  205-212.

Back, W., 1969, Chemical hydrogeology of  the carbonate peninsulas  of Florida
     and Yucatan:  Ph.D. dissertation, Univ.  of Nevada Reno,  71  p.

Battelle Memorial Institute, 1971, Inorganic fertilizer and phosphate mining
     industries - water pollution control:   Final  report to U.S.  Environ.
     Protection Agency, Washington, D.C., under grant  12020FPD.

Borden, Inc., 1975, Development of regional  impact (DRI) application for
     development approval for the Big Four  Mine,  Hillsborough County,
     Florida:  submitted by Smith-Douglas Div.  of  Borden Chemicals, Borden,
     Inc., Plant City, Florida to Board of  County  Commissioners  and the
     Florida Division of State Planning,  212 p.

Cathcart, J.B., 1963a, Economic geology of  the  Chicora quadrangle,  Florida:
     U.S. Geol. Survey Bull. 1162-A, 66 p.

            _, 1963b, Economic geology of  the Keysville quadrangle,  Florida:
     U.S. Geol. Survey Bull.  1128,  82 p.

    	, 1963c, Economic geology of  the Plant  City  quadrangle,  Florida:
     U.S. Geol. Survey Bull.  1142-D,  56 p.

            _, 1964, Economic  geology  of the  Lakeland  quadrangle,  Florida:
     U.S. Geol. Survey Bull.  1162-G,  128 p.

	, 1966, Economic  geology  of the  Fort Meade  quadrangle,  Polk
     and Hardee Counties, Florida:  U.S.  Geol.  Survey Bull.  1207, 93 p.

Cathcart, J.B., and McGreevy, L.J., 1959, Results of geologic  exploration  by
     core drilling, 1953, land-pebble phosphate district,  florida:   U.S. Geol
     Survey Bull. 1046-K, 298 p.

Coker, A.E., 1971, Remote sensing of  phosphates and  fluoride pollution  in  the
     karst terrain of Florida:   paper presented at National  Water Well  Assoc.
     Ann. meeting, Las Vegas, Nevada.

	, 1972, Discrimination of flouride  and phosphate contamination in
     central Florida for analysis of  environmental effects:  4th annual  earth
                                   84

-------
     resources program review-National  Aeronautics  and  Space  Administration,
     Manned Spacecraft Center,  Houston, Texas,  12 p.

Datagraphics, Inc.,  1971,  Inorganic chemicals  industry  profile  (updated):
     Final  report to U.S.  Environ.  Protection  Agency, Washington,  D.C.,
     under  grant 12020EJI.

Denham, D.H., and Waite,  D.A.,  1975,  Some practical  applications of  the
     log-normal  distribution for interpreting  environmental data:  Paper
     presented at the 20th  Ann.  Mtg.  of the  Health  Physics  Society,  Buffalo,
     NY, July 14-17, 1975,  31  p.

Dunn, O.J., 1964, Multiple  comparisons  using rank sums:   Technometrics, v.  6,
     p. 241-252.

Fitzgerald, J.E., Jr., Guimond,  R.J., and Shaw,  R.A., 1976, A preliminary
     evaluation of the control  of indoor radon  daughter levels  in  new
     structures:  U.S. Environ.  Protection Agency,  Office of  Radiation
     Programs, Criteria and Standards Div.,  Washington,  D.C., Rpt.
     no. EPA-520/4-76-018,  62 p.

Florida Department of Health and Rehabilitative  Services, 1976, Study of
     radiation environment, Sarasota County, Florida:   unpublished report
     dated  May 20, 1976,  10 p.

Florida Department of Pollution  Control, 1975,  letter of June 12 from
     S. Winn, Deputy Executive Director to M.L.  Walton,  Acting  Plant
     Manager, CF Chemicals, Inc., Bartow, Florida,  6 p.

Gibbons, J.D., 1976, Nonparametric methods for  quantitative analysis:  Holt,
     Rinehart and Winston,  New York,  463 p.

Golden, J.C., 1968,  Natural background  radiation levels  in  Florida:  Sandia
     Laboratory, Albuquerque, SC-RR-68-196 (May), 27 p.

Guimond, R.J., and Windham, S.T., 1975  Radioactivity distribution  in phosphate
     products, by-products, effluents,  and wastes:   U.S.  Environ.  Protection
     Agency, Office of Radiation Programs, Criteria  and  Standards  Div.,
     Washington, D.C., Tech note ORP/CDS-75-3,  30 p.

Hackbarth,  D.A., 1971, Field study of subsurface spent  sulfite  liquor
     movement using earth resistivity measurements:  Ground Water, v. 9,
     no. 3, p. 11-16.

Hoppe, R.W., 1976, Phosphates are vital to agriculture  - and  Florida mines
     for one-third of the world:   Engineering  and Mining Jour., May  1976,
     p. 79-89.

Hursh, J.B., 1953, The radium content of public  water supplies:  Univ. of
     Rochester, Rochester,  NY,  Rep. UR-257.

Hutchinson, C.B., 1975, Effects  of strip mining  on  shallow  aquifer systems
     in phosphate district:  U.S. Geol. Survey  Prof. Paper  975, p. 89.
                                   85

-------
Irwin, G.A.,  and Hutchinson,  G.B.,  1976,  Reconnaissance water sampling for
     radium-226 in central  and northern Florida,  Dec.  1974 - March 1976:
     U.S.  Geol. Survey Water  Res.  Inv.  76-103,  16 p.

Kaufman, M.I., and Dion,  N.P., 1967,  Chemical  character of water in the
     Floridan aquifer in  southern  Peace River  basin,  Florida;  U.S. Geol.
     Survey in cooperation  with the Florida Bur.  of Geol., Map Series 27.

Keefer, Douglas H., in preparation, Radiation  exposure in public ground water
     supplies, Ottawa County, Oklahoma:  U.S.  Environ. Protection Agency,
     Robert S. Kerr Environ.  Res.  Lab., Ada,  Oklahoma, 57 p.

Koch, G.S., and Link, R.F-, 1971,  The coefficient of variation - a guide to
     the sampling of ore  deposits:   Econ.  Geol.,  v.  66, p. 293-301.

Koczy, F.F.,  1958, Natural  radioactivity as a  tracer in the ocean:  Proc.  2nd
     U.N.  Int. Conf. Peaceful Uses  of Atomic  Energy,  United Nations, NY.

Le Grand,  H.E., 1968, Monitoring of changes in  quality of ground water: Ground
     Water, v. 6, no. 4,  p. 14-18.

Mansfield, G.R., 1942, Phosphate resources of  Florida:  U.S. Geol. Survey
     Bull. 934, 82 p.

Merkel, R.H., 1972, The use of resistivity techniques  to delineate acid mine
     drainage in ground water:  Ground Water,  v.  10,  no. 5, p. 38-42.

Mills, L.R.,  and Laughlin,  C.P., 1976, Potentiometric  surface of Floridan
     aquifer-May 1975, and  change  of potentiometric surface 1969 to 1975,
     Southwest Florida Water  Management District  and adjacent areas:
     U.S.  Geol. Survey Water  Resources Inv. no.  76-80.

Miyake, Y., Sugimura, Y., and Tsubota, H., 1964,  Content of uranium, radium
     and thorium in river waters in Japan: In  The Natural Radiation Environ-
     ment, Rice Univ. Houston, Texas, Adams,  J.A.S.,  and Lowder, W.M., eds.,
     p. 219-225.

Osmond, O.K., 1964, The distribution of the heavy radioelements in the rocks
     and waters of Florida:  j The Natural Radiation  Environment, Rice Univ.,
     Houston, Texas, Adams, J.A.S., and Lowder,  W.M.,  eds., p. 153-159.

