Analysis of Nonpoint-Source Ground-Water Contamination in ...

Analysis of Nonpoint-Source Ground-Water Contamination in Relation to Land Use: Assessment of Nonpoint-Source Contamination in Central Florida

United States Geological Survey Water-Supply Paper 2381-F

Prepared in cooperation with the Florida Department of Environmental Protection

Analysis of Nonpoint-Source Ground-Water Contamination in Relation to Land Use: Assessment of Nonpoint-Source Contamination in Central Florida

By E.R. German

Prepared in cooperation with the

Florida Department of Environmental Protection

U.S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 2381-F

U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY Gordon P. Eaton, Director

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Printed in the Eastern Region, Reston, Va.

UNITED STATES GOVERNMENT PRINTING OFFICE: 1996

For sale by the U.S. Geological Survey, Map Distribution Box 25286, MS 306, Federal Center Denver, CO 80225

Library of Congress Cataloging in Publication Data

German, E.R.

Analysis of nonpoint-source ground-water contamination in relation to land use:

Assessment of nonpoint-source contamination in central Florida/ by E.R.

German.

p. cm. --(U.S. Geological Survey water-supply paper; 2381-F)

"Prepared in cooperation with the Florida Department of Environmental

Protection."

Includes bibliographical references.

Supt. of Docs. no: x xx.xx:W2381-F

1. xxxxxxx--Florida--Central Florida

I. German, E.R.. II. Florida Department of Environmental Protection III. Title.

IV. Series.

XXXXX.XX 1995 XXX.XX'XXXXX'XX--xxXX

XX-XXXX

CIP

CONTENTS

Abstract.................................................................................................................................................................................. 1 Introduction ........................................................................................................................................................................... 2 Description of the Study Areas.............................................................................................................................................. 4

Climate......................................................................................................................................................................... 4 Topography .................................................................................................................................................................. 4 Geohydrologic Units.................................................................................................................................................... 5 Control Area ................................................................................................................................................................ 5 Urban Area .................................................................................................................................................................. 7 Citrus Area................................................................................................................................................................... 9 Mining Area.................................................................................................................................................................10 Areas Selected for Assessment of Transferability of Study Results ...........................................................................12

Urban Area ........................................................................................................................................................12 Citrus Area.........................................................................................................................................................13 Previous Work .......................................................................................................................................................................13 Method of Investigation.........................................................................................................................................................15 Sampling-Site Selection ..............................................................................................................................................16 Control Area: Surficial Aquifer System ............................................................................................................16 Control Area: Upper Floridan Aquifer System .................................................................................................16 Urban Areas.......................................................................................................................................................16 Citrus Areas .......................................................................................................................................................17 Mining Area.......................................................................................................................................................18 Well Construction ........................................................................................................................................................18 Sampling and Analytical Procedures...........................................................................................................................19 Constituents Analyzed .................................................................................................................................................20 Data Analysis...............................................................................................................................................................21 Potential for Contamination of Ground Water from Nonpoint Sources ................................................................................23 Age of Ground Water as an Indication of Contamination Potential............................................................................23 Potential Contaminant Sources and Contaminants......................................................................................................24 Control Area ......................................................................................................................................................24 Urban Area ........................................................................................................................................................24 Citrus Area.........................................................................................................................................................25 Mining Area.......................................................................................................................................................27 Effects of Land Use on Ground-Water Quality .....................................................................................................................28 Major Constituents, Properties, Nitrogen Species, Phosphorus, and Unidentified Organic Compounds ...................28 Trace Elements ............................................................................................................................................................32 Volatile, Base-Neutral-Extractable, and Acid-Extractable Compounds......................................................................32 Pesticides .....................................................................................................................................................................35 Assessment of Transferability of Study Results ....................................................................................................................35 Urban Areas.................................................................................................................................................................36 Citrus Areas .................................................................................................................................................................38 Summary and Conclusions ....................................................................................................................................................39 References .............................................................................................................................................................................41

Contents III

Appendix I. Summary of Water-Quality Characteristics for Ground Water Beneath Various Land-Use Areas in Central Florida ................................................................................................................ .............................. 47

Appendix II. Summary of Water-Quality Data: Volatile Organic Compounds in Ground-Water Beneath Various Land-Use Areas in Central Florida ............................................................................................................... 51

Appendix III. Summary of Pesticides Concentrations in Ground Water Beneath Various Land-Use Areas in central Florida 54

Appendix IV. Summary of Trace-Element Concentrations in Ground Water Beneath Various Land-Use Areas in Central Florida .............................................................................................................................................. 56

FIGURES

1. Map showing locations of study areas..................................................................................................................... 3 2. Diagram showing generalized geohydrologic columns in the four study areas in central Florida

(thickness of units other than the Upper Floridan aquifer, as drawn, indicate average thickness of units, modified from Rutledge, 1987)............................................................................................................................... 5 3. Map showing the control area and locations of sampled wells................................................................................ 6 4. Diagram showing generalized geohydrologic section through the control area in the Ocala National Forest (modified from Rutledge, 1987) ............................................................................................................................. 7 5. Map showing the urban study area in Orlando, Fla., and locations of sampled wells and drainage wells.............. 8 6. Diagram showing generalized geohydrologic section through the urban area in Orlando, Fla............................... 9 7. Map showing the citrus study area near Windermere, Fla., and locations of sampled wells................................... 10 8. Diagram showing generalized geohydrologic section through the citrus area near Windermere, Fla. (modified from Rutledge, 1987) ........................................................................................................................... 11 9. Map showing the phosphate mining study area near Bartow, Fla., and locations of sampled wells ...................... 12 10. Diagram showing generalized geohydrologic section through the mining area near Bartow, Fla. (modified from Rutledge, 1987) .............................................................................................................................................. 13 11. Map showing the urban study area in Ocala, Fla., and locations of sampled wells ................................................ 14 12. Map showing the citrus study area near Lake Wales, Fla., and locations of sampled wells ................................... 15 13. Graph showing tritium concentration in rainfall at Ocala, Fla., 1961-87 ............................................................... 23 14-17. Box plots showing: 14. Specific conductance and calcium, potassium, and sulfate concentrations in ground

water in the study areas, April 1984 through September 1989......................................................................... 29 15. Nitrogen and phosphorus species concentrations in ground water in the study areas,

April 1984 through September 1989 ................................................................................................................ 30 16. Arsenic, cadmium, chromium, and copper concentrations in the study areas,

April 1984 through September 1989................................................................................................................. 33 17. Iron, lead, manganese, and zinc concentrations in the study areas, April 1984

through September 1989 .................................................................................................................................. 34

TABLES

1. Surficial aquifer system wells sampled in the control area............................................................................................ 16 2. Upper Floridan aquifer wells sampled in the control area ............................................................................................. 16 3. Wells sampled in the urban area in Orlando .................................................................................................................. 17 4. Wells sampled in the urban area in Ocala ...................................................................................................................... 17 5. Wells sampled in the citrus area near Windermere ........................................................................................................ 18 6. Wells sampled in the citrus area near Lake Wales ......................................................................................................... 18 7. Wells sampled in the mining area near Bartow.............................................................................................................. 19 8. Types of analyses performed on ground-water samples ................................................................................................ 20 9. Analytical schedules for volatile, base-neutral-extractable and acid-extractable organic compounds.......................... 21 10. Analytical schedule for pesticide compounds................................................................................................................ 22 11. Tritium concentration in water from wells in the control, urban, and citrus areas ........................................................ 24 12. Inventory of pesticide usage .......................................................................................................................................... 26 13. Summary of statistically significant land-use effects on ground-water quality ............................................................. 31

IV Contents

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download