Overstreet, W.C., 1967, The geologic occurrence of monazite:  U.S. Geol.
     Survey Prof. Paper 530,  327 p.

Parker, C.G., Ferguson, G.E., Love, S.K.,  and  Others,  1955, Water resources
     of southeastern Florida:  U.S. Geol.  Survey  Water Supply Paper 1255,
     965 p.

Peek, H.M., 1958, Ground-water resources of Manatee County, Florida:  U.S.
     Geol. Survey Report  of Inv. 18, prepared  in  cooperation with the Florida
     Geol. Survey, Board  of County Commissioners  of Manatee County, and the
     Manatee River Soil Conversation District,  99 p.

                                       86

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Phillips Petroleum Co., 1975, Development of regional impact (DRI) application
     for development approval for phosphate mining and benefication in De Soto
     and Manatee Counties, Florida:  submitted by Phillips Petroleum. Company,
     Bartlesville, Oklahoma to Boards of County Commissioners and the Division
     of State Planning, 419 p.

Pride, R. W., F- W. Meyer, and R. N. Cherry, 1966, Hydrology of Green Swamp
     Area in Central Florida:  U.S. Geol. Survey, in cooperation with the
     Florida Geol. Survey, the Florida Div. of Water Resources and Conserva-
     tion, and the Southwest Florida Water Management District, 137 p.

Robertson, A. F., 1973, Hydrologic Conditions in the Lakeland Ridge Area of
     Polk County, Florida:  U.S. Geol. Survey Report of Inv. 64, prepared in
     cooperation with the Southwest Florida Water Management District, The
     City of Lakeland, Florida, and the Bur. of Geol., Florida Dept. of
     Natural Resources, 54 p.

Samuels, L.D., 1964, A study of environmental exposure to radium in drinking
     water: j_n_ The Natural Radiation Environment, Rice Univ., Houston, Texas,
     Adams, J.A.S., and Lowder, W. M. eds., p. 239-251.

Scott, R. C., Barker, F.B., 1962, Data on uranium and radium in ground
     water in the United States:  U.S. Geol. Survey Prof. Paper 426; 36 p.

Shearer, S. Smith, B., and Rushing, D. E., 1966, Draft report of radium-226
     and radon-222 concentrations in central Florida ground waters:
     Appendix B j_n_ Reconnaissance study of radiochemical pollution for phosphate
     rock mining and milling, 1973, U.S. Environ. Protection Agency, National
     Field Inv. Center-Denver, p. B1-B29.

Siegel, S., 1956, Nonparametric statistics for the behavioral sciences:
     New York, McGraw-Hill, 312 p.

Sinclair, A.J., 1974, Selection of threshold values in geochemical data using
     probability graphs:  Jour, of Geochem. Explor., v. 3, no. 2, p. 129-149.

Spaulding, R.F., 1972, The contemporary geochemistry of uranium in the
     Gulf of Mexico distributive provice:  Ph.D. thesis, Texas A&M Univ.

Springer, Melvin D., 1976, Research for the development of guidelines for
     conducting and analyzing an environmental quality study to determine
     statistically meaningful results:  Univ. of Arkansas, Water Resources
     Research Center Pub. 37, in cooperation with Engineering Experiment
     Station Research Rpt. 26, 163 p.

Stewart, H. G., Jr., 1966, Ground-water resources of Polk County:  U.S. Geol.
     Survey Report of Inv. 44, prepared in cooperation with the Div. of Geol.,
     the Board of County Commissioners of Polk County, and the Southwest
     Florida Water Management District, 170 p.
                                       87

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Stewart, J. W., Mills, L.R., Knochenmus, D.D., and Faulkner, F.L., 1971,
     Potentiometric surface and areas of artesian flow, May 1969, and change
     of potentiometric surface 1964 to 1969, Floridan aquifer, Southwest
     Florida Water Management District, Florida:  U.S. Geol. Survey Hydrologic
     Inv. Atlas HA-440.

Stellar, R. L., and Roux, P., 1975, Earth resistivity surveys - a method for
     defining ground-water contamination:  Ground Water, v. 13, no. 2,
     p. 145-150.

Stowasser, W. F-, 1976, Phosphate Rock:  jjn Mineral  Facts and Problems, U.S.
     Bur. of Mines Bull. 667, p.  819-834.

Tanner, A. B., 1964, Physical and chemical  controls  on distribution of
     radium-226 and radon-222 in  ground water near Great Salt Lake, Utah:
     _i_n_ The Natural Radiation Environment,  Rice Univ., Houston, Texas, Adams,
     J. A. S., and Lowder, W.M.,  eds., p. 253-276.

Thatcher, L. L., Janzer, V.J., and Edwards, K.W., 1977, Methods for determina-
     tion of radioactive substances in water and fluvial sediments:  U.S.
     Geol. Survey Techniques of Water-Resources Inv.  Book 5 (Laboratory
     Analysis), Chap.  A5, 95 p.

Todd, D. K., Tinlin, R.M., Schmidt, K.D., and Everett, L.G., 1976, Monitoring
     ground-water quality - monitoring methodology:   Final  report to U.S.
     Environ. Protection Agency,  Office of  Research  and Development, Environ.
     Monitoring and Support Lab., Las Vegas, NV, under contract 68-01-0759,
     report no. EPA-600/4-76-026, 154 p.

Tokarev, A.N., and Shcherbakov, A.V., 1956, Radiohydrogeology ("Radiogidro-
     geologiya"):  Gosgeoltekhizdat.   (English trans.: U.S. Atomic Energy
     Comm. Rpt., AEC-tr-4100, 1960, 346 p.).

U. S. Environmental Protection Agency, 1973, Reconnaissance study of radio-
     chemical pollution from phosphate rock mining and milling:  Office of
     Enforcement, National Field  Inv. Center-Denver,  Denver, Colorado, 46 p.

	, 1975 Preliminary findings   radon daughter levels in structures
     constructed on reclaimed Florida phosphate land:  Office of Radiation
     Programs, Criteria and Standards Div., Tech note ORP/CSD-75-4, 7 p.

            1976a, Drinking water regulations (Radionuclides):  Federal
     Register, v. 41, no. 133, July 9, 1976, p. 28402-28409.

	, 1976b, Florida phosphate lands, interim recommendations for
     radiation levels:  Federal Register, v. 41, no. 123, p. 26066-26068.

Warner, D. L., 1974, Rationale and methodology for monitoring ground water
     polluted by mining activities:  Final report to U.S. Environ. Protection
     Agency, Office of Research and Development, Mat'l Environ. Research
     Center, Las Vegas, NV, under contract 68-01-0759, report no.
     EPA-600/4-74-003, 76 p.

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Wayne Thomas, Inc., 1976, Florida pebble phosphate field land ownership map
     (1) northern portion; (2) southern portion:  Wayne Thomas, Inc.,
     private consultant, Tampa, Florida, 2 sheets.

Williams, E. G., Golden, J.C., Jr., Roessler, C.E., and Clark, y., 1965,
     Background r&diation in Florida:   Div. of Rad. and Occupational  Health,
     Florida State Board of Health, RH-00054-02, 60 p.

Wilson, W.E., 1975, Ground-water resources of De Soto and Hardee Counties,
     Florida:  U.S. Geol. Survey open  file report prepared in cooperation with
     Florida Bur. of Geol., 189 p.

W.R. Grace and Co., 1975, Development  of regional impact (DRI) application
     for development approval  for the  Four Corners mine, Hillsborough and
     Manatee Counties, Florida:  submitted by W.R. Grace and Co.,  Bartow,
     Florida to the Boards of County Commissioners and  the Florida Division
     of State Planning, 160 p.

Zellars and Williams, Inc., 1977, Water recirculation system balance  of central
     Florida phosphate mining:  prepared under contract to U.S. Bur.  of Mines,
     USBM open file report OFR 120-77  by Zellars-Wil1iams, Inc., Lakeland,
     Florida, 34 p.
                                        89

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o
                                     APPENDIX 1.   DISSOLVED RA-226 CONCENTRATION (pCi/1) IN GROUND WATER IN THE CENTRAL FLORIDA PHOSPHATE DISTRICT

                     Site number prefixes indicate the Agency originating the analysis: E - U.S.  Environmental  Protection Agency,  G - U.S.  Geological  Survey.   The second
                     letter indicates the county: P - Polk Co., M - Manatee Co., HB - Hillsborough Co. ,  H - Hardee Co,  D-DeSoto Co.   The  first  letter  indicates  the
                     presence (M) or absence (N) of mineralization.  Mineralized areas are further divided into mined and nonmined classes by use of a second  letter,
                     M or N, as appropriate.  See Appendix 3. for procedure used to locate wells.   Data  from Irwin and Hutchinson  (1976)  are located by latitude and
                     longitude only and are additionally located herein by township and range.   Aquifers are defined as follows:   LF - Lower Floridan  aquifer,  UF - Upper
riorioan aquire
Site No.
Classification
GP1
N
EP2-15
M-N
EP3-19
M-N
EP4-20
M-N
EP5-22
M-N
EP6-21
M-N
EP7-7
M-N
EP8-8
N
GP8A
N
EP9-4
N
EP10-3
N
GPU
N
N
EP13-11
M-N
EP14-18
M-M
EP15-19
M-M
r, wi - water laoie aquirer.
Name or Latitude and Longitude
USGS (acidified sample)
Trailer park, Lakeland
Trailer park, Lakeland
Trailer park, Eaton
Trailer park, Lakeland
Trailer park, Lakeland
Private well, Auburndale
Trailer park and camp,
Haines City
USGS (acidified sample)
Lake Alfred well 2
Lake Alfred well 1
USGS (acidified sample)
Haines City well no. 4
Trailer park
Central Avenue well 9,
Lakeland
Well 20, Lakeland
T. R. S.
26.27.11
27. 23. lied
27.23.20cc
27.23.28ab
27.23.28bd
27.23.29ad
27.25.21ab
27.26.24cd
27.26.28
27.26.32ad
27.26.32bd
27.27.4
27.27.29ad
28.23.20bc
28.23.25ca
28.23.35ab
Date
Sampled
1/03/75
8/21/73
8/21/73
8/21/73
8/21/73
8/21/73
8/20/73
8/21/73
1/03/75
7/30/74
7/30/74
1/03/75
7/30/74
8/21/73
8/01/74
8/01/74
Total /Depth
depth/ cased
(ft)
362/80
123/-
-/-
206/-
180/-
135/-
150/-
125/-
500/100
550/100
550/95
430/100
810/107
82/-
703/238
-/100
Aquifer
LF
LF
?
LF
LF
LF
LF
LF
LF
LF
LF
LF
LF
UF
LF
UF
Radium-226
1 .8
0.77
1.2 .' .
1.7 > .
15.3 *1.
1.8 i .
1.5 " .
2.4 t ,
1.8
1.8 
2.1 
.99
0.51  .
2.3  .
0.73  ,
1.6 i .
(pCi/D

007
036
068
53
036
045
.072

.054
.042

,025
.046
.029
.048

-------
GP15A-19
M-N
GP15B
M-N
EP18-6
M-N
EP19-1
M-N
EP20-2
N
GP20A
N
EP21-1
N
EP22-16
N
EP23-6
N
EP24-31
M-M
EP25-20
M-N
EP26-21
M-N
GP27-32
M-M
EP28-22
M-N
EP29-4
M-N
EP30-5
M-N
GP31-33
M-M
GP32-44
M-M
EP33-7
M-M
EP34-23
M-N
USGS monitor well
USGS (acidified sample)
Trailer park, Auburndale
Trailer park, Lakeland
Winterhaven well 7,
Inwood Plant
USGS (acidified sample)
Winterhaven well 8,
3rd street Water Plant
Private well, Lake Hamilton
Dundee wel 1 2
Mulberry'1 '
Drane Airfield Rd. well 16,
Lakeland
Piper Well 35, Lakeland
Mulberry'2'
West Coast Grove, Cornet Road
at Hwy. 60
Trailer park and restaurant,
Mulberry
Private well , school
12)
757156111 - 124^ '
USGS monitor well
Hwy 7 - One mile south of
air base
Multi -family supply well,
Gordonville
28.24.9dd
28.25.11
28.25.17ab
28.25.18cd
28.?5.24bb
28.26.28
28.26.29dd
28.27.28ac
28.27.28ac
29.23.lbb
29.23.4bd
29.23.9ac
29.23.13cd
29.23.30db
29.23.32ad
29.Z3.32ad
29.24.18ba
29.24.20dd
29.25.22cc
29.25.22da
3/04/76
1/03/75
8/20/73
8/21/74
7/30/74
1/06/75
7/30/74
8/21/73
7/30/74
12/04/74
8/01/74
8/01/74
12/04/74
9/10/74
8/21/73
8/21/73
12/04/74
2/13/76
9/10/74
8/20/73
58/31
362/80
110/-
100/-
601/186
312/100
734/-
320/-
755/152
?/?
700/103
550/203
95/53
-/-
168/-
97/-
120/170
37/32
27/14
250/-
UF
LF
UF
UF
LF
LF
LF
LF
LF
LF
LF
LF
UF
?
LF
UF
UF
WT
WT
LF
1.2
1.6
2.8 +
4.4 
2.4 <
3.8
1.0 i
1.7 ^
0.6 t
0.13
0.92 i
0.60 
0.61
3.0 
0.19 
0.18 
0.16
.64
<2.0
1.2 *


.056
.044
.048

.03
.068
.018

.037
.03

.09
.017
.016


.036

-------
GP35-60A
M-M
GP35B-46
N
GP35C-34
M-N
EP37-3
N
EP38-9
M-M
EP41-23
M-M
EP42-24
M-M
EP43-10
M-M
EP44-25
M-M

GP45-10
M-N
GP45A-2
M-M
EP46-26
M-M
GP47-6
M-M

GP47A-3
M-M
EP48-28
M-M

EP49-9
M-N
EP50-10
M-N
EP51-11
M-N
EP52-12
M-N
GP52A-42
M-N
Domestic well, Bartow
USGS monitor well
USGS monitor well
Private well, restaurant,
Lake Wales
Private well, trailer park,
Mulberry
Mulberry well 1
Mulberry well 2
Private well, trailer park
Mulberry
Mulberry Heights well

Domestic well
751201422
Sand mine tailings area
Industrial well
SWFWMD observation
well-B(3]

USGS monitor well
Hwy 640 E. of Hwy 555

Bartow well 1, Power Plant
Bartow well 2, Power Plant
Bartow well 10, Water Plant
Bartow well 3
Monitor well (4)

29.25.23dc
29.26.14dc
29.26.19da
29.27.27cd
30. 23. led
30.23.12bc
30.23.12bc
30.23.14aa
30.23.14aa

30.23.21ca
30.23.35cc
30.23.36bb
30.24.12bb

30.24.35ca
30.24.35ab

30.25.5cc
30.25.5cc
30.25.5cc
30.25.5cc

30.25.5dd
12/11/74
3/18/75
3/19/75
8/22/73
8/21/73
9/10/74
9/10/74
8/21/73
7/30/74

12/10/74
12/04/74
9/10/74
1/08/75

2/26/75
9/10/74

7/30/74
7/30/74
7/30/74
7/30/74

12/04/74
-/-
22/17
39/34
405/-
156/-
776/78
833/80
258/-
-/-

80/60
24/21
-/-
-/-

22/17
-/-

600/100
765/125
683/59
663/565

1348/1270
LF 0.72
WT 2.2
WT 7.7
LF 0.23 ' .018
LF 3.5 .07
LF ,2.0
LF <2.0
LF 1.9 t .019

? 1.8 i .054
UF 1.5
WT 0.26
? 2.0
IIP r n
Ur 6.0
UF 0.64
? r r '
5.5 - .11
LF 2.24 .045
LF 2.3 - .046
LF 1-4 i .042
LF 2.6 _ .052

LF 1.2

-------
EP53-15
M-N
EP54-14
M-N
EP55-13
M-N
GP56-54
M-N
EP57-8
M-N
GP57A-43
M-N
GP58-67
M-M
GP59-4
M-M
GP60-2'4'
M-M
6P61-34
M-M
GP62-72
M-M
GP63-73
M-M
GP63A-14
N
GP65-75
M-M
GP66-76
M-M
EP67-13
N
EP68-2
M
GP68A-4
N
EP69-18
N
GP69A-35
M-N
Bartow well 4, Commerce Park
Bartow well 7, Floral Avenue
Bartow well 5, Jordan Pk.
Jordan Pk.
Lake Garfield
Domestic well
Industrial well
Nursery well, Bartow
Private well
Private well
Industrial well 30A
Industrial well 46A
Domestic well
Monitor well
Monitor well
Motel and restaurant,
Lake Wales
Camp ground., Lake Wales
USGS monitor well
Trailer park, Babson
USGS monitor well
30.25.7cb
30.25.7dc
30.25.8cb
30.25.8dc
30.25.12ad
30.25.14
30.25.15bc
30,25.17ab
30.25.18ca
30.25.18ca
30.25.08dd
30.25.19aa
30.27.4cc
30.25.33ca
30.25.33db
30.27.14bc
30.27.23dc
30.27.29ca
30.28.29cd
31.22.13ba
7/30/74
7/30/74
7/30/74
12/12/74
7/30/74
12/11/74
12/05/74
1/08/75
12/13/74
12/13/74
12/12/74
12/04/74
12/T3/76
12/04/74
12/04/74
8/22/73
8/22/73
2/26/75
8/22/73
3/11/75
315/110 LF
555/65 LF
525/93 LF
-/- UF
360/- LF
173/84 LF
772/196 LF
-/- LF/UF
-/- UF
-/- UF
700/272 LF
-/- UF
200/99 UF
-/- WT
39/37 WT
700/- LF
450/- LF
21/16 UF
800/- LF
15/10 WT
1.75 .052
1.1 .033
1.5 .045
0.96
0.54 * .027
.72
0.79
14.
0.58
1.5
0.37
1.6
7.3
0.26
0.23
3.4 t .068
3.7  .074
0.20
14.7 i .147
2.0

-------
GP70-13
M-M
GP71-46A
M-M
GP71A-30
M-M
EP72-27
M-N
GP73-47A
M-M
EP74-29
M-N
GP74A-40
M-M
GP74B-39
M-M
EP76-81
M-M
EP77-35
M-M
EP78-34
M-M
EP79-36
M-H
EP81-33
M-N
EP82-32
M-N
EP83-31
M-N
GP83A-29
M-N
EP84-30
M-M
GP84A-34
M-N
GP84B-32
N
Industrial well 21
Bradley Jet.
USGS monitor well
Domestic well at
grove W. of Agrico
Bradley Jet.
Church, Hwy 555 and 630
USGS monitor wel 1
USGS monitor well
Private well
Hwy. 17, 3/4 mile N. of Ft. Meade
Hwy. 17, h mile N. of Ft. Meade
Well in rest area on Hwy. 98 E. of
Ft. Meade
Ft. Meade well 2
Ft. Meade well 3
Ft. Meade well 1
USGS monitor well
2 miles W. of Ft. Meade
USGS monitor well
USGS monitor well
31.23.4ba
31.23.lldb
31.23,27da
31.24.7ab
31.24.15da
31.24.26cc
31.25.laa
31.24.4ba
31.25.20bc
31.25.22bb
31.25.22bd
31.25.25ca
31.25.27ba
31.25.27ba
31.25.27ca
31.25.28dc
31.25.30dd
31.26.17ba
31.26.23bc
12/13/74
12/12/74
2/25/75
9/10/74
12/02/74
9/10/74
2/25/75
2/26/75
12/05/75
9/10/74
9/10/74
9/07/74
9/10/74
9/10/74
9/10/74
2/25/75
9/10/74
3/19/75
3/19/75
289/20-52 WPb'
200/87 UF
16/11 WT
^
803/284 LF
-/-
31/21 WT
31/21 WT
-/- WT
175/126 UF'
42/21 WT
-'-
900/- LF
900/450 LF
850/- LF
23/18 UF
27/14 WT
39/34 UF
27/22 WT
1.2
4.5
0.28
< 2.0
1.4
< 2.0
1 .8
0.46
5.3
6.2 _ .124
< 2.0
< 2.0
< 2.0
< 2.0
< 2.0
0.32
* 2.0
7.7
0.20

-------
GP84C-27
M-M
EP85-12
M-N
GP85A-23
M-M
GP86-50
M-M
GP87-51
M-M
GP88-93
M-M
GP88A-19
M-M
GP88B-18
M-M
GP88C-26
M-N
GP88D-22
M-N
GP88E-20
M-N
GP88F-1
M-N
EP89-14
EP91-17
EP92-37
EM3-10
M-N
GM3A-5
M-N
EM4-7
M-N
EM5-8
M-N
EM8-1
M-N
USGS monitor well
Camp ground, Lake Wales
USGS monitor well
741156121-232 ,
Domestic well (*'
USGS monitor well
Bowling Green
USGS monitor well
USGS monitor wel 1
USGS monitor well
USGS monitor well
USGS monitor well
USGS monitor well
Trailer park, Frostproof
Trailer park
Kelley Rd. at Hwy 27A
(1 m. So. of Frostproof)
Domestic well
USGS monitor well
Domestic well
Private well, school
Private well, fire tower
31.26,31ad
31.27.10dd
32.23.13da
32.24.18aa
32.24.18bb
32.24.18bb
32.24.26cb
32.25.28cd
32.26.2bb
32.26.23bb
32.27.28ba
32.27.31cc
32.28.2dc
32.28.6bd
32.28.9bb
33.21.22cd
33.22.laa
33.22.15ba
33.22.20dd
34.21.32bc
12/10/75
8/22/73
2/25/75
12/05/74
12/13/74
12/03/74
2/26/75
2/26/75
3/19/75
2/27/75
3/12/75
3/12/75
8/22/73
8/22/73
9/10/74
6/24/75
2/25/75
6/24/75
6/24/75
6/24/75
122/84 UF
705/- LF
27/22 WT
-/60 WT
-/280 LF
23/20 WT
23/18 WT
22/17 WT
20/15 WT
27/22 WT
32/27 WT
51/46 UF
220/- UF
200/- UF
900/- LF
-/- ?
18/8 WT
93/63 WT
-/- ?
-/- ?
0.26
7.3 ' .073
0.20
3.4
0.14
4.4
0.54
0.20
0.20
22.
1.4
0.20
5.2 t .052
10.6 * .106
2.2 .066
0.40 ' .024
0.20
3.3 - .066
1.2 - .036
5.1 * .051

-------
GM10A-1
M-N
GM10B-2
M-N
GM10C-3
M-N
GM10D-4
M-N
EMI 3-1 5
N
EMI 4- 2
M-N
EMI 6- 16
EMI 8- 18
M-N
EMI 9-1 9
M-N
EM20-20
EM21-21
M-iJ
GHB-1
M-N
GHB-2
M-N
GHB-3
M-N
GHB-4
M-N
GHB-5
M-N
GHB-6
M-N
GHB-7
M-N
GH8-8
M-M
GH-1
M-N
Future phosphate mining area
Future phosphate mining area
Future phosphate mining area
Future phosphate mining area
Domestic well
Domestic wel 1
Domestic well
Domestic well
Domestic well
Domestic well
Domestic well
275006/821442
USGS monitor well
275110/820255
USGS monitor well
274033/820536
Domestic well
274216/820847
USGS monitor well
274544/821442
USGS monitor well
275514/820732
USGS monitor well'6'
275711/820329
old irrigation well
275918/820719
USGS monitor well
272954/814930
future phosphorus mine
34.22.19dd 1/29/75
34.22.19dd 1/29/75
34,22.19dd 1/29/75
34.22.19dd 1/29/75
35.19.22ba 6/24/75
35. 21. Sac 6/24/75
36.21.4cc 6/24/75
36.22.28da 6/24/75
37.22.7cb 6/24/75
37.22.12cb 6/24/75
37.22.17 6/24/75
3/17/75
3/11/75
12/10/74
2/26/75
2/25/75
3/11/75
2/25/75
2/25/75
12/03/74
1225/750
195/130
30/20
650/500
-/-
400/90
-/-
260/220
285/200
141/127
-'-
31/26
17/12
11/11
22/17
22/17
23/18
22/17
22/17
220/84
LF
LF
WT
LF
?
LF
t
LF
LF
LF
7
WT
WT
WT
WT
WT
WT
WT
WT
UF
4.7
0.54
..20
1 .4
0.11
12.1
1.1
5.0 1
4.0
3.9 i
3.7 f
.20
4.5
1.5
.20
.32
.20
.94
.94
1.5




.014
.121
.044
.10
.08
.078
.074









-------
to
--J
                             GH-2
                               M-N
                             6H-3
                               M-N
                              GH-4
                               M-N
                              GH-5
                               M-N

                              GH-6
                               M-N

                              GH-7
                               M-N

                              GH-8
                               M-N

                              GD-1
                               N-N
             272954/814930
             future phosphorus mine

             273516/814930
             USGS monitor well

             273528/813448
             USGS monitor well

             273532/814024
             USGS monitor well

             273540/815216
             USGS monitor well

             273541/820203


             273659/815639
              271303/815037
              near future  phosphate
              mining  area
12/03/74
3/12/75
3/12/75
2/27/75
2/25/75
2/25/75
2/26/75
12/03/74
32/21
17/12
17/12
26/21
17/12
18/13
23/18
320/141
WT
WT
WT
WT
WT
WT
WT
UF
.20
.24
.20
.05
.20
1.9
.20
7.9
(1)    Domestic well,  water level  97  feet  below  land  surface

(2)    Domestic well along edge of phosphate  mining district  in  a populated area

(3)    Near slime pit

(4)    Chemical waste  injection site

(5)    Uncased segment of well  also open to UF and LF;  drains water  from  surface aquifer  to  Floridan  aquifer  at  phosphate  mine

(6)    Well surrounded by an extensive area of mining and  tailings disposal

-------
             APPENDIX  2








 ANALYTICAL  RESULTS  FROM THE  1966  FWPCA  SURVEY




 OF RADIUM-226  IN  CENTRAL FLORIDA  GROUND WATER








(tables  III  and IV from  Shearer  et al.,  1966)
                   98

-------
                                  Municipal Well  Si.ippli.es  -  Central i''lQrjda

                                                                                                 Gross    Gross
Sample                        Depth of    Rn-222    Ra-226       U       a Th    Fb-210   Po-210   Alpha    Beta
Number    Municipal Supply    Well (ft)   (pc/l)^    (pc/l)    (p.g/1)   .(PJiZii   (pc/l)^   (pc/l)   (pc/l)    (pc/1^

  83    Eartow Well No. 3
        (RAW)                    650       260       1.6

        Bartow (Treated) -
        Aeration, Filtration,
        Clilorination                        80       l.k

  Qk-    Winter Haven Wells 1 and
        2 (RAW)               1-593       20       0.67
                              2 - 816

  85    Winter Haven Wells 3 and
        k (RAW)               3 - 6^8       95       0.58     1.2       0.12     o.O      0.0      2.7      2.7
  86    Lake Wales Well 1,
        Market St. Plant  (RAW)  1022        60      0.76       -         -        0.2       0.1      3.3      8.2

  87    Lake Wales Well 1,
        Grove Ave.Plant (RAW)   1063        35      0.47       -
88    Avon Park  (RAW)                     560      0.98     0.7      0.11      0.5       0.1      3.7
                                                                                                           3-7
  -89"-   Souring Franklin St.
        Well (RAW)              lll-80       140        -       0.7       0.11      0.2       0.1      O.h      3.8
  90    Arcadia Well 1  (RAW)     U95       ^80       3-3      0.9       0.52      0.6       0.1      k.$     2k

        Arcadia (Treated)
        Aeration, Chlorination             210       2.5
                                                                                                  (continued)

-------
                                                          Table  III (continued)
o
o
Sample
Wuinbc r
91

92
93
<*
95
96
97
98


99
100
101
102

Munic
Depth of
Municipal Supply Well (ft)
J3o'..'!l ing Green at
"Water Tank
Plant City Well 3
Plant City Well 2
Zcphyrhills
Dcidc City Well 1
Cler::iont South Well
Clermont Highland Well
L.OKC Alfred Well k (RAW)
Lake Alfred (Treated)
Ac; ration, Ciiiorination
Dundee Well at City Park
!I;iin-cG City Well 7
IlaineG City Well B


750
368
te5
150
525
550
560



Soo
565
ial_Well
En- 222
260
150
360
360
305
600
720
220

50
560
125
115
Supplies - Central Florida
Ra-226 U a T'n Pb-210
(pc/i) (nr;/i) (p'V'1) (PC/!)

2.7 0,o 0.15 0.3
0.77
0.00 1.2 0.06 0.1
0.31 1.2 0.00 0.3
0,00 -
0.39 -
0,29 1.8 o.ok o.l
k.l

1.8 -
0.0 - - 0.0
0.71!- -
0.73 -
Po-210
(pc/1)

0.3
-
0.0
0.0
-
-
0.0
-

-
0..0
-
-
                                                                                                          Gross    Croc

                                                                                                          Alpha    Beta

                                                                                                          ir_/ll   IPS/
                                                                                                                   11
                                                                                                           0..8
                                                                                                           0.7
                                         616
3JLO
0.50
        103    Aviburndale;  Water

               PLv,nt 'Well
                                                                                                            (continued)

-------
o
                                                         Table_ m  (continued)

                                         Municipal Well 'Supplies -  Central  Florida
Sample
Uiiniber
H*
105
106
107
iiui : i c. ipal 3u pply
y u . florlda Ave.
Lake-land Well 22
luilLcrry Well 1
 4edula Eecreation
Depth of
YJcll (ft)
865
891
778

En- 222
160
250
165

Ra-226 U
O..GO
0.84
0.45 1.4

O. Th
-
0.06

              Center - North oi'
              1-tu.rborry
320
0.23
                                                                                       Fb-210   Po-210
                                                                                        0.1
                                              0.1
                                                                                                 0.1
                                                                                                         GJ-O
                                                                Grose
                                                                j je"ca

-------
o
ro
      Cample
      Number
        3
        k
                                                         Table IV

                                         Privately  Owned Wells - Central i>'lorida
      Location
Depth of
Well (ft)
               H.W.  60 one mile west
               of Liii'Lov, Polk Cciuity  1100
H.W. 60 two miles west
of Bartow, Polk County   551

Ridge Wood Rod  and Gun
Club, 3 miles cast of
Mulberry, Polk  County    170
5      H.W.  5^8 five miles
       N.E.  of Mulberry,, Polk
       County                   300

6      H.W.  5'MDA one-half
       mile  couth of High-
       land c City>  Polk
       County                   155

7      1-1/2 miles north of
       Bartov,  polk County      200

8      II.W.  60 t'/o miles
       eact  of r/irto1..',  Polk
       County

9      H.W.  17 one  and one-
       half  ):i:iles so\ith of
       Aii'liO.oe^  rolk County
  76

 68o


2880


 210
                                                   95

                                                  970


                                                 3060


                                                 1030
   26      U



0.08


1.86



1.71     0.7
                                              .18
                                             0.69
                                1.5
                                                                        Pb-230   Po-2].0
                                                                              0.01
                                                  0.0
         0.0
        12
                                                                                                          23
0.0
0.1
                                                                                                           (continued)

-------
                                                 Table IV  (continued)
                                  Privately Owned Wells - Central Florida
Sample
Number

  10
  11
  12
  13
  Ik
  15


  16


  17
                      Depth of    Rn-222
      Location        Well (ft)   (pc/l)

H.U. 17 one mile
ooui/li of Airba.se,
Polk County               35      3550

H.W. 60 tvo miles
east of Mulberry,
Polk County               -       32^0

Intei-national Min-
erals Chemical Co.
(Bonnie Plant),
Polk County              900       860

0.1 miles east of
Bonnie Mine Rd. on
Pebbledale Ed.., Polk
County                    60      3890

1/2 mile vest of CCA
on Pebblcdale Rd.,
Polk County               -        990

H.W. 6hO at Jet. S.R.
555, Polk County          -     18,200

Bartov, 860 Herner St.
Poll: County               80      1010
Ra-226
(PC/1)
                                                    o.6l
                                                    0.12
 2.35
 0.21
                                                    1.19
  u
                                                             0.9
o.i
a Th
                   0.38
0.06
                  Gross   Gross
Fb-210   Po-210   Alpha   Beta
         .L/ii   (
                  0.6
 1.2
                  0.1
0.4
                           13
                                              0-9     15
                                                                                                 (continued)

-------
                                          Table IV (continued)
Privately Owned
Sample
Mumber
Depth of
Location Well (ft)
Rn-222
(pc/D
Wells -
Ka-226
(pc/D
Central
U
(nc/D
Florida
a Th
(PC/D
Fb-210
(rc/D
Po- 210
(pc/l).
Gross
Alpha
(pc/D
Gros
Beta
(Pc/
s
18    International Min-
      er; u.u  Chemical Co.,
      iloralyn  Plant,  Polk
      County                    92      8370

19    Homeland Rd.  1-1/2
      miles  north of Home-
      land,  Polk  County         98      '^730

20    One mile south of
      Bar'cow on Homeland
      Ed., Polk County         200      4l60

21    H.W. 17.  1-1/2 miles
      south  of Bartow,  Polk
      County                   89       4190

22    N.U.17.   3  miles
      couth  of Bartow,  Polk
      County                   160      5600
ILW. 5^5.  One mile
south of intersection
of il.W. yfi and II.W.
6-':0, Polk County
70    Ji 6, ooo
ijv;ift Co. East Deep
V.'oll, A^ricol'a, Florida,
Itolk County               oOO      1750
                                             2.70
                                             1.87
                                             1.0'f-
                                             1.99
1.89
                           2.2
                  0.03
                                    0.00
0.03
         0.8
                           0.5
0.2
                  0.2
10
                  10
                  16
                                                                                           (continued)

-------
o
01
                                                       Table  IV  (continued)
Sample
Number
25
26
27
28
29
30
31
32
33
Privately Owned
Depth of to- 222
Location Well (ft) (pc/l)
Svift Co. veil B-3, one
mile T-'oot of !>rift Co.,
Polk County 1100 2000
Minute Maid Co . , tvo
miles vest of Agricola - 28,800
Off Be vis Rd. two miles
vest of Ft. Meade, Polk
County 105 5780
Be vis Rd,, 2-1/2 miles
vest, of Ft. Meade, Polk
County - 22,700
K.W. 17, 1/2 mile north of
Ft. Meade,, Polk County 97 9750
II. U. 17, 1/2 mile north of
Ft. Meade, Polk County 187 10,850
Homeland, Polk County 105 ^80
Homeland, Polk County - ^130
Wells -
Ra-226
1.78
^9
5.22
76
0.21
5.13
2.68
2.11
Central Florida
U a Th
(|t(f/l) (pc/l)
l.'l- O.O^l-
11 0.37

IK 2 0.58




              Homeland, Polk County     88      2310      2.15
                                                                                                       Gross   Gross

                                                                                     Pb-210   Po-210   Alpha    Beta
                                                                                      o.:
                                                                                      7-6
                                                                                      3.7
o.o
1.5     75
0.8     97
16
                                                                                                        (continued)

-------
                                                        Table  IV  (continued)
                                         Privately  Ovned Wells  -  Central  Florida
Q
0>
      3ample
      Number

        35
        36
        37
        39
                       Depth of
       Location        Well (ft)

 Durant Section -
 Durtuii, Rd.  ab Tuikey
 Creek,  Ilillsborough
 County                   201

 Intersection of H.W.
 640  and Runyon Rd.,
 Iljllsborough County       90

 II. W.  60,  6  miles  vest
 of Mulberry,  Hills-
 borough County           150

 S.R.  60 and Coronet
 Rd.,  
-------
                                                  Table JV (continued)

                                   Privately Owned Wells  - Central Florida

                                                                                                  Gross    Gross
Sample                         Depth of    Rn-222   Ra-226      U      a Th    Fo-210   Po-210   Alpha    Be la
number        Location        Well (ft)   (pc/l)   (pc/l)   ilio/l).   (pc/l)   (pc/l)   jpc/l)   j_pe/l)_   (pc/l)

        II.W. 2'7A,  2  miles
        oGuuii uf i-'rOot Proof,
        Polk County                37        25      I-2

        H.W. 27A,  3  miles
        north of Gebring,
        Highlands  County         300      3330      2.3        -        -       0.2      0.2       5       13

        II.W. 27, 7 mile
        south of Sebring,
        Hic!i3.ands  County          69        23      lA2

        Grassy I,
-------
                                                        Table IV  (continued)
o
00
Privately Owned Wells -
Sample
Numbe r

Location
4 9 11. W. 17, one mile
north of Wanchula,
Hardee County
50*
51*
H.W
Spi-
ll. W
. 39, at Crystal
ings, Pasco County
. 50, 2 miles east
Depth of
Well (ft)
85
36

Rn-222 Ra-226
(pc/l) (pc/l)
kOhO 0 . kk
U70 0.82

Central Florida
U a Th
(uS/l) (pc/l).
0.8 0.09


Gross
Pb-210 Po-210 Alpha
(pc/l) (pc/l) (pc/l)
0.1 0.1 2


Gross
Beta
(pc/D
13


      of I/inter Garden,  Orange
      County                     -        365      0.^9

52*   H.W. 1*393,  l.k miles ^
      south of  II.W.  50,  Orange
      County                     -       2780      2.33

53*   H.W. 17,  2 Miles south
      of Kicsiiumee,  Osceola
      County                  60 - 70     153

5^*   H.W. 17,  5 miles south
      of Kissiixiee,  Osceola
      County                  90 - 115    870      2.17

55*   II.W. 17,  south of
      Kinsii.mee,  Osceola
      County                     7^      1350      0.1*3

56    1.5 miles  vest of  Haines
      City off H.W.  92,Polk Co. 200     23^0      3.9
                                                                    0.1
0.04
0.0
0.1
                                                                                                          (continued)

-------
                                                 Table.IV (continued)

                                  Privately Owned Wells - Central Florida

                                                                                                Gross    Gross
Sample                        Depth of    Rn-222   Ra-226      U      a Th    Fo-210   Po-210   Alpha    Beta
Number        Location        Well (ft)   (pc/l)   (pc/l)   (iWl)   (pc/l)    (pc/l)   (pc/l)   (pc/l)   (pc/l)

  57    3.5 niles east of Lake-
        land off II. W.  92, Polk
        County                   162      i860      2.7

  58    3-5 miles east of Lake-
        land off H.W.  92, Polk
        County                    53      2610      0-75

  59    2.5 miles east of Lake-
        land off H.W.  92, Polk
        County                   150      6210

  60    H.W. 542, one  mile east
        of Lakeland,  Polk County  27    10,000      1.20     1.4      0.04     0.7      0.4      1.9      0

  6l    Intersection of Fields Rd.
        and H.W. 542 east of Lake-
        land,  Polk County        287      3810      1.89

  62    Old Auburndale Rd. 4 miles
        east of Lakeland, Polk
        County                   120      2410      3.58

  63*    H.W. 92, 1.75  miles vest
        of Plant City, Hills-
        borough County           134       550      0.03

  64*    H.W. 92, 2 miles east of
        H.W. 579, Hillsborough
        County '                 150       240      0.02

-------
                                                 Table IV  (continued)
                                   Privately Owned Wells - Central Florida
Sample
Humbe r

  65*
  66*

  67*


  68*


  69


  70
  71
Location
Depth of
Well (ft)
Intersection  of H.W.  301
cu id Puliil Rlvt: i' Rd . ,
uplllsborough  County       80

River View, Hillsborough
County

II.W. 301,  .75 mile south
of Alafia  River Bridge,
Hillsborough  County

H.W. 301,  2.5 miles
south of Riverviev,
Hillsborough  County       96

II.W. 672,  2 miles vest
of Picnic, Hillsborough
County                   187

Intersection of H.W.
672 and II.W. 39 at
Picnic, Hillsborough
County

Intersection of H.W.
and H.W. 39 at Ft. Lone
some,  Hillsborough Co.
Rn-222
(PC/1)
                                          2020
                             750
                             630
                            3^00
                                          7650
                                          2650
Ra-226
(pc/D
                      0.30
                                      1-93
                      1.73
                      0.3
                                      0.28
                                      0.33
U
                               0.8
                                                        a. Th
                            0.04
                            0.01
                                                                                                 Gi'oss
                            0.2
                            0.6
                         0.1
                         0.1
                   o.k
                                                                                           Gross
Pb-210   Po-210   Alpha    Leta
(pc/l)   (pc/1)   (pc/1)   (pc/1)
                                                                    0.3      0

                                                                    (continued)

-------
                                               Table TV (continued)
Privately Owned

Sample
Number Location

Depth of
Well (ft)

Bn-222
(pc/1)
Wells - Central Florida

Ra-226
(pc/1)

(MS/I)

a ih
(pc/1)

Pb-210
(pc/1)

Po-210
(pc/1)
Gross
Alpha
(pc/1)
Gross
Beta
(pc/1
72    H.. 630, 1.7 miles
      west of Armour Ft.
      Meade, Polk County

73    k miles south of
      .Mulberry on "E.W. 37,
      Po.lk County

74    Bradley Jet., 6.5
      miles soutli of Mul-
      berry, Polk County

75    Bradley Jet., 7 miles
      sou tli of Mulberry,
      Polk County

76    One mile couth of
      Bradley Jet., Polk
      County

77    Intersection of new
      and old H.W, 37,
      Polk County

78    Old H.W. 37 south into
      Bradley Jet., Polk Co.
  143    11,300      7.41     1.6


  200      5120      2.14     1.4



  183      7330      3-90


           2070      o.ll     1.4


So - 90    9460      4.32



           3300      1.31


   15      7600     19
o.ok
0.11
1.3
0.3
0.03     0.4
0.3
0.2
         0.1
12
                                                                                               (continued)

-------
                                                 Table  IV  (continued)

                                   Privately  Owned Wells -  Central Florida

                                                                                                Gross    Gross
Sample                         Depth  of     Rn-222   Ra-226      U      a Th    Fb-210   Po-210   Alpha    Beta
Number        Location         Well (ft)    (pc/l)   (pc/l)    (nc/l)    (pe/l)   (pc/l)   (pc/l)   (pc/l)   (pc/l)

  79    Bradley Jet., Polk Co.     -        1480      1.31

  80    Rolling Mills,  Polk
        CouuLy                     -        6550      2.3     1.4      0.04     0.7      0.3

  8.1    Oak Terrace, Polk Co.      -        8680      4.6

  82    Oak Terrace, Polk Co.      -        8430      0.0
*  Considered outside of area.

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                       APPENDIX 3.  WELL NUMBERING SYSTEM

     The well numbering system used in this report is based on the Federal
system of land divisions.   Data from the U. S. Geological Survey are located
by latitude and longitude and are additionally located herein by township and
range.

     Under the Federal system of land divisions, a location is specified in
terms of three principal parts:  township (T), range (R), and section (S).  In
the study area, townships are measured northward at six-mile intervals  from
the meridian.  An area of 36 square miles is defined by a given township and
range and, for example, is stated as T.27S., R.25E.  Within a given township
there are 36 sections of one square mile each (640 acres) and numbered  from 1
to 36 as shown below.  The letters a, b, c, and d designate, respectively, the
northeast, northwest, southwest, and southeast quadrants.  The first letter
designates the quarter section (160 acre tract) and the second letter indicates
the quarter quarter  section  (40 acres).  A well located in the NW3* SW3*,  sec.24
T.27S., R.25E. would  be numbered 27.25.24cb.  This is illustrated follows:
                 R25E
                                  27 25 24 cb
                                          113

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Site No
SI
S2
S3
S4
S5
S6
S7
S8
S9
S10
Sll
S12
S13
S14
S15
S16
SI 7
S18
S19
S20
S21
S22
S23
S24
S25
S26
S27
APPENDIX 4. DISSOLVED
Name of Well
TRAILER PARK
TRAILER PARK
TRAILER COURT
BUSINESS ESTABLISHMENT
MOBILE HOME PARK
APARTMENTS
MOBILE HOME PARK
FRUITVILLE ELEMENTARY SCHOOL
VENICE CAMPGROUNDS
ORGANIZATION OFFICE
NOKOMIS ELEMENTARY SCHOOL
TRAILER PARK
TRAILER PARK
CLUB
ASHTON-BLISS SCHOOL
PARK PICNIC AREA
PARK PICNIC AREA
PARK PICNIC AREA
PARK PICNIC AREA
PARK PICNIC AREA
PARK CONCESSION STAND
PARK CONCESSION STAND
PARK CONCESSION STAND
PARK CONCESSION STAND
PARK CONCESSION STAND
PARK
MOBILE HOME PARK
RADIUM
Sample
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
- 226 CONCENTRATION (pCi/1) IN GROUND
Code T.R.S Date Sampled
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
1793
1796
40
37
38
36
38
37
28
36
39
37
39
37
37
37
37
38
38
38
38
38
37
37
37
37
37
36
37
.19.
.18.
.18.
.18.
.18.
.18.
14
20
3
24
10
29
.18.25
.18.
.20.
.18.
.19.
.18.
.18.
.17.
.18.
.18.
.18.
.18.
.18.
.18.
.20.
.20.
.20.
.20.
.20.
.18.
.18.
24
21
18
6
7
13
13
11
14
14
14
14
14
15
15
15
15
15
15
12
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
2/25/76
9/9/75
9/9/75
9/9/75
9/9/75
9/9/75
<)/9/7r>
9/9/75
9/9/75
9/9/75
9/9/75
8/7/75
8/7/75
WATER IN SARASOTA COUNTY '
Dissolved
Aquifer Radium - 226 (pC1/l)
F2
F
F
F
F
F
F
F
F
F
F
F
F
F
F
WT3
WT
WT
WT
WT
WT
WT
WT
WT
WT
F
F
19.
17.
14.
21.
3
8
9
,7
5.4
13.
15.
12.
12.
8.
12.
10.
10,
4.
3.
23.
22
24
23
24
11
12
14
,0
0
4
3
,9
,1
.3
1
.8
.5
.0
.3
.0
.5
.4
.8
.1
.1
14.5
14,
5,
6.
.1
.1
5
 .015
+ .014
+ .012
 .015
 .054
 .12
 .14
 .12
 .12
 .089
 .12
 .10
 .10
 .096
 .070
 .28
 .27
 .29
 .28
 .29
 .11
 .11
 .13
 .12
.13
 .051
.52

-------
S28
S29
S30
S31
S32
S33
S34
S35
S36
S37
S38
S39
S40
S41
S42
S43
S44
S45
S46
S47
548
S49
CITY OF VENICE
UTILITY
PARK CONCESSION STAND
UTILITY CO.
MOBILE HOME PARK
ENGLEWOOD WATER DISTRICT
MOBILE HOME PARK
MOBILE HOME PARK
MOBILE HOME PARK
TRAILER PARK
STATE PARK
CITY OF SARASOTA
MOBILE HOME PARK
MOBILE HOME PARK
OSPREY SCHOOL
WATER COMPANY
MOBILE HOME PARK
UTILITY
UTILITY
UTILITY
PHILLIPI SHORES SCHOOL
UTILITY
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
PW -
1997
1799
1800
1801
1802
1803
1805
1806
1807
1808
1809
1810
1812
1814
1815
1816
1817
181S
1819
1821
1822
1823
39.
36.
37.
39.
36.
40.
37.
39.
36.
36,
17.
7
18.6
20.
19,
18,
,20.
19,
19,
.19
.18
38.18
36,
38
38.
38.
36.
40.
36.
38.
36.
37.
37.
.20
.18
18.
18,
18.
19.
18.
,15
,26
,27
.31
.5
,23
.19
.28
.14
.4
.3
.25
,3
,32
4
11
18.23
18.
18.
17.
35
5
12
8/?/75
8/7/75
8/7/75
8/?/75
8/8/75
8/7/75
8/7/75
8/7/75
8/7/75
8/7/75
8/?/75
8/7/75
8/7/75
8/?/75
8/7/75
8/7/75
8/7/75
8/7/75
8/8/75
8/7/75
8/7/75
8/8/75
F
f
WT
F
F
T
F
f
F
F
WT
F
F
F
--
F
F
F
F
F
F
F
8.5
2.1
14.7
10.8
8.1
1.5
3.6
4.0
8.7
6.0
7.3
4.2
27
15. 3
7.3
6.8
1.6
3.6
4.6
3.5
11.7
4.9
 .085
.042
-t
+ ,
+ _
T<
+ f
,13
12
081
045
072
.080
+t
+,
087
060
.073
.084
+_
+
t
t
.
+
-).
-
+
-
15
.14
.073
.068
.048
.072
.046
.070
.12
.098
1  Data supplied by Sarasota Cou.ity Health Department
2  Floridan aquifer
3  Water table aquifer

-------
                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
  REPORT NO.
  EPA/520-6-77-010
                                                           3. RECIPIENT'S ACCESSI ON-NO.
4. TITLE AND SUBTITLE
                   Effects  of Phosphate Mineralization
and the Phosphate  Industry on Radium-226 in Ground
Water of Central  Florida
5. REPORT DATE
   October 1977
                                                           6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
 Robert F.  Kaufmann
 James D.  Bl iss
                                                           8. PERFORMING ORGANIZATION REPORT NO.
9 PERFORMING ORGANIZATION NAME AND ADDRESS
 Office of Radiation Programs  -  Las  Vegas Facility
 U.S.  Environmental Protection Agency
 P.  0.  Box 15027
 Las Vegas, Nevada  89114
                                                           10. PROGRAM ELEMENT NO.
                                                          11. CONTRACT/GRANT NO.
 12. SPONSORING AGENCY NAME AND ADDRESS
                                                           13. TYPE OF REPORT AND PERIOD COVERED
                                                             Final
 Same as above
                                                           14. SPONSORING AGENCY CODE
                                                             200/03
 15. SUPPLEMENTARY NOTES
                                                                          characterize
 is. ABSTRACT
                Dissolved  radium-226 data were statistically  analyzed to
 water quality  in  the  water table, Upper Floridan and  Lower  Floridan aquifers in  six
 counties of west  central  Florida where major strip mining and  beneficiation of phos-
 phate deposits  is underway.   Mineralization and mining  have not significantly
 increased  the  dissolved  radium content of native ground water,  although locally
 elevated levels of radium in both mineralized and nonmineralized areas are naturally
 present.   In Hillsborough, Polk, Hardee, and De Soto  Counties,  mean radium content of
 ground water beneath  mined and unmined lands is 5 pCi/1  or  less, with maximum values
 on the order of 15 to 20 pCi/1 occurring in unmined areas.   For Sarasota and Manatee
 Counties,  average radium content is 4 to 15 pCi/1 in  the water table and Floridan
 aquifers.  Although portions of these latter two areas  are  mineralized, there has  been
 no mining  activity to date.   Other hydrogeologic and  hydrogeochemical factors such as
 position near  the discharge portion of the ground-water flow system and increased
 radium solubility in-water enriched in IDS are believed responsible for the elevated
 concentrations, particularly in the Floridan aquifer  in Sarasota County.  The radium-
 226 data base  collected  in the period 1966 to present is marginal for determining
 environmental  quality trends and spatial or temporal  variations because too few
 samples  have been collected and diverse sample handling procedures affect the values
 produced.  Recommendations for additional monitoring  and technical studies  are
 Outlined to  -inipr""g v/ator and land managpmpnt __ _____
17.
                               KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
 Ground water
 Hydrogeology
 Water pollution
 Water quality
 Radium
 Phosphate  deposits
 Statistical  inference
                                             b.IDENTIFIERS/OPEN ENDED TERMS
                                              Florida hydrology study
                                              Phosphate mining
                                              Radiation surveys
                                              Environmental  surveys
                                                                        c.  cos AT l Field/Group
                1808
                0807
                0808
 3. DISTRIBUTION STATEMENT
 Release  unlimited
                                              19. SECURITY CLASS (ThisReport)
                                               Unclassified
                                                                        21. NO. OF PAGES
                                                                          125
                                              20. SECURITY CLASS (This page)
                                               Unclassified
                                                                        22. PRICE
EPA Form 2220-1 (9-73)
                                                              *U. S. GOVERNMENT PRINTING OFFICE: 1977-785-037

-